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Withanage NC, Mishra PK, Abdelrahman K, Singh R. Monitoring deforestation, forest health, and environmental criticality in a protected area periphery using Geospatial Techniques. PeerJ 2024; 12:e17714. [PMID: 39035152 PMCID: PMC11260410 DOI: 10.7717/peerj.17714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 06/18/2024] [Indexed: 07/23/2024] Open
Abstract
Protected areas in South Asia face significant challenges due to human disturbance and deforestation. The ongoing debate surrounds the recent surge in illegal encroachment of forest buffer zones in the Musali divisional secretariat division (DSD), which has led to a significant loss of forest cover over the past three decades. In this context, detecting changes in forest cover, assessing forest health, and evaluating environmental quality are crucial for sustainable forest management. As such, our efforts focused on assessing forest cover dynamics, forest health, and environmental conditions in the DSD from 1988 to 2022. We employed standardized image processing techniques, utilizing Landsat-5 (TM) and Landsat-8 (OLI) images. However, the forest area in the DSD has shown minimal changes, and environmental conditions and forest health have illustrated considerable spatial-temporal variations over the 34 years. The results indicated that 8.5 km2 (1.9%) of forest cover in the DSD has been converted to other land use classes. Overall, the Normalized Difference Vegetation Index (NDVI) has declined over time, while Land Surface Temperature (LST) exhibits an increasing trend. The regression results demonstrated a robust inverse relationship between LST and NDVI. The declining vegetation conditions and the increasing LST contribute to an increase in environmental criticality. The derived maps and indices will be beneficial for forest authorities in identifying highly sensitive locations. Additionally, they could enable land use planners to develop sustainable land management strategies.
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Affiliation(s)
- Neel Chaminda Withanage
- School of Geographical Science, Southwest University, Beibei District, Chongqing, PR China, China
- Department of Geography, Faculty of Humanities and Social Sciences, University of Ruhuna, Wellamadama, Matara, Sri Lanka
| | - Prabuddh Kumar Mishra
- Department of Geography, Shivaji College, University of Delhi, New Delhi, Delhi, India
| | - Kamal Abdelrahman
- Department of Geology and Geophysics, King Saud University, Riyadh, Saudi Arabia
| | - Rajender Singh
- Department of Geography, Shivaji College, University of Delhi, New Delhi, Delhi, India
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Fan Y, Feng Q, Huang Y, Yang N, Fan H, Li B, Wang X, Yang L, Yen H, Wu F, Chen L. Determining optimal range of reduction rates for nitrogen fertilization based on responses of vegetable yield and nitrogen losses to reduced nitrogen fertilizer application. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171523. [PMID: 38453078 DOI: 10.1016/j.scitotenv.2024.171523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 02/21/2024] [Accepted: 03/04/2024] [Indexed: 03/09/2024]
Abstract
Vegetable production is commonly accompanied by high nitrogen fertilizer rates but low nitrogen use efficiency in China. Reduced fertilization has been frequently recommended in existing studies as an efficient measurement to avoid large amount of nutrient loss and subsequent nonpoint source pollution. However, the reported responses of vegetable yield and nitrogen losses to reduced fertilization rates varied in a large range, which has resulted into large uncertainties in the potential benefits of those recommended reduction rates. Thus, we constructed the relationship between responses of nitrogen losses and vegetable yield to reduced nitrogen fertilization rates to determine the optimal range of reduction rates for nitrogen fertilization in a proportional form based on data reported in literatures across China's mainland, and evaluated the roles of greenhouse, managing options, and vegetable species on the responses. The relationships were constructed separately for 4 subregions: Northern arid and semiarid, loess plateau regions (NSL), Temperate monsoon zone (TMZ), Southeast monsoon zone (SMZ), Southwest zone (SWZ). The optimal nitrogen fertilizer reduction range for the TMZ, SMZ and SWZ were 51 % to 67 %, 40 % to 66 % and 54 % to 80 %, respectively and no reduction for NSL. Vegetable yields were not be sacrificed when fertilizations were reduced within the optimal ranges. Greenhouse and managing options showed no significant effect on the responses of both vegetable yield and nitrogen losses by the optimal reduction range but vegetable species played a relatively important role on the responses of vegetable yield. This indicated that the optimal reduction rates can be effective on reducing nitrogen loss in both open-field and greenhouse conditions across China's mainland without extra managing options. Therefore, the optimal reduction rates can still serve as a good starting point for making regional plans of nitrogen reduction that help balancing the chasing of high vegetable yield and low nitrogen loss.
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Affiliation(s)
- Yinlin Fan
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650091, China
| | - Qingyu Feng
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Yong Huang
- Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650091, China
| | - Nengliang Yang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; Institute of International Rivers and Eco-Security, Yunnan University, Kunming 650091, China
| | - Huihui Fan
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Boyong Li
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xinyan Wang
- School of Landscape Architecture, Beijing Forestry University, Beijing 100091, China
| | - Lei Yang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Haw Yen
- School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849, USA; Environmental Exposure Modeling, Regulatory Science North America, Bayer US Crop Science Division, Chesterfield, MO 63017, USA
| | - Feng Wu
- Center for Chinese Agricultural Policy, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Liding Chen
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
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3
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Mahato T, Parida BR, Bar S. Assessing tea plantations biophysical and biochemical characteristics in Northeast India using satellite data. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:327. [PMID: 38421498 DOI: 10.1007/s10661-024-12502-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 02/24/2024] [Indexed: 03/02/2024]
Abstract
Despite advancements in using multi-temporal satellite data to assess long-term changes in Northeast India's tea plantations, a research gap exists in understanding the intricate interplay between biophysical and biochemical characteristics. Further exploration is crucial for precise, sustainable monitoring and management. In this study, satellite-derived vegetation indices and near-proximal sensor data were deployed to deduce various physico-chemical characteristics and to evaluate the health conditions of tea plantations in northeast India. The districts, such as Sonitpur, Jorhat, Sibsagar, Dibrugarh, and Tinsukia in Assam were selected, which are the major contributors to the tea industry in India. The Sentinel-2A (2022) data was processed in the Google Earth Engine (GEE) cloud platform and utilized for analyzing tea plantations biochemical and biophysical properties. Leaf chlorophyll (Cab) and nitrogen contents are determined using the Normalized Area Over Reflectance Curve (NAOC) index and flavanol contents, respectively. Biophysical and biochemical parameters of the tea assessed during the spring season (March-April) 2022 revealed that tea plantations located in Tinsukia and Dibrugarh were much healthier than the other districts in Assam which are evident from satellite-derived Enhanced Vegetation Index (EVI), Modified Soil Adjusted Vegetation Index (MSAVI), Leaf Area Index (LAI), and Fraction of Absorbed Photosynthetically Active Radiation (fPAR), including the Cab and nitrogen contents. The Cab of healthy tea plants varied from 25 to 35 µg/cm2. Pearson correlation among satellite-derived Cab and nitrogen with field measurements showed R2 of 0.61-0.62 (p-value < 0.001). This study offered vital information about land alternations and tea health conditions, which can be crucial for conservation, monitoring, and management practices.
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Affiliation(s)
- Trinath Mahato
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India
- Centre for Environment and Energy Development, Ranchi, 834001, India
| | - Bikash Ranjan Parida
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India.
| | - Somnath Bar
- Department of Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
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Villanueva G, Plazas M, Gramazio P, Moya RD, Prohens J, Vilanova S. Evaluation of three sets of advanced backcrosses of eggplant with wild relatives from different gene pools under low N fertilization conditions. HORTICULTURE RESEARCH 2023; 10:uhad141. [PMID: 37575654 PMCID: PMC10421729 DOI: 10.1093/hr/uhad141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/08/2023] [Indexed: 08/15/2023]
Abstract
The development of new cultivars with improved nitrogen use efficiency (NUE) is key for implementing sustainable agriculture practices. Crop wild relatives (CWRs) provide valuable genetic resources for breeding programs aimed at achieving this goal. In this study, three eggplant (Solanum melongena) accessions together with their advanced backcrosses (ABs; BC3 to BC5 generations) were evaluated for 22 morpho-agronomic, physiological, and NUE traits under low nitrogen (LN) fertilization conditions. The ABs were developed with introgressions from the wild relatives Solanum insanum, Solanum dasyphyllum, and Solanum elaeagnifolium. The AB population comprised a total of 25, 59, and 59 genotypes, respectively, with overall donor wild relative genome coverage percentages of 58.8%, 46.3%, and 99.2%. The three S. melongena recurrent parents were also evaluated under control (normal) N fertilization. Reduction of N fertilization in the parents resulted in decreased chlorophyll content-related traits, aerial biomass, stem diameter, and yield and increased NUE, nitrogen uptake efficiency (NUpE), and nitrogen utilization efficiency (NUtE). However, the decrease in yield was moderate, ranging between 62.6% and 72.6%. A high phenotypic variation was observed within each of the three sets of ABs under LN conditions, with some individuals displaying improved transgressive characteristics over the recurrent parents. Using the single primer enrichment technology 5 k probes platform for high-throughput genotyping, we observed a variable but high degree of recurrent parent genome recovery in the ABs attributable to the lines recombination, allowing the successful identification of 16 quantitative trait loci (QTL). Different allelic effects were observed for the introgressed QTL alleles. Several candidate genes were identified in the QTL regions associated with plant growth, yield, fruit size, and NUE-related parameters. Our results show that eggplant materials with introgressions from CWRs can result in a dramatic impact in eggplant breeding for a more sustainable agriculture.
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Affiliation(s)
- Gloria Villanueva
- Instituto de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, Camino de Vera 14, 46022, Valencia, Spain
| | - Mariola Plazas
- Instituto de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, Camino de Vera 14, 46022, Valencia, Spain
| | - Pietro Gramazio
- Instituto de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, Camino de Vera 14, 46022, Valencia, Spain
| | - Reyes D Moya
- Instituto de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, Camino de Vera 14, 46022, Valencia, Spain
| | - Jaime Prohens
- Instituto de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, Camino de Vera 14, 46022, Valencia, Spain
| | - Santiago Vilanova
- Instituto de Conservación y Mejora de la Agrodiversidad Valenciana, Universitat Politècnica de València, Camino de Vera 14, 46022, Valencia, Spains
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Ye X, Kitaya M, Abe S, Sheng F, Zhang S. A New Small-Size Camera with Built-In Specific-Wavelength LED Lighting for Evaluating Chlorophyll Status of Fruit Trees. SENSORS (BASEL, SWITZERLAND) 2023; 23:4636. [PMID: 37430550 DOI: 10.3390/s23104636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/28/2023] [Accepted: 05/05/2023] [Indexed: 07/12/2023]
Abstract
To produce high-quality crops, not only excellent cultivation techniques but also accurate nutrient management techniques are important. In recent years, many nondestructive tools such as the chlorophyll meter "SPAD" and the leaf nitrogen meter "Agri Expert CCN" have been developed for measuring crop leaf chlorophyll and nitrogen contents. However, such devices are still relatively expensive for individual farmers. In this research, we developed a low-cost and small-size camera with built-in LEDs of several specific wavelengths for evaluating the nutrient status of fruit trees. A total of 2 camera prototypes were developed by integrating 3 independent LEDs of specific wavelengths (Camera 1: 950 nm, 660 nm and 560 nm; Camera 2: 950 nm, 660 nm and 727 nm) into the device. In addition, a simple software tool was developed to enable the camera to capture leaf images under different LED lighting conditions. Using the prototypes, we acquired images of apple leaves and investigated the possibility of using the images to estimate the leaf nutrient status indicator SPAD (chlorophyll) and CCN (nitrogen) values obtained using the above-mentioned standard tools. The results indicate that the Camera 1 prototype is superior to the Camera 2 prototype and can potentially be applied to the evaluation of nutrient status in apple leaves.
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Affiliation(s)
- Xujun Ye
- Faculty of Agriculture and Life Science, Hirosaki University, Aomori 036-8561, Japan
| | - Marin Kitaya
- Faculty of Agriculture and Life Science, Hirosaki University, Aomori 036-8561, Japan
| | - Shiori Abe
- Faculty of Agriculture and Life Science, Hirosaki University, Aomori 036-8561, Japan
| | - Fanxing Sheng
- Faculty of Agriculture and Life Science, Hirosaki University, Aomori 036-8561, Japan
| | - Shuhuai Zhang
- Faculty of Agriculture and Life Science, Hirosaki University, Aomori 036-8561, Japan
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Lee G, Hossain O, Jamalzadegan S, Liu Y, Wang H, Saville AC, Shymanovich T, Paul R, Rotenberg D, Whitfield AE, Ristaino JB, Zhu Y, Wei Q. Abaxial leaf surface-mounted multimodal wearable sensor for continuous plant physiology monitoring. SCIENCE ADVANCES 2023; 9:eade2232. [PMID: 37043563 PMCID: PMC10096584 DOI: 10.1126/sciadv.ade2232] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 03/16/2023] [Indexed: 06/19/2023]
Abstract
Wearable plant sensors hold tremendous potential for smart agriculture. We report a lower leaf surface-attached multimodal wearable sensor for continuous monitoring of plant physiology by tracking both biochemical and biophysical signals of the plant and its microenvironment. Sensors for detecting volatile organic compounds (VOCs), temperature, and humidity are integrated into a single platform. The abaxial leaf attachment position is selected on the basis of the stomata density to improve the sensor signal strength. This versatile platform enables various stress monitoring applications, ranging from tracking plant water loss to early detection of plant pathogens. A machine learning model was also developed to analyze multichannel sensor data for quantitative detection of tomato spotted wilt virus as early as 4 days after inoculation. The model also evaluates different sensor combinations for early disease detection and predicts that minimally three sensors are required including the VOC sensors.
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Affiliation(s)
- Giwon Lee
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
- Department of Chemical Engineering, Kwangwoon University, Seoul 01897, Republic of Korea
| | - Oindrila Hossain
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Sina Jamalzadegan
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Yuxuan Liu
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Hongyu Wang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Amanda C. Saville
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
| | - Tatsiana Shymanovich
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
| | - Rajesh Paul
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Dorith Rotenberg
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
- Emerging Plant Disease and Global Food Security Cluster, North Carolina State University, Raleigh, NC 27695, USA
| | - Anna E. Whitfield
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
- Emerging Plant Disease and Global Food Security Cluster, North Carolina State University, Raleigh, NC 27695, USA
| | - Jean B. Ristaino
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
- Emerging Plant Disease and Global Food Security Cluster, North Carolina State University, Raleigh, NC 27695, USA
| | - Yong Zhu
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Qingshan Wei
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
- Emerging Plant Disease and Global Food Security Cluster, North Carolina State University, Raleigh, NC 27695, USA
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Horel Á, Zsigmond T. Plant Growth and Soil Water Content Changes under Different Inter-Row Soil Management Methods in a Sloping Vineyard. PLANTS (BASEL, SWITZERLAND) 2023; 12:1549. [PMID: 37050175 PMCID: PMC10096666 DOI: 10.3390/plants12071549] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/23/2023] [Accepted: 04/01/2023] [Indexed: 06/19/2023]
Abstract
The main objective of this study was to investigate soil-plant-water interactions based on field measurements of plant reflectance and soil water content (SWC) in different inter-row managed sloping vineyards. The following three different soil management applications were studied: tilled (T), cover crops (CC), and permanent grass (NT) inter-rows. We measured SWCs within the row and between rows of vines. Each investigated row utilized 7 to 10 measurement points along the slope. Topsoil SWC and temperature, leaf NDVI and chlorophyll concentrations and leaf area index (LAI) were measured every two weeks over the vegetation period (May to November) using handheld instruments. We found that management method and slope position can significantly affect the soil's physical and chemical properties, such as clay or soil organic carbon contents. Cover crops in the inter-row significantly reduced average SWC. The in-row average topsoil SWCs and temperatures were lower in all study sites compared to the values measured in between rows. Significantly higher SWCs were observed for the upper points compared to the lower ones for CC and T treatments (58.0 and 60.9%, respectively), while the opposite was noted for NT. Grassed inter-row grapevines had significantly lower leaf chlorophyll content than the other inter-row managed sites (p < 0.001). The highest average leaf chlorophyll contents were observed in the T vineyard (16.89 CCI). Based on slope positions, the most distinguishable difference was observed for the CC: 27.7% higher chlorophyll values were observed at the top of the slope compared to the grapevine leaves at the bottom of the slope (p < 0.01). The leaf NDVI values were not as profoundly influenced by slope position in the vineyard as the chlorophyll values were. For overall LAI values, the T treatment had significantly lower values compared to NT and CC (p < 0.001). Moderate correlations were observed between NDVI and LAI and soil nitrogen and carbon content. In general, we found that both inter-row management and slope position can significantly influence soil parameters and affect plant growth, and consequently can accelerate plant stress under sub-optimal environmental conditions such as prolonged drought.
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Affiliation(s)
- Ágota Horel
- Institute for Soil Sciences, Centre for Agricultural Research, Eötvös Loránd Research Network, Herman O. St. 15, 1022 Budapest, Hungary
- National Laboratory for Water Science and Water Security, Institute for Soil Sciences, Centre for Agricultural Research, Herman O. St. 15, 1022 Budapest, Hungary
| | - Tibor Zsigmond
- Institute for Soil Sciences, Centre for Agricultural Research, Eötvös Loránd Research Network, Herman O. St. 15, 1022 Budapest, Hungary
- National Laboratory for Water Science and Water Security, Institute for Soil Sciences, Centre for Agricultural Research, Herman O. St. 15, 1022 Budapest, Hungary
- Doctoral School of Environmental Sciences, ELTE Eötvös Loránd University, Egyetem Square 1-3, 1053 Budapest, Hungary
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8
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Kamarianakis Z, Panagiotakis S. Design and Implementation of a Low-Cost Chlorophyll Content Meter. SENSORS (BASEL, SWITZERLAND) 2023; 23:2699. [PMID: 36904902 PMCID: PMC10007049 DOI: 10.3390/s23052699] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Chlorophyll meters are portable devices used to assess and improve plants' nitrogen management and to help farmers in the determination of the health condition of plants through leaf greenness measurements. These optical electronic instruments can provide an assessment of chlorophyll content by measuring the light passing through a leaf or by measuring the light radiation reflected from its surface. However, independently of the main principle of operation and use (e.g., absorbance vs. reflectance measurements), commercial chlorophyll meters usually cost hundreds or even thousands of euros, making them inaccessible to growers and ordinary citizens who are interested in self-cultivation, farmers, crop researchers, and communities lacking resources in general. A low-cost chlorophyll meter based on light-to-voltage measurements of the remaining light after two LED light emissions through a leaf is designed, constructed, evaluated, and compared against two well-known commercial chlorophyll meters, the SPAD-502 and the atLeaf CHL Plus. Initial tests of the proposed device on lemon tree leaves and on young Brussels sprouts plant leaves revealed promising results compared to the commercial instruments. The coefficient of determination, R2, was estimated to be 0.9767 for the SPAD-502 and 0.9898 for the atLeaf-meter in lemon tree leaves samples compared to the proposed device, while for the Brussels sprouts plant, R2 was estimated to be 0.9506 and 0.9624, respectively. Further tests conducted as a preliminary evaluation of the proposed device are also presented.
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Affiliation(s)
- Zacharias Kamarianakis
- Department of Electrical & Computer Engineering, Hellenic Mediterranean University, 71410 Heraklion, Greece
- Institute of Agri-Food and Life Sciences, University Research Center, Hellenic Mediterranean University, 71410 Heraklion, Greece
| | - Spyros Panagiotakis
- Department of Electrical & Computer Engineering, Hellenic Mediterranean University, 71410 Heraklion, Greece
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9
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Park B, Kang H, Han S, Kim HU, Cho Y, Huh YS, Kang SM. The Fabrication of Cesium Lead Bromide-Coated Cellulose Nanocomposites and Their Effect on the Detection of Nitrogen Gas. SENSORS (BASEL, SWITZERLAND) 2022; 22:7737. [PMID: 36298086 PMCID: PMC9611072 DOI: 10.3390/s22207737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/04/2022] [Accepted: 10/09/2022] [Indexed: 06/16/2023]
Abstract
In this work, we fabricate cesium lead bromide nanofibers (CsPbBr3 NFs) via the attachment of cesium lead bromide nanocrystals (CsPbBr3 NCs) on the surface of electrospun cellulose nanofibers (CNFs) and employ them in a sensor to effectively detect gaseous nitrogen. The CsPbBr3 NFs are produced initially by producing CsPbBr3 NCs through hot injection and dispersing on hexane, followed by dipping CNFs and ultrasonicate for 1 h. Morphological characterization through visual, SEM and TEM image, and crystalline structure analysis by XRD and FT-IR analysis of CsPbBr3 NFs and NCs show similar spectra except for PL due to unavoidable damage during the ultrasonication. Gaseous nitrogen is subsequently detected using the photoluminescence (PL) property of CsPbBr3 NFs, in which the PL intensity dramatically decreases under various flow rate. Therefore, we believe that the proposed CsPbBr3 NFs show significant promise for use in detection sensors in various industrial field and decrease the potential of fatal damage to workers due to suffocation.
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Affiliation(s)
- Bumjun Park
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Korea
| | - Haneul Kang
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Korea
| | - Soobin Han
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Korea
| | - Hyeong-U Kim
- Department of Plasma Engineering, Korea Institute of Machinery & Materials, Daejeon 34103, Korea
| | - Youngjin Cho
- Food Safety and Distribution Research Group, Korea Food Research Institute, 245 Nongsaengmyeong-ro, Iseo-myeon, Wanju-gun 55365, Jeollabuk-do, Korea
| | - Yun Suk Huh
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Korea
| | - Sung-Min Kang
- Department of Green Chemical Engineering, Sangmyung University, 31 Sangmyungdae-gil, Cheonan 31066, Chungcheongnam-do, Korea
- Future Environment and Energy Research Institute, Sangmyung University, 31 Sangmyungdae-gil, Cheonan 31066, Chungcheongnam-do, Korea
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10
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Ji R, Shi W, Wang Y, Zhang H, Min J. Development of a sensor-based site-specific N topdressing algorithm for a typical leafy vegetable. FRONTIERS IN PLANT SCIENCE 2022; 13:951181. [PMID: 36119588 PMCID: PMC9479683 DOI: 10.3389/fpls.2022.951181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
Precise and site-specific nitrogen (N) fertilizer management of vegetables is essential to improve the N use efficiency considering temporal and spatial fertility variations among fields, while the current N fertilizer recommendation methods are proved to be time- and labor-consuming. To establish a site-specific N topdressing algorithm for bok choy (Brassica rapa subsp. chinensis), using a hand-held GreenSeeker canopy sensor, we conducted field experiments in the years 2014, 2017, and 2020. Two planting densities, viz, high (123,000 plants ha-1) in Year I and low (57,000 plants ha-1) in Year II, whereas, combined densities in Year III were used to evaluate the effect of five N application rates (0, 45, 109, 157, and 205 kg N ha-1). A robust relationship was observed between the sensor-based normalized difference vegetation index (NDVI), the ratio vegetation index (RVI), and the yield potential without topdressing (YP0) at the rosette stage, and 81-84% of the variability at high density and 76-79% of that at low density could be explained. By combining the densities and years, the R 2 value increased to 0.90. Additionally, the rosette stage was identified as the earliest stage for reliably predicting the response index at harvest (RIHarvest), based on the response index derived from NDVI (RINDVI) and RVI (RIRVI), with R 2 values of 0.59-0.67 at high density and 0.53-0.65 at low density. When using the combined results, the RIRVI performed 6.12% better than the RINDVI, and 52% of the variability could be explained. This study demonstrates the good potential of establishing a sensor-based N topdressing algorithm for bok choy, which could contribute to the sustainable development of vegetable production.
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Affiliation(s)
- Rongting Ji
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of the People’s Republic of China, Nanjing, China
| | - Weiming Shi
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Yuan Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Hailin Zhang
- Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, United States
| | - Ju Min
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
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11
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Ibrahim H, Yin S, Moru S, Zhu Y, Castellano MJ, Dong L. In Planta Nitrate Sensor Using a Photosensitive Epoxy Bioresin. ACS APPLIED MATERIALS & INTERFACES 2022; 14:25949-25961. [PMID: 35638646 DOI: 10.1021/acsami.2c01988] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nitrogen management through monitoring of crop nitrate status can improve agricultural productivity, profitability, and environmental performance. Current plant nitrate test methods require expensive instruments, time-intensive labor, and trained personnel. Frequent monitoring of in planta nitrate levels of the stalks in living plants can help to better understand the nitrogen cycle and the physiological responses to environmental variations. Although existing enzymatic electrochemical sensors provide high selectivity, they suffer from short shelf life, high cost, low-temperature storage requirement, and potential degradation over time. To overcome these issues, an artificial enzyme (vitamin B12 or VB12) and a two-dimensional material (graphene oxide or GO) are introduced into a conventional photoresist (SU8) to form a bioresin SU8-GO-VB12 that can be patterned with photolithography and laser-pyrolyzed into a carbon-based nanocomposite C-GO-VB12. The electrocatalytic activity of the cobalt factor in VB12, the surface enhancement properties of GO, and the porous feature of pyrolytic carbon are synergized through design to provide C-GO-VB12 with a superior ability to detect nitrate ions through redox reactions. In addition, laser writing-based selective pyrolysis allows applying thermal energy to target only SU8-GO-VB12 for selective pyrolysis of the bioresin into C-GO-VB12, thus reducing the total energy input and avoiding the thermal influence on the materials and structures in other areas of the substrate. The C-GO-VB12 nitrate sensor demonstrates a year-long shelf lifetime, high selectivity, and a wide dynamic range that enables a direct nitrate test for the extracted sap of maize stalk. For in situ monitoring of the nitrate level and dynamic changes in living maize plants, a microelectromechanical system-based needle sensor is formed with C-GO-VB12. The needle sensor allows direct insertion into the plant for in situ measurement of nitrate ions under different growth environments over time. The needle sensor represents a new method for monitoring in planta nitrate dynamics with no need for sample preparation, thus making a significant impact in plant sciences.
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Affiliation(s)
- Hussam Ibrahim
- Department of Electrical & Computer Engineering, Iowa State University, Ames, Iowa 50011, United States
- Microelectronics Research Center, Iowa State University, Ames, Iowa 50011, United States
| | - Shihao Yin
- Department of Electrical & Computer Engineering, Iowa State University, Ames, Iowa 50011, United States
- Microelectronics Research Center, Iowa State University, Ames, Iowa 50011, United States
| | - Satyanarayana Moru
- Department of Electrical & Computer Engineering, Iowa State University, Ames, Iowa 50011, United States
| | - Yunjiao Zhu
- Agronomy Department, Iowa State University, Ames, Iowa 50011, United States
| | | | - Liang Dong
- Department of Electrical & Computer Engineering, Iowa State University, Ames, Iowa 50011, United States
- Microelectronics Research Center, Iowa State University, Ames, Iowa 50011, United States
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12
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Investigating Plant Response to Soil Characteristics and Slope Positions in a Small Catchment. LAND 2022. [DOI: 10.3390/land11060774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Methods enabling stakeholders to receive information on plant stress in agricultural settings in a timely manner can help mitigate a possible decrease in plant productivity. The present work aims to study the soil–plant interaction using field measurements of plant reflectance, soil water content, and selected soil physical and chemical parameters. Particular emphasis was placed on sloping transects. We further compared ground- and Sentinel-2 satellite-based Normalized Vegetation Index (NDVI) time series data in different land use types. The Photochemical Reflectance Index (PRI) and NDVI were measured concurrently with calculating the fraction of absorbed photochemically active radiation (fAPAR) and leaf area index (LAI) values of three vegetation types (a grassland, three vineyard sites, and a cropland with maize). Each land use site had an upper and a lower study point of a given slope. The NDVI, fAPAR, and LAI averaged values were the lowest for the grassland (0.293, 0.197, and 0.51, respectively), which showed the highest signs of water stress. Maize had the highest NDVI values (0.653) among vegetation types. Slope position affected NDVI, PRI, and fAPAR values significantly for the grassland and cropland (p < 0.05), while the soil water content (SWC) was different for all three vineyard sites (p < 0.05). The strongest connections were observed between soil physical and chemical parameters and NDVI values for the vineyard samples and the selected soil parameters and PRI for the grassland. Measured and satellite-retrieved NDVI values of the different land use types were compared, and strong correlations (r = 0.761) between the methods were found. For the maize, the satellite-based NDVI values were higher, while for the grassland they were slightly lower compared to the field-based measurements. Our study indicated that incorporating Sentinel-derived NDVI can greatly improve the value of field monitoring and provides an opportunity to extend field research in more depth. The present study further highlights the close relations in the soil–plant–water system, and continuous monitoring can greatly help in developing site-specific climate change mitigating methods.
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13
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The Self-Supervised Spectral–Spatial Vision Transformer Network for Accurate Prediction of Wheat Nitrogen Status from UAV Imagery. REMOTE SENSING 2022. [DOI: 10.3390/rs14061400] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Nitrogen (N) fertilizer is routinely applied by farmers to increase crop yields. At present, farmers often over-apply N fertilizer in some locations or at certain times because they do not have high-resolution crop N status data. N-use efficiency can be low, with the remaining N lost to the environment, resulting in higher production costs and environmental pollution. Accurate and timely estimation of N status in crops is crucial to improving cropping systems’ economic and environmental sustainability. Destructive approaches based on plant tissue analysis are time consuming and impractical over large fields. Recent advances in remote sensing and deep learning have shown promise in addressing the aforementioned challenges in a non-destructive way. In this work, we propose a novel deep learning framework: a self-supervised spectral–spatial attention-based vision transformer (SSVT). The proposed SSVT introduces a Spectral Attention Block (SAB) and a Spatial Interaction Block (SIB), which allows for simultaneous learning of both spatial and spectral features from UAV digital aerial imagery, for accurate N status prediction in wheat fields. Moreover, the proposed framework introduces local-to-global self-supervised learning to help train the model from unlabelled data. The proposed SSVT has been compared with five state-of-the-art models including: ResNet, RegNet, EfficientNet, EfficientNetV2, and the original vision transformer on both testing and independent datasets. The proposed approach achieved high accuracy (0.96) with good generalizability and reproducibility for wheat N status estimation.
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14
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Assessing Grapevine Nutrient Status from Unmanned Aerial System (UAS) Hyperspectral Imagery. REMOTE SENSING 2021. [DOI: 10.3390/rs13214489] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This study aimed to identify the optimal sets of spectral bands for monitoring multiple grapevine nutrients in vineyards. We used spectral data spanning 400–2500 nm and leaf samples from 100 Concord grapevine canopies, lab-analyzed for six key nutrient values, to select the optimal bands for the nutrient regression models. The canopy spectral data were obtained with unmanned aerial systems (UAS), using push-broom imaging spectrometers (hyperspectral sensors). The novel use of UAS-based hyperspectral imagery to assess the grapevine nutrient status fills the gap between in situ spectral sampling and UAS-based multispectral imaging, avoiding their inherent trade-offs between spatial and spectral resolution. We found that an ensemble feature ranking method, utilizing six different machine learning feature selection methods, produced similar regression results as the standard PLSR feature selection and regression while generally selecting fewer wavelengths. We identified a set of biochemically consistent bands (606, 641, and 1494 nm) to predict the nitrogen content with an RMSE of 0.17% (using leave-one-out cross-validation) in samples with nitrogen contents ranging between 2.4 and 3.6%. Further studying is needed to confirm the relevance and consistency of the wavelengths selected for each nutrient model, but ensemble feature selection showed promise in identifying stable sets of wavelengths for assessing grapevine nutrient contents from canopy spectra.
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15
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Jiang J, Wang C, Wang H, Fu Z, Cao Q, Tian Y, Zhu Y, Cao W, Liu X. Evaluation of Three Portable Optical Sensors for Non-Destructive Diagnosis of Nitrogen Status in Winter Wheat. SENSORS 2021; 21:s21165579. [PMID: 34451022 PMCID: PMC8402299 DOI: 10.3390/s21165579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 11/16/2022]
Abstract
The accurate estimation and timely diagnosis of crop nitrogen (N) status can facilitate in-season fertilizer management. In order to evaluate the performance of three leaf and canopy optical sensors in non-destructively diagnosing winter wheat N status, three experiments using seven wheat cultivars and multi-N-treatments (0–360 kg N ha−1) were conducted in the Jiangsu province of China from 2015 to 2018. Two leaf sensors (SPAD 502, Dualex 4 Scientific+) and one canopy sensor (RapidSCAN CS-45) were used to obtain leaf and canopy spectral data, respectively, during the main growth period. Five N indicators (leaf N concentration (LNC), leaf N accumulation (LNA), plant N concentration (PNC), plant N accumulation (PNA), and N nutrition index (NNI)) were measured synchronously. The relationships between the six sensor-based indices (leaf level: SPAD, Chl, Flav, NBI, canopy level: NDRE, NDVI) and five N parameters were established at each growth stages. The results showed that the Dualex-based NBI performed relatively well among four leaf-sensor indices, while NDRE of RS sensor achieved a best performance due to larger sampling area of canopy sensor for five N indicators estimation across different growth stages. The areal agreement of the NNI diagnosis models ranged from 0.54 to 0.71 for SPAD, 0.66 to 0.84 for NBI, and 0.72 to 0.86 for NDRE, and the kappa coefficient ranged from 0.30 to 0.52 for SPAD, 0.42 to 0.72 for NBI, and 0.53 to 0.75 for NDRE across all growth stages. Overall, these results reveal the potential of sensor-based diagnosis models for the rapid and non-destructive diagnosis of N status.
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Affiliation(s)
- Jie Jiang
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Cuicun Wang
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Hui Wang
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhaopeng Fu
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiang Cao
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Yongchao Tian
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Zhu
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Weixing Cao
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojun Liu
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (J.J.); (C.W.); (H.W.); (Z.F.); (Q.C.); (Y.T.); (Y.Z.); (W.C.)
- MOE Engineering Research Center of Smart Agricultural, Nanjing Agricultural University, Nanjing 210095, China
- MARA Key Laboratory for Crop System Analysis and Decision Making, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
- Correspondence: ; Tel.: +86-25-8439-6804; Fax: +86-25-8439-6672
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16
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Effect of Time of Day and Sky Conditions on Different Vegetation Indices Calculated from Active and Passive Sensors and Images Taken from UAV. REMOTE SENSING 2021. [DOI: 10.3390/rs13091691] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Optical sensors have been widely reported to be useful tools to assess biomass, nutrition, and water status in several crops. However, the use of these sensors could be affected by the time of day and sky conditions. This study aimed to evaluate the effect of time of day and sky conditions (sunny versus overcast) on several vegetation indices (VI) calculated from two active sensors (the Crop Circle ACS-470 and Greenseeker RT100), two passive sensors (the hyperspectral bidirectional passive spectrometer and HandySpec Field sensor), and images taken from an unmanned aerial vehicle (UAV). The experimental work was conducted in a wheat crop in south-west Germany, with eight nitrogen (N) application treatments. Optical sensor measurements were made throughout the vegetative growth period on different dates in 2019 at 9:00, 14:00, and 16:00 solar time to evaluate the effect of time of day, and on a sunny and overcast day only at 9:00 h to evaluate the influence of sky conditions on different vegetation indices. For most vegetation indices evaluated, there were significant differences between paired time measurements, regardless of the sensor and day of measurement. The smallest differences between measurement times were found between measurements at 14:00 and 16:00 h, and they were observed for the vehicle-carried and the handheld hyperspectral passive sensor being lower than 2% and 4%, respectively, for the indices NIR/Red edge ratio, Red edge inflection point (REIP), and the water index. Differences were lower than 5% for the vehicle-carried active sensors Crop Circle ACS-470 (indices NIR/Red edge and NIR/Red ratios, and NDVI) and Greenseeker RT100 (index NDVI). The most stable indices over measurement times were the NIR/Red edge ratio, water index, and REIP index, regardless of the sensor used. The most considerable differences between measurement times were found for the simple ratios NIR/Red and NIR/Green. For measurements made on a sunny and overcast day, the most stable were the indices NIR/Red edge ratio, water index, and REIP. In practical terms, these results confirm that passive and active sensors could be used to measure on-farm at any time of day from 9:00 to 16:00 h by choosing optimized indices.
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Kaniszewski S, Kowalski A, Dysko J, Agati G. Application of a Combined Transmittance/Fluorescence Leaf Clip Sensor for the Nondestructive Determination of Nitrogen Status in White Cabbage Plants. SENSORS 2021; 21:s21020482. [PMID: 33445510 PMCID: PMC7827347 DOI: 10.3390/s21020482] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/28/2020] [Accepted: 01/08/2021] [Indexed: 11/16/2022]
Abstract
The correct fertilization of vegetable crops is commonly determined on the basis of soil and plant costly destructive analyses, demanding more sustainable non-invasive optical detection. Here, we tested the ability of the combined transmittance/fluorescence leaf clip Dualex device for determining the nitrogen (N) status of cabbage plants. Fully developed leaves from plants grown under different N rates of 0; 100; 200; 300 kg N ha−1 in 2018 and 2019 were measured in the field by the Dualex sensor twice a year in July and October. The chlorophyll (Chl) and nitrogen (nitrogen balance index, NBI) indices and the flavonols (Flav) index of the sensor were positively and negatively correlated to leaf nitrogen, respectively. Merging the two-years data, the NBI versus leaf N correlation was less point dispersed in October than July (R2 = 0.76 and 0.64, respectively). NBI was also correlated to cabbage yield, better in July than October. Our results showed that the multiparametric Dualex device can be used as precision agriculture tool for the early prediction of plant N and cabbage yield with economic advantage for the growers and reduced environmental contamination due to nitrate leaching.
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Affiliation(s)
- Stanisław Kaniszewski
- Research Institute of Horticulture, Konstytucji 3Maja 1/3, 96-100 Skierniewice, Poland; (S.K.); (A.K.); (J.D.)
| | - Artur Kowalski
- Research Institute of Horticulture, Konstytucji 3Maja 1/3, 96-100 Skierniewice, Poland; (S.K.); (A.K.); (J.D.)
| | - Jacek Dysko
- Research Institute of Horticulture, Konstytucji 3Maja 1/3, 96-100 Skierniewice, Poland; (S.K.); (A.K.); (J.D.)
| | - Giovanni Agati
- Istituto di Fisica Applicata “Nello Carrara”-CNR, Via Madonna del Piano, 10-50019 Sesto Fiorentino (FI), Italy
- Correspondence: ; Tel.: +39-055-5225-306
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18
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Management of Fertigation in Horticultural Crops through Automation with Electrotensiometers: Effect on the Productivity of Water and Nutrients. SENSORS 2020; 21:s21010190. [PMID: 33396728 PMCID: PMC7796250 DOI: 10.3390/s21010190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 12/24/2020] [Accepted: 12/25/2020] [Indexed: 11/29/2022]
Abstract
Water and nutrient requirements of horticultural crops are influenced by different factors such as: Type of crop, stage of development and production system. Although greenhouse horticultural crops are more efficient in the use of water and fertilizers compared to other production systems, it is necessary increase efficiency for which individualized fertigation strategies must be designed for each greenhouse. The automation of fertigation based on the level of soil moisture allows optimization of management. The objective of this work was to determine the influence of the activation command of fertigation with electrotensiometers and the characteristics of the greenhouse on the productivity of the crop and the efficiency of use of water and nutrients in a sweet pepper crop. The trial was developed in two greenhouses. Four treatments were studied, combination of who two-factor: Soil matric potential (SMP) (SMP−10: Automatic activation of irrigation to −10 kPa and SMP−20: Automatic activation of irrigation to −20 kPa) and greenhouse characteristics (G1 and G2). The nutritive solution applied was the same in all treatments. The yield and volume of water and nutrients applied were determined, calculating the productivity of the water (WP), as well as productivity the nutrients. The fertigation activation threshold of −10 kPa presented the best results, increasing the yield and conserving WP and nutrient productivity with respect to −20 kPa in both greenhouses. The automation of irrigation with electrotensiometers allowed the application of different volume of fertigation demanded by the crop in each greenhouse, equalizing the WP and nutrient productivity without producing drainage. The pepper crop in the greenhouse G1 presented greater vegetative development, higher yield and demanded a greater volume of fertigation than G2 regardless of the activation threshold. This was due to the fact that the soil matric potential after irrigation in greenhouse G1 was closer to zero, being able to conclude that not only the soil matric potential threshold of irrigation activation has an influence on crop, but also the potential registered after irrigation. Soil matric potentials closer to zero are more productive.
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19
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Mittal D, Kaur G, Singh P, Yadav K, Ali SA. Nanoparticle-Based Sustainable Agriculture and Food Science: Recent Advances and Future Outlook. FRONTIERS IN NANOTECHNOLOGY 2020. [DOI: 10.3389/fnano.2020.579954] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
In the current scenario, it is an urgent requirement to satisfy the nutritional demands of the rapidly growing global population. Using conventional farming, nearly one third of crops get damaged, mainly due to pest infestation, microbial attacks, natural disasters, poor soil quality, and lesser nutrient availability. More innovative technologies are immediately required to overcome these issues. In this regard, nanotechnology has contributed to the agrotechnological revolution that has imminent potential to reform the resilient agricultural system while promising food security. Therefore, nanoparticles are becoming a new-age material to transform modern agricultural practices. The variety of nanoparticle-based formulations, including nano-sized pesticides, herbicides, fungicides, fertilizers, and sensors, have been widely investigated for plant health management and soil improvement. In-depth understanding of plant and nanomaterial interactions opens new avenues toward improving crop practices through increased properties such as disease resistance, crop yield, and nutrient utilization. In this review, we highlight the critical points to address current nanotechnology-based agricultural research that could benefit productivity and food security in future.
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Yi J, Krusenbaum L, Unger P, Hüging H, Seidel SJ, Schaaf G, Gall J. Deep Learning for Non-Invasive Diagnosis of Nutrient Deficiencies in Sugar Beet Using RGB Images. SENSORS (BASEL, SWITZERLAND) 2020; 20:E5893. [PMID: 33080979 PMCID: PMC7589690 DOI: 10.3390/s20205893] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 11/16/2022]
Abstract
In order to enable timely actions to prevent major losses of crops caused by lack of nutrients and, hence, increase the potential yield throughout the growing season while at the same time prevent excess fertilization with detrimental environmental consequences, early, non-invasive, and on-site detection of nutrient deficiency is required. Current non-invasive methods for assessing the nutrient status of crops deal in most cases with nitrogen (N) deficiency only and optical sensors to diagnose N deficiency, such as chlorophyll meters or canopy reflectance sensors, do not monitor N, but instead measure changes in leaf spectral properties that may or may not be caused by N deficiency. In this work, we study how well nutrient deficiency symptoms can be recognized in RGB images of sugar beets. To this end, we collected the Deep Nutrient Deficiency for Sugar Beet (DND-SB) dataset, which contains 5648 images of sugar beets growing on a long-term fertilizer experiment with nutrient deficiency plots comprising N, phosphorous (P), and potassium (K) deficiency, as well as the omission of liming (Ca), full fertilization, and no fertilization at all. We use the dataset to analyse the performance of five convolutional neural networks for recognizing nutrient deficiency symptoms and discuss their limitations.
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Affiliation(s)
- Jinhui Yi
- Computer Vision Group, Institute of Computer Science III, University of Bonn, Endenicher Allee 19a, 53115 Bonn, Germany;
| | - Lukas Krusenbaum
- Plant Nutrition Group, Institute of Crop Science and Resource Conservation, University of Bonn, Karlrobert-Kreiten-Strasse 13, 53115 Bonn, Germany; (L.K.); (P.U.); (G.S.)
| | - Paula Unger
- Plant Nutrition Group, Institute of Crop Science and Resource Conservation, University of Bonn, Karlrobert-Kreiten-Strasse 13, 53115 Bonn, Germany; (L.K.); (P.U.); (G.S.)
| | - Hubert Hüging
- Crop Science Group, Institute of Crop Science and Resource Conservation, University of Bonn, Katzenburgweg 5, 53115 Bonn, Germany; (H.H.); (S.J.S.)
| | - Sabine J. Seidel
- Crop Science Group, Institute of Crop Science and Resource Conservation, University of Bonn, Katzenburgweg 5, 53115 Bonn, Germany; (H.H.); (S.J.S.)
| | - Gabriel Schaaf
- Plant Nutrition Group, Institute of Crop Science and Resource Conservation, University of Bonn, Karlrobert-Kreiten-Strasse 13, 53115 Bonn, Germany; (L.K.); (P.U.); (G.S.)
| | - Juergen Gall
- Computer Vision Group, Institute of Computer Science III, University of Bonn, Endenicher Allee 19a, 53115 Bonn, Germany;
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21
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Berger K, Verrelst J, Féret JB, Hank T, Wocher M, Mauser W, Camps-Valls G. Retrieval of aboveground crop nitrogen content with a hybrid machine learning method. INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION : ITC JOURNAL 2020; 92:102174. [PMID: 36090128 PMCID: PMC7613569 DOI: 10.1016/j.jag.2020.102174] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Hyperspectral acquisitions have proven to be the most informative Earth observation data source for the estimation of nitrogen (N) content, which is the main limiting nutrient for plant growth and thus agricultural production. In the past, empirical algorithms have been widely employed to retrieve information on this biochemical plant component from canopy reflectance. However, these approaches do not seek for a cause-effect relationship based on physical laws. Moreover, most studies solely relied on the correlation of chlorophyll content with nitrogen, and thus neglected the fact that most N is bound in proteins. Our study presents a hybrid retrieval method using a physically-based approach combined with machine learning regression to estimate crop N content. Within the workflow, the leaf optical properties model PROSPECT-PRO including the newly calibrated specific absorption coefficients (SAC) of proteins, was coupled with the canopy reflectance model 4SAIL to PROSAIL-PRO. The latter was then employed to generate a training database to be used for advanced probabilistic machine learning methods: a standard homoscedastic Gaussian process (GP) and a heteroscedastic GP regression that accounts for signal-to-noise relations. Both GP models have the property of providing confidence intervals for the estimates, which sets them apart from other machine learners. Moreover, a GP-based sequential backward band removal algorithm was employed to analyze the band-specific information content of PROSAIL-PRO simulated spectra for the estimation of aboveground N. Data from multiple hyperspectral field campaigns, carried out in the framework of the future satellite mission Environmental Mapping and Analysis Program (EnMAP), were exploited for validation. In these campaigns, corn and winter wheat spectra were acquired to simulate spectral EnMAP data. Moreover, destructive N measurements from leaves, stalks and fruits were collected separately to enable plant-organ-specific validation. The results showed that both GP models can provide accurate aboveground N simulations, with slightly better results of the heteroscedastic GP in terms of model testing and against in situ N measurements from leaves plus stalks, with root mean square error (RMSE) of 2.1 g/m2. However, the inclusion of fruit N content for validation deteriorated the results, which can be explained by the inability of the radiation to penetrate the thick tissues of stalks, corn cobs and wheat ears. GP-based band analysis identified optimal spectral settings with ten bands mainly situated in the shortwave infrared (SWIR) spectral region. Use of well-known protein absorption bands from the literature showed comparative results. Finally, the heteroscedastic GP model was successfully applied on airborne hyperspectral data for N mapping. We conclude that GP algorithms, and in particular the heteroscedastic GP, should be implemented for global agricultural monitoring of aboveground N from future imaging spectroscopy data.
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Affiliation(s)
- Katja Berger
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
- Corresponding author. (K. Berger)
| | - Jochem Verrelst
- Image Processing Laboratory (IPL), Parc Científic, Universitat de València, Paterna, València, 46980, Spain
| | - Jean-Baptiste Féret
- TETIS, INRAE, AgroParisTech, CIRAD, CNRS, Université Montpellier, Montpellier, France
| | - Tobias Hank
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Matthias Wocher
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Wolfram Mauser
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Gustau Camps-Valls
- Image Processing Laboratory (IPL), Parc Científic, Universitat de València, Paterna, València, 46980, Spain
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Berger K, Verrelst J, Féret JB, Hank T, Wocher M, Mauser W, Camps-Valls G. Retrieval of aboveground crop nitrogen content with a hybrid machine learning method. INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION : ITC JOURNAL 2020; 92:102174. [PMID: 36090128 DOI: 10.1016/j.jag.2020.102177] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Hyperspectral acquisitions have proven to be the most informative Earth observation data source for the estimation of nitrogen (N) content, which is the main limiting nutrient for plant growth and thus agricultural production. In the past, empirical algorithms have been widely employed to retrieve information on this biochemical plant component from canopy reflectance. However, these approaches do not seek for a cause-effect relationship based on physical laws. Moreover, most studies solely relied on the correlation of chlorophyll content with nitrogen, and thus neglected the fact that most N is bound in proteins. Our study presents a hybrid retrieval method using a physically-based approach combined with machine learning regression to estimate crop N content. Within the workflow, the leaf optical properties model PROSPECT-PRO including the newly calibrated specific absorption coefficients (SAC) of proteins, was coupled with the canopy reflectance model 4SAIL to PROSAIL-PRO. The latter was then employed to generate a training database to be used for advanced probabilistic machine learning methods: a standard homoscedastic Gaussian process (GP) and a heteroscedastic GP regression that accounts for signal-to-noise relations. Both GP models have the property of providing confidence intervals for the estimates, which sets them apart from other machine learners. Moreover, a GP-based sequential backward band removal algorithm was employed to analyze the band-specific information content of PROSAIL-PRO simulated spectra for the estimation of aboveground N. Data from multiple hyperspectral field campaigns, carried out in the framework of the future satellite mission Environmental Mapping and Analysis Program (EnMAP), were exploited for validation. In these campaigns, corn and winter wheat spectra were acquired to simulate spectral EnMAP data. Moreover, destructive N measurements from leaves, stalks and fruits were collected separately to enable plant-organ-specific validation. The results showed that both GP models can provide accurate aboveground N simulations, with slightly better results of the heteroscedastic GP in terms of model testing and against in situ N measurements from leaves plus stalks, with root mean square error (RMSE) of 2.1 g/m2. However, the inclusion of fruit N content for validation deteriorated the results, which can be explained by the inability of the radiation to penetrate the thick tissues of stalks, corn cobs and wheat ears. GP-based band analysis identified optimal spectral settings with ten bands mainly situated in the shortwave infrared (SWIR) spectral region. Use of well-known protein absorption bands from the literature showed comparative results. Finally, the heteroscedastic GP model was successfully applied on airborne hyperspectral data for N mapping. We conclude that GP algorithms, and in particular the heteroscedastic GP, should be implemented for global agricultural monitoring of aboveground N from future imaging spectroscopy data.
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Affiliation(s)
- Katja Berger
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Jochem Verrelst
- Image Processing Laboratory (IPL), Parc Científic, Universitat de València, Paterna, València, 46980, Spain
| | - Jean-Baptiste Féret
- TETIS, INRAE, AgroParisTech, CIRAD, CNRS, Université Montpellier, Montpellier, France
| | - Tobias Hank
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Matthias Wocher
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Wolfram Mauser
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Gustau Camps-Valls
- Image Processing Laboratory (IPL), Parc Científic, Universitat de València, Paterna, València, 46980, Spain
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Berger K, Verrelst J, Féret JB, Hank T, Wocher M, Mauser W, Camps-Valls G. Retrieval of aboveground crop nitrogen content with a hybrid machine learning method. INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION : ITC JOURNAL 2020; 92:102174. [PMID: 36090128 DOI: 10.1016/j.jag.2020.102219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Hyperspectral acquisitions have proven to be the most informative Earth observation data source for the estimation of nitrogen (N) content, which is the main limiting nutrient for plant growth and thus agricultural production. In the past, empirical algorithms have been widely employed to retrieve information on this biochemical plant component from canopy reflectance. However, these approaches do not seek for a cause-effect relationship based on physical laws. Moreover, most studies solely relied on the correlation of chlorophyll content with nitrogen, and thus neglected the fact that most N is bound in proteins. Our study presents a hybrid retrieval method using a physically-based approach combined with machine learning regression to estimate crop N content. Within the workflow, the leaf optical properties model PROSPECT-PRO including the newly calibrated specific absorption coefficients (SAC) of proteins, was coupled with the canopy reflectance model 4SAIL to PROSAIL-PRO. The latter was then employed to generate a training database to be used for advanced probabilistic machine learning methods: a standard homoscedastic Gaussian process (GP) and a heteroscedastic GP regression that accounts for signal-to-noise relations. Both GP models have the property of providing confidence intervals for the estimates, which sets them apart from other machine learners. Moreover, a GP-based sequential backward band removal algorithm was employed to analyze the band-specific information content of PROSAIL-PRO simulated spectra for the estimation of aboveground N. Data from multiple hyperspectral field campaigns, carried out in the framework of the future satellite mission Environmental Mapping and Analysis Program (EnMAP), were exploited for validation. In these campaigns, corn and winter wheat spectra were acquired to simulate spectral EnMAP data. Moreover, destructive N measurements from leaves, stalks and fruits were collected separately to enable plant-organ-specific validation. The results showed that both GP models can provide accurate aboveground N simulations, with slightly better results of the heteroscedastic GP in terms of model testing and against in situ N measurements from leaves plus stalks, with root mean square error (RMSE) of 2.1 g/m2. However, the inclusion of fruit N content for validation deteriorated the results, which can be explained by the inability of the radiation to penetrate the thick tissues of stalks, corn cobs and wheat ears. GP-based band analysis identified optimal spectral settings with ten bands mainly situated in the shortwave infrared (SWIR) spectral region. Use of well-known protein absorption bands from the literature showed comparative results. Finally, the heteroscedastic GP model was successfully applied on airborne hyperspectral data for N mapping. We conclude that GP algorithms, and in particular the heteroscedastic GP, should be implemented for global agricultural monitoring of aboveground N from future imaging spectroscopy data.
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Affiliation(s)
- Katja Berger
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Jochem Verrelst
- Image Processing Laboratory (IPL), Parc Científic, Universitat de València, Paterna, València, 46980, Spain
| | - Jean-Baptiste Féret
- TETIS, INRAE, AgroParisTech, CIRAD, CNRS, Université Montpellier, Montpellier, France
| | - Tobias Hank
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Matthias Wocher
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Wolfram Mauser
- Department of Geography, Ludwig-Maximilians-Umversität Munich, Luisenstr. 37, 80333, Munich, Germany
| | - Gustau Camps-Valls
- Image Processing Laboratory (IPL), Parc Científic, Universitat de València, Paterna, València, 46980, Spain
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A Sustainability Assessment of the Greenseeker N Management Tool: A Lysimetric Experiment on Barley. SUSTAINABILITY 2020. [DOI: 10.3390/su12187303] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A preliminary study was conducted to analyze the sustainability of barley production through: (i) investigating sensor-based nitrogen (N) application on barley performance, compared with conventional N management (CT); (ii) assessing the potential of the Normalized Difference Vegetation Index (NDVI) at different growth stages for within-season predictions of crop parameters; and (iii) evaluating sensor-based fertilization benefits in the form of greenhouse gasses mitigation. Barley was grown under CT, sensor-based management (RF) and with no N fertilization (Control). NDVI measurements and RF fertilization were performed using a GreenSeeker™ 505 hand-held optical sensor. Gas emissions were measured using a static chamber method with a portable gas analyzer. Results showed that barley yield was not statistically different under RF and CF, while they both differed significantly from Control. Highly significant positive correlations were observed between NDVI and production parameters at harvesting from the middle of stem elongation to the medium milk stage across treatments. Our findings suggest that RF is able to decrease CO2 emission in comparison with CF. The relationship between N fertilization and CH4 emission showed high variability. These preliminary results provide an indication of the benefits achieved using a simple proximal sensing methodology to support N fertilization.
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Seo JS, Kim JK. Nitrogen molecular sensors and their use for screening mutants involved in nitrogen use efficiency. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 298:110587. [PMID: 32771146 DOI: 10.1016/j.plantsci.2020.110587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/22/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
Nitrogen (N) is an essential macronutrient that is required for plant growth and development and has a major impact on crop yield and biomass. However, excessive application of N-based fertilizer results in environmental pollution and increases cultivation cost. A significant target of crop biotechnology is to develop crop varieties with improved N use efficiency (NUE), thereby overcoming these issues. While various aspects of plant N uptake and utilization have been studied, many factors that fundamentally affect NUE remain uncharacterized. For example, much remains to be learnt about the genes that determine NUE. One of the significant barriers to studying NUE is the absence of an in vivo N monitoring system. There are currently several methods for measuring plant N status, but they have limitations in terms of screening for NUE mutants and sensitive NUE assessment. Here, we describe strategies for generating and screening mutant pools using N molecular sensors, comprised of the rice genes OsALN and OsUPS1, the expression of which is sensitive to endogenous N status. Forward and reverse genetic approaches using the molecular N sensors will help identify molecular mechanisms underlying NUE.
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Affiliation(s)
- Jun Sung Seo
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Ju-Kon Kim
- Crop Biotechnology Institute, GreenBio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea.
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Abstract
A crop’s health can be determined by its leaf nutrient status; more precisely, leaf nitrogen (N) level, is a critical indicator that carries a lot of worthwhile nutrient information for classifying the plant’s health. However, the existing non-invasive techniques are expensive and bulky. The aim of this study is to develop a low-cost, quick-read multi-spectral sensor array to predict N level in leaves non-invasively. The proposed sensor module has been developed using two reflectance-based multi-spectral sensors (visible and near-infrared (NIR)). In addition, the proposed device can capture the reflectance data at 12 different wavelengths (six for each sensor). We conducted the experiment on canola leaves in a controlled greenhouse environment as well as in the field. In the greenhouse experiment, spectral data were collected from 87 leaves of 24 canola plants, subjected to varying levels of N fertilization. Later, 42 canola cultivars were subjected to low and high nitrogen levels in the field experiment. The k-nearest neighbors (KNN) algorithm was employed to model the reflectance data. The trained model shows an average accuracy of 88.4% on the test set for the greenhouse experiment and 79.2% for the field experiment. Overall, the result concludes that the proposed cost-effective sensing system can be viable in determining leaf nitrogen status.
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Abstract
Nitrogen (N) splitting is critical to achieving high crop yields without having negative effects on the environment. Monitoring crop N status throughout the wheat growing season is key to finding the balance between crop N requirements and fertilizer needs. Three soft winter wheat fertilization trials under rainfed conditions in Mediterranean climate conditions were monitored with a RapidScan CS-45 (Holland Scientific, Lincoln, NE, USA) instrument to determine the normalized difference vegetation index (NDVI) values at the GS30, GS32, GS37, and GS65 growth stages. The threshold NDVI values in the Cezanne variety were 0.7–0.75 at the GS32, GS37, and GS65 growing stages. However, for the GS30 growing stage, a threshold value could not be established precisely. At this stage, N deficiency may not affect wheat yield, as long as the N status increases at GS32 stage and it is maintained thereafter. Following the NDVI dynamic throughout the growing season could help to predict the yields at harvest time. Therefore, the ΣNDVI from GS30 to GS65 explains about 80% of wheat yield variability. Therefore, a given yield could be achieved with different dynamics in wheat NDVI values throughout the growing cycle. The determined ranges of the NDVI values might be used for developing new fertilization strategies that are able to adjust N fertilization to wheat crop needs.
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28
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Recent Development and Challenges in Spectroscopy and Machine Vision Technologies for Crop Nitrogen Diagnosis: A Review. REMOTE SENSING 2020. [DOI: 10.3390/rs12162578] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recent development of non-destructive optical techniques, such as spectroscopy and machine vision technologies, have laid a good foundation for real-time monitoring and precise management of crop N status. However, their advantages and disadvantages have not been systematically summarized and evaluated. Here, we reviewed the state-of-the-art of non-destructive optical methods for monitoring the N status of crops, and summarized their advantages and disadvantages. We mainly focused on the contribution of spectral and machine vision technology to the accurate diagnosis of crop N status from three aspects: system selection, data processing, and estimation methods. Finally, we discussed the opportunities and challenges of the application of these technologies, followed by recommendations for future work to address the challenges.
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Abstract
Proximal optical sensors (POSs) are effective devices for monitoring the development of crops and the nitrogen (N) status of plants. POSs are both useful and necessary in facilitating the reduction of N losses into the environment and in attaining higher nitrogen use efficiency (NUE). To date, no comparison of these instruments has been made on quinoa. A field experiment conducted in Tuscany, Italy, with different POSs, has assessed the development of quinoa with respect to N status. Three sets of POSs were used (SPAD-502, GreenSeeker, and Canopeo App.) to monitor quinoa development and growth under different types of fertilizers (digestate and urea) and levels of N fertilization (100, 50, and 0 kg N ha−1). The present findings showed that in-season predictions of crop biomass at harvest by SPAD-502 and GreenSeeker optical sensors were successful in terms of the coefficient of determination (R2 = 0.68 and 0.82, respectively) and statistical significance (p < 0.05), while the Canopeo App. was suitable for monitoring the plant´s canopy expansion and senescence. The relative error (RE%) showed a remarkably high performance between observed and predicted values, 5.80% and 4.12% for GreenSeeker and SPAD-502, respectively. Overall, the POSs were effective devices for monitoring quinoa development during the growing season and for predicting dry biomass at harvest. However, abiotic stresses (e.g., heat-stress conditions at flowering) were shown to reduce POSs’ accuracy when estimating seed yields at harvest, and this problem will likely be overcome by advancing the sowing date.
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Berger K, Verrelst J, Féret JB, Wang Z, Wocher M, Strathmann M, Danner M, Mauser W, Hank T. Crop nitrogen monitoring: Recent progress and principal developments in the context of imaging spectroscopy missions. REMOTE SENSING OF ENVIRONMENT 2020; 242:111758. [PMID: 36082364 PMCID: PMC7613361 DOI: 10.1016/j.rse.2020.111758] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nitrogen (N) is considered as one of the most important plant macronutrients and proper management of N therefore is a pre-requisite for modern agriculture. Continuous satellite-based monitoring of this key plant trait would help to understand individual crop N use efficiency and thus would enable site-specific N management. Since hyperspectral imaging sensors could provide detailed measurements of spectral signatures corresponding to the optical activity of chemical constituents, they have a theoretical advantage over multi-spectral sensing for the detection of crop N. The current study aims to provide a state-of-the-art overview of crop N retrieval methods from hyperspectral data in the agricultural sector and in the context of future satellite imaging spectroscopy missions. Over 400 studies were reviewed for this purpose, identifying those estimating mass-based N (N concentration, N%) and area-based N (N content, Narea) using hyperspectral remote sensing data. Retrieval methods of the 125 studies selected in this review can be grouped into: (1) parametric regression methods, (2) linear nonparametric regression methods or chemometrics, (3) nonlinear nonparametric regression methods or machine learning regression algorithms, (4) physically-based or radiative transfer models (RTM), (5) use of alternative data sources (sun-induced fluorescence, SIF) and (6) hybrid or combined techniques. Whereas in the last decades methods for estimation of Narea and N% from hyperspectral data have been mainly based on simple parametric regression algorithms, such as narrowband vegetation indices, there is an increasing trend of using machine learning, RTM and hybrid techniques. Within plants, N is invested in proteins and chlorophylls stored in the leaf cells, with the proteins being the major nitrogen-containing biochemical constituent. However, in most studies, the relationship between N and chlorophyll content was used to estimate crop N, focusing on the visible-near infrared (VNIR) spectral domains, and thus neglecting protein-related N and reallocation of nitrogen to non-photosynthetic compartments. Therefore, we recommend exploiting the estimation of nitrogen via the proxy of proteins using hyperspectral data and in particular the short-wave infrared (SWIR) spectral domain. We further strongly encourage a standardization of nitrogen terminology, distinguishing between N% and Narea. Moreover, the exploitation of physically-based approaches is highly recommended combined with machine learning regression algorithms, which represents an interesting perspective for future research in view of new spaceborne imaging spectroscopy sensors.
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Affiliation(s)
- Katja Berger
- Department of Geography, Ludwig-Maximilians-Universitaet München, Luisenstr 37, 80333 Munich, Germany
- Corresponding author. (K. Berger)
| | - Jochem Verrelst
- Image Processing Laboratory (IPL), Parc Científic, Universitat de València, Paterna, València 46980, Spain
| | - Jean-Baptiste Féret
- TETIS, INRAE, AgroParisTech, CIRAD, CNRS, Université Montpellier, Montpellier, France
| | - Zhihui Wang
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706, USA
| | - Matthias Wocher
- Department of Geography, Ludwig-Maximilians-Universitaet München, Luisenstr 37, 80333 Munich, Germany
| | - Markus Strathmann
- Department of Geography, Ludwig-Maximilians-Universitaet München, Luisenstr 37, 80333 Munich, Germany
| | - Martin Danner
- Department of Geography, Ludwig-Maximilians-Universitaet München, Luisenstr 37, 80333 Munich, Germany
| | - Wolfram Mauser
- Department of Geography, Ludwig-Maximilians-Universitaet München, Luisenstr 37, 80333 Munich, Germany
| | - Tobias Hank
- Department of Geography, Ludwig-Maximilians-Universitaet München, Luisenstr 37, 80333 Munich, Germany
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Transforming Unmanned Aerial Vehicle (UAV) and Multispectral Sensor into a Practical Decision Support System for Precision Nitrogen Management in Corn. REMOTE SENSING 2020. [DOI: 10.3390/rs12101597] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Determining the optimal nitrogen (N) rate in corn remains a critical issue, mainly due to unaccounted spatial (e.g., soil properties) and temporal (e.g., weather) variability. Unmanned aerial vehicles (UAVs) equipped with multispectral sensors may provide opportunities to improve N management by the timely informing of spatially variable, in-season N applications. Here, we developed a practical decision support system (DSS) to translate spatial field characteristics and normalized difference red edge (NDRE) values into an in-season N application recommendation. On-farm strip-trials were established at three sites over two years to compare farmer’s traditional N management to a split-application N management guided by our UAV sensor-based DSS. The proposed systems increased nitrogen use efficiency 18.3 ± 6.1 kg grain kg N−1 by reducing N rates by 31 ± 6.3 kg N ha−1 with no yield differences compared to the farmers’ traditional management. We identify five avenues for further improvement of the proposed DSS: definition of the initial base N rate, estimation of inputs for sensor algorithms, management zone delineation, high-resolution image normalization approach, and the threshold for triggering N application. Two virtual reference (VR) methods were compared with the high N (HN) reference strip method for normalizing high-resolution sensor data. The VR methods resulted in significantly lower sufficiency index values than those generated by the HN reference, resulting in N fertilization recommendations that were 31.4 ± 10.3 kg ha−1 higher than the HN reference N fertilization recommendation. The use of small HN reference blocks in contrasting management zones may be more appropriate to translate field-scale, high-resolution imagery into in-season N recommendations. In view of a growing interest in using UAVs in commercial fields and the need to improve crop NUE, further work is needed to refine approaches for translating imagery into in-season N recommendations.
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32
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Saleem M, Atta BM, Ali Z, Bilal M. Laser-induced fluorescence spectroscopy for early disease detection in grapefruit plants. Photochem Photobiol Sci 2020; 19:713-721. [PMID: 32338657 DOI: 10.1039/c9pp00368a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biotic and abiotic stress both cause a considerable decrease in the chlorophyll content in plant leaves, which provides a means for the early diagnosis of diseases in plants. The emergence of diseases affects the fluorescence of phenolic compounds and chlorophyll, which have emissions located at 530, 686 and 735 nm. Herein, it was found that the intensity of the emission band of phenolic compounds at 530 nm increased and that of chlorophyll at 735 nm decreased with the onset of diseases. Statistical analysis through principal component analysis (PCA) and partial least squares regression (PLSR) was performed, which differentiated between apparently healthy leaf sites and diseased leaves, providing a basis for the detection of diseases in the early stages. The PLSR model was validated through the coefficient of determination (R2), standard error of prediction (SEP) and standard error of calibration (SEC) with the values of 0.99, 0.394 and 0.0.401, respectively, which authenticated the model. The prediction accuracy of the model was evaluated through root mean square error in prediction (RMSEP), with a value of 0.14, by predicting 22 unknown emission spectra of different leaf sites. Both the PCA and PLSR models produced similar results, proving that fluorescence spectroscopy is an excellent tool for early disease detection in plants.
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Affiliation(s)
- M Saleem
- Agri. & Biophotonics Division, National Institute of Lasers and Optronics College, Pakistan Institute of Engineering and Applied Sciences (NILOP-C, PIEAS), 45650, Nilore, Islamabad, Pakistan.
| | - Babar Manzoor Atta
- Agri. & Biophotonics Division, National Institute of Lasers and Optronics College, Pakistan Institute of Engineering and Applied Sciences (NILOP-C, PIEAS), 45650, Nilore, Islamabad, Pakistan
| | - Zulfiqar Ali
- Agri. & Biophotonics Division, National Institute of Lasers and Optronics College, Pakistan Institute of Engineering and Applied Sciences (NILOP-C, PIEAS), 45650, Nilore, Islamabad, Pakistan
| | - M Bilal
- Agri. & Biophotonics Division, National Institute of Lasers and Optronics College, Pakistan Institute of Engineering and Applied Sciences (NILOP-C, PIEAS), 45650, Nilore, Islamabad, Pakistan
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33
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Estimating Plant Nitrogen Concentration of Maize Using a Leaf Fluorescence Sensor across Growth Stages. REMOTE SENSING 2020. [DOI: 10.3390/rs12071139] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Nitrogen (N) is one of the most essential nutrients that can significantly affect crop grain yield and quality. The implementation of proximal and remote sensing technologies in precision agriculture has provided new opportunities for non-destructive and real-time diagnosis of crop N status and precision N management. Notably, leaf fluorescence sensors have shown high potential in the accurate estimation of plant N status. However, most studies using leaf fluorescence sensors have mainly focused on the estimation of leaf N concentration (LNC) rather than plant N concentration (PNC). The objectives of this study were to (1) determine the relationship of maize (Zea mays L.) LNC and PNC, (2) evaluate the main factors influencing the variations of leaf fluorescence sensor parameters, and (3) establish a general model to estimate PNC directly across growth stages. A leaf fluorescence sensor, Dualex 4, was used to test maize leaves with three different positions across four growth stages in two fields with different soil types, planting densities, and N application rates in Northeast China in 2016 and 2017. The results indicated that the total leaf N concentration (TLNC) and PNC had a strong correlation (R2 = 0.91 to 0.98) with the single leaf N concentration (SLNC). The TLNC and PNC were affected by maize growth stage and N application rate but not the soil type. When used in combination with the days after sowing (DAS) parameter, modified Dualex 4 indices showed strong relationships with TLNC and PNC across growth stages. Both modified chlorophyll concentration (mChl) and modified N balance index (mNBI) were reliable predictors of PNC. Good results could be achieved by using information obtained only from the newly fully expanded leaves before the tasseling stage (VT) and the leaves above panicle at the VT stage to estimate PNC. It is concluded that when used together with DAS, the leaf fluorescence sensor (Dualex 4) can be used to reliably estimate maize PNC across growth stages.
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Jiang J, Wang C, Wang Y, Cao Q, Tian Y, Zhu Y, Cao W, Liu X. Using an Active Sensor to Develop New Critical Nitrogen Dilution Curve for Winter Wheat. SENSORS 2020; 20:s20061577. [PMID: 32178244 PMCID: PMC7146448 DOI: 10.3390/s20061577] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/08/2020] [Accepted: 03/09/2020] [Indexed: 11/30/2022]
Abstract
Critical nitrogen (N) dilution curves (CNDCs) have been developed to describe the dilution dynamic of N and to diagnose N status in plants. In this study, to develop a convenient alternative CNDC determination method, four field experiments involving different N rates (0–360 kg N ha-1) and six wheat varieties were performed at different eco-sites from 2014 to 2019. The normalised difference red-edge (NDRE) index extracted from the RapidSCAN CS-45 (Holland Scientific Inc., Lincoln, NE, USA) sensor was used as a driving factor instead of plant dry matter (PDM) to establish a new alternative winter wheat CNDC. The newly developed CNDC was described by the equation Nc = 0.90NDRE−0.88, when NDRE values were ≤ 0.19 and constant Nc = 3.81%, which was independent of the NDRE values. Compared to PDM-derived CNDC (R2 = 0.73) developed with the same dataset, a comparable precision was obtained using NDRE-derived CNDC (R2 = 0.76) and both CNDCs could accurately discriminate wheat N status. Moreover, the NDRE could be inexpensively and rapidly measured using the active sensor. The relationship between NDRE-derived CNDC and grain yield was also analysed to facilitate in-season N management, and the R2 value reached 0.79 and 0.87 at jointing and booting stages, respectively. The NDRE-based CNDC can be used to effectively diagnose wheat N status and as an alternative approach for non-destructive determination of crop N levels.
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Affiliation(s)
| | | | | | | | | | | | | | - Xiaojun Liu
- Correspondence: ; Tel.: +86-25-8439-6804; Fax: +86-25-8439-6672
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Assessing Performance of Vegetation Indices to Estimate Nitrogen Nutrition Index in Pepper. REMOTE SENSING 2020. [DOI: 10.3390/rs12050763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Vegetation indices (VIs) can be useful tools to evaluate crop nitrogen (N) status. To be effective, VIs measurements must be related to crop N status. The nitrogen nutrition index (NNI) is a widely accepted parameter of crop N status. The present work evaluates the performance of several VIs to estimate NNI in sweet pepper (Capsicum annuum). The performance of VIs to estimate NNI was evaluated using parameters of linear regression analysis conducted for calibration and validation. Three different sweet pepper crops were grown with combined irrigation and fertigation, in Almería, Spain. In each crop, five different N concentrations in the nutrient solution were frequently applied by drip irrigation. Proximal crop reflectance was measured with Crop Circle ACS470 and GreenSeeker handheld sensors, approximately every ten days, throughout the crops. The relative performance of VIs differed between phenological stages. Relationships of VIs with NNI were strongest in the early fruit growth and flowering stages, and less strong in the vegetative and harvest stages. The green band-based VIs, GNDVI, and GVI, provided the best results for estimating crop NNI in sweet pepper, for individual phenological stages. GNDVI had the best performance in the vegetative, flowering, and harvest stages, and GVI had the best performance in the early fruit growth stage. Some of the VIs evaluated are promising tools to estimate crop N status in sweet pepper and have the potential to contribute to improving crop N management of sweet pepper crops.
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de Souza R, Grasso R, Peña-Fleitas MT, Gallardo M, Thompson RB, Padilla FM. Effect of Cultivar on Chlorophyll Meter and Canopy Reflectance Measurements in Cucumber. SENSORS 2020; 20:s20020509. [PMID: 31963226 PMCID: PMC7014412 DOI: 10.3390/s20020509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/13/2020] [Accepted: 01/14/2020] [Indexed: 11/16/2022]
Abstract
Optical sensors can be used to assess crop N status to assist with N fertilizer management. Differences between cultivars may affect optical sensor measurement. Cultivar effects on measurements made with the SPAD-502 (Soil Plant Analysis Development) meter and the MC-100 (Chlorophyll Concentration Meter), and of several vegetation indices measured with the Crop Circle ACS470 canopy reflectance sensor, were assessed. A cucumber (Cucumis sativus L.) crop was grown in a greenhouse, with three cultivars. Each cultivar received three N treatments, of increasing N concentration, being deficient (N1), sufficient (N2) and excessive (N3). There were significant differences between cultivars in the measurements made with both chlorophyll meters, particularly when N supply was sufficient and excessive (N2 and N3 treatments, respectively). There were no consistent differences between cultivars in vegetation indices. Optical sensor measurements were strongly linearly related to leaf N content in each of the three cultivars. The lack of a consistent effect of cultivar on the relationship with leaf N content suggests that a unique equation to estimate leaf N content from vegetation indices can be applied to all three cultivars. Results of chlorophyll meter measurements suggest that care should be taken when using sufficiency values, determined for a particular cultivar
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Affiliation(s)
- Romina de Souza
- Department of Agronomy, University of Almeria, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120 Almería, Spain; (M.T.P.-F.); (M.G.); (R.B.T.); (F.M.P.)
- Correspondence: ; Tel.: +34-950-014-101
| | - Rafael Grasso
- Estación Experimental INIA Salto Grande, Instituto Nacional de Investigación Agropecuaria (INIA), Camino al Terrible s/n, 50000 Salto, Uruguay;
| | - M. Teresa Peña-Fleitas
- Department of Agronomy, University of Almeria, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120 Almería, Spain; (M.T.P.-F.); (M.G.); (R.B.T.); (F.M.P.)
| | - Marisa Gallardo
- Department of Agronomy, University of Almeria, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120 Almería, Spain; (M.T.P.-F.); (M.G.); (R.B.T.); (F.M.P.)
- CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, University of Almeria, La Cañada de San Urbano, 04120 Almería, Spain
| | - Rodney B. Thompson
- Department of Agronomy, University of Almeria, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120 Almería, Spain; (M.T.P.-F.); (M.G.); (R.B.T.); (F.M.P.)
- CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, University of Almeria, La Cañada de San Urbano, 04120 Almería, Spain
| | - Francisco M. Padilla
- Department of Agronomy, University of Almeria, Carretera de Sacramento s/n, La Cañada de San Urbano, 04120 Almería, Spain; (M.T.P.-F.); (M.G.); (R.B.T.); (F.M.P.)
- CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, University of Almeria, La Cañada de San Urbano, 04120 Almería, Spain
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Improving Unmanned Aerial Vehicle Remote Sensing-Based Rice Nitrogen Nutrition Index Prediction with Machine Learning. REMOTE SENSING 2020. [DOI: 10.3390/rs12020215] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Optimizing nitrogen (N) management in rice is crucial for China’s food security and sustainable agricultural development. Nondestructive crop growth monitoring based on remote sensing technologies can accurately assess crop N status, which may be used to guide the in-season site-specific N recommendations. The fixed-wing unmanned aerial vehicle (UAV)-based remote sensing is a low-cost, easy-to-operate technology for collecting spectral reflectance imagery, an important data source for precision N management. The relationships between many vegetation indices (VIs) derived from spectral reflectance data and crop parameters are known to be nonlinear. As a result, nonlinear machine learning methods have the potential to improve the estimation accuracy. The objective of this study was to evaluate five different approaches for estimating rice (Oryza sativa L.) aboveground biomass (AGB), plant N uptake (PNU), and N nutrition index (NNI) at stem elongation (SE) and heading (HD) stages in Northeast China: (1) single VI (SVI); (2) stepwise multiple linear regression (SMLR); (3) random forest (RF); (4) support vector machine (SVM); and (5) artificial neural networks (ANN) regression. The results indicated that machine learning methods improved the NNI estimation compared to VI-SLR and SMLR methods. The RF algorithm performed the best for estimating NNI (R2 = 0.94 (SE) and 0.96 (HD) for calibration and 0.61 (SE) and 0.79 (HD) for validation). The root mean square errors (RMSEs) were 0.09, and the relative errors were <10% in all the models. It is concluded that the RF machine learning regression can significantly improve the estimation of rice N status using UAV remote sensing. The application machine learning methods offers a new opportunity to better use remote sensing data for monitoring crop growth conditions and guiding precision crop management. More studies are needed to further improve these machine learning-based models by combining both remote sensing data and other related soil, weather, and management information for applications in precision N and crop management.
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Louvieaux J, Spanoghe M, Hermans C. Root Morphological Traits of Seedlings Are Predictors of Seed Yield and Quality in Winter Oilseed Rape Hybrid Cultivars. FRONTIERS IN PLANT SCIENCE 2020; 11:568009. [PMID: 33178235 PMCID: PMC7593254 DOI: 10.3389/fpls.2020.568009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 09/22/2020] [Indexed: 05/07/2023]
Abstract
The root system is responsible for soil resources acquisition. Hence, optimizing crop root characteristics has considerable implications for agricultural production. This study evaluated a panel of twenty-eight European modern cultivars of oilseed rape (Brassica napus L.) cultivated in laboratory and field environments. Root morphology was screened using a high-throughput hydroponic growth system with two divergent nitrogen supplies. The panel showed an important diversity for biomass production and root morphological traits. Differences in root and shoot dry biomasses and lateral root length were mainly explained by the genotype, and differences in primary root length by nitrogen nutrition. The cultivars were tested in a pluriannual field trial. The field variation for yield and seed quality traits attributed to the genotype was more important than the year or the genotype × year interaction effects. The total root length measured at the seedling stage could predict the proportion of nitrogen taken up from the field and reallocated to seed organs, a component of the nitrogen use efficiency. The genetic interrelationship between cultivars, established with simple sequence repeat markers, indicated a very narrow genetic base. Positive correlations were found between the genetic distance measures, root morphological traits during nitrogen depletion and yield components. This study illustrates a root phenotyping screen in the laboratory with a proof of concept evaluation in the field. The results could assist future genetic improvements in oilseed rape for desirable root characteristics to reduce nutrient losses in the environment.
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Affiliation(s)
- Julien Louvieaux
- Crop Production and Biostimulation Laboratory, Interfacultary School of Bioengineers, Université Libre de Bruxelles, Brussels, Belgium
- Laboratory of Applied Plant Ecophysiology, Haute Ecole Provinciale de Hainaut Condorcet, Centre pour l’Agronomie et l’Agro-Industrie de la Province de Hainaut, Ath, Belgium
- *Correspondence: Julien Louvieaux,
| | - Martin Spanoghe
- Laboratory of Biotechnology and Applied Biology, Haute Ecole Provinciale de Hainaut Condorcet, Mons, Belgium
| | - Christian Hermans
- Crop Production and Biostimulation Laboratory, Interfacultary School of Bioengineers, Université Libre de Bruxelles, Brussels, Belgium
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Zhang K, Liu X, Ma Y, Zhang R, Cao Q, Zhu Y, Cao W, Tian Y. A Comparative Assessment of Measures of Leaf Nitrogen in Rice Using Two Leaf-Clip Meters. SENSORS (BASEL, SWITZERLAND) 2019; 20:E175. [PMID: 31892258 PMCID: PMC6983203 DOI: 10.3390/s20010175] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/22/2019] [Accepted: 12/24/2019] [Indexed: 11/16/2022]
Abstract
Accurate estimation and monitoring of crop nitrogen can assist in timely diagnosis and facilitate necessary technical support for fertilizer management. Four experiments, involving three cultivars and six nitrogen (N) treatments, were conducted in southeast China to compare the two leaf-clip meters (Dualex 4 Scientific+, Force-A, Orasy, France; Soil and Plant Analyzer Development (SPAD) meter, Minolta Camera Co., Osaka, Japan) for their ability to measure nitrogen nutrient-related indicators. The results indicated that Chl had a better monitoring accuracy for chlorophyll in per unit leaf area as compared to SPAD value, and there was no saturation to appear under high leaf chlorophyll concentration status. Flavonoids (Flav) presented the advantage of early diagnosis of rice N nutrition status (about one day as compared to SPAD value). As a reliable N nutrient diagnosis indicator, it also improved the estimation accuracy compared with the classical SPAD-based method. The other Dualex value also obtained good monitoring results. Flav was positively correlated with N deficiency, and with higher R2 in panicle initiation and booting stages with low RMSE, respectively; whereas SPAD value was negatively correlated with nitrogen deficiency. Therefore, the Flav-based nitrogen application model was found to provide an early rice nitrogen fertilizer application approach, especially in the panicle initiation and booting stages.
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Affiliation(s)
- Ke Zhang
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (K.Z.); (X.L.); (Y.M.); (R.Z.); (Q.C.); (Y.Z.); (W.C.)
- Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojun Liu
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (K.Z.); (X.L.); (Y.M.); (R.Z.); (Q.C.); (Y.Z.); (W.C.)
- Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Yong Ma
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (K.Z.); (X.L.); (Y.M.); (R.Z.); (Q.C.); (Y.Z.); (W.C.)
- Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Rui Zhang
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (K.Z.); (X.L.); (Y.M.); (R.Z.); (Q.C.); (Y.Z.); (W.C.)
- Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiang Cao
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (K.Z.); (X.L.); (Y.M.); (R.Z.); (Q.C.); (Y.Z.); (W.C.)
- Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Yan Zhu
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (K.Z.); (X.L.); (Y.M.); (R.Z.); (Q.C.); (Y.Z.); (W.C.)
- Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Weixing Cao
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (K.Z.); (X.L.); (Y.M.); (R.Z.); (Q.C.); (Y.Z.); (W.C.)
- Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
| | - Yongchao Tian
- National Engineering and Technology Center for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China; (K.Z.); (X.L.); (Y.M.); (R.Z.); (Q.C.); (Y.Z.); (W.C.)
- Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Key Laboratory for Information Agriculture, Nanjing Agricultural University, Nanjing 210095, China
- Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing 210095, China
- College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China
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Sun G, Ding Y, Wang X, Lu W, Sun Y, Yu H. Nondestructive Determination of Nitrogen, Phosphorus and Potassium Contents in Greenhouse Tomato Plants Based on Multispectral Three-Dimensional Imaging. SENSORS 2019; 19:s19235295. [PMID: 31805657 PMCID: PMC6928753 DOI: 10.3390/s19235295] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 11/29/2019] [Accepted: 11/29/2019] [Indexed: 11/16/2022]
Abstract
Measurement of plant nitrogen (N), phosphorus (P), and potassium (K) levels are important for determining precise fertilization management approaches for crops cultivated in greenhouses. To accurately, rapidly, stably, and nondestructively measure the NPK levels in tomato plants, a nondestructive determination method based on multispectral three-dimensional (3D) imaging was proposed. Multiview RGB-D images and multispectral images were synchronously collected, and the plant multispectral reflectance was registered to the depth coordinates according to Fourier transform principles. Based on the Kinect sensor pose estimation and self-calibration, the unified transformation of the multiview point cloud coordinate system was realized. Finally, the iterative closest point (ICP) algorithm was used for the precise registration of multiview point clouds and the reconstruction of plant multispectral 3D point cloud models. Using the normalized grayscale similarity coefficient, the degree of spectral overlap, and the Hausdorff distance set, the accuracy of the reconstructed multispectral 3D point clouds was quantitatively evaluated, the average value was 0.9116, 0.9343 and 0.41 cm, respectively. The results indicated that the multispectral reflectance could be registered to the Kinect depth coordinates accurately based on the Fourier transform principles, the reconstruction accuracy of the multispectral 3D point cloud model met the model reconstruction needs of tomato plants. Using back-propagation artificial neural network (BPANN), support vector machine regression (SVMR), and gaussian process regression (GPR) methods, determination models for the NPK contents in tomato plants based on the reflectance characteristics of plant multispectral 3D point cloud models were separately constructed. The relative error (RE) of the N content by BPANN, SVMR and GPR prediction models were 2.27%, 7.46% and 4.03%, respectively. The RE of the P content by BPANN, SVMR and GPR prediction models were 3.32%, 8.92% and 8.41%, respectively. The RE of the K content by BPANN, SVMR and GPR prediction models were 3.27%, 5.73% and 3.32%, respectively. These models provided highly efficient and accurate measurements of the NPK contents in tomato plants. The NPK contents determination performance of these models were more stable than those of single-view models.
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Affiliation(s)
- Guoxiang Sun
- College of Engineering, Nanjing Agricultural University, Nanjing 210031, China; (Y.D.); (X.W.); (W.L.); (Y.S.); (H.Y.)
- Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology & Equipment, Nanjing 210031, China
- Correspondence: ; Tel.: +86-25-5860-6585
| | - Yongqian Ding
- College of Engineering, Nanjing Agricultural University, Nanjing 210031, China; (Y.D.); (X.W.); (W.L.); (Y.S.); (H.Y.)
- Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology & Equipment, Nanjing 210031, China
| | - Xiaochan Wang
- College of Engineering, Nanjing Agricultural University, Nanjing 210031, China; (Y.D.); (X.W.); (W.L.); (Y.S.); (H.Y.)
- Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology & Equipment, Nanjing 210031, China
| | - Wei Lu
- College of Engineering, Nanjing Agricultural University, Nanjing 210031, China; (Y.D.); (X.W.); (W.L.); (Y.S.); (H.Y.)
- Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology & Equipment, Nanjing 210031, China
| | - Ye Sun
- College of Engineering, Nanjing Agricultural University, Nanjing 210031, China; (Y.D.); (X.W.); (W.L.); (Y.S.); (H.Y.)
| | - Hongfeng Yu
- College of Engineering, Nanjing Agricultural University, Nanjing 210031, China; (Y.D.); (X.W.); (W.L.); (Y.S.); (H.Y.)
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Assessment of Portable Chlorophyll Meters for Measuring Crop Leaf Chlorophyll Concentration. REMOTE SENSING 2019. [DOI: 10.3390/rs11222706] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Accurate measurement of leaf chlorophyll concentration (LChl) in the field using a portable chlorophyll meter (PCM) is crucial to support methodology development for mapping the spatiotemporal variability of crop nitrogen status using remote sensing. Several PCMs have been developed to measure LChl instantaneously and non-destructively in the field, however, their readings are relative quantities that need to be converted into actual LChl values using conversion functions. The aim of this study was to investigate the relationship between actual LChl and PCM readings obtained by three PCMs: SPAD-502, CCM-200, and Dualex-4. Field experiments were conducted in 2016 on four crops: corn (Zea mays L.), soybean (Glycine max L. Merr.), spring wheat (Triticum aestivum L.), and canola (Brassica napus L.), at the Central Experimental Farm of Agriculture and Agri-Food Canada in Ottawa, Ontario, Canada. To evaluate the impact of other factors (leaf internal structure, leaf pigments other than chlorophyll, and the heterogeneity of LChl distribution) on the conversion function, a global sensitivity analysis was conducted using the PROSPECT-D model to simulate PCM readings under different conditions. Results showed that Dualex-4 had a better performance for actual LChl measurement than SPAD-502 and CCM-200, using a general conversion function for all four crops tested. For SPAD-502 and CCM-200, the error in the readings increases with increasing LChl. The sensitivity analysis reveals that deviations from the calibration functions are more induced by non-uniform LChl distribution than leaf architectures. The readings of Dualex-4 can have a better ability to restrict these influences than those of the other two PCMs.
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Sources of Variation in Assessing Canopy Reflectance of Processing Tomato by Means of Multispectral Radiometry. SENSORS 2019; 19:s19214730. [PMID: 31683546 PMCID: PMC6864711 DOI: 10.3390/s19214730] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/22/2019] [Accepted: 10/29/2019] [Indexed: 12/05/2022]
Abstract
Canopy reflectance sensors are a viable technology to optimize the fertilization management of crops. In this research, canopy reflectance was measured through a passive sensor to evaluate the effects of either crop features (N fertilization, soil mulching, appearance of red fruits, and cultivars) or sampling methods (sampling size, sensor position, and hour of sampling) on the reliability of vegetation indices (VIs). Sixteen VIs were derived, including seven simple wavelength reflectance ratios (NIR/R460, NIR/R510, NIR/R560, NIR/R610, NIR/R660, NIR/R710, NIR/R760), seven normalized indices (NDVI, G-NDVI, MCARISAVI, OSAVI, TSAVI, TCARI), and two combined indices (TCARI/OSAVI; MCARI/OSAVI). NIR/560 and G-NDVI (Normalized Difference Vegetation Index on Greenness) were the most reliable in discriminating among fertilization rates, with results unaffected by the appearance of maturing fruits, and the most stable in response to different cultivars. Black mulching film did not affect NIR/560 and G-NDVI behavior at the beginning of the growing season, when the crop is more responsive to N management. Due to a moderate variability of NIR/560 and G-NDVI, a small sample size (5–10 observations) is sufficient to obtain reliable measurements. Performing the measurements at 11:00 and 14:00 and maintaining a greater distance (1.8 m) between plants and instrument enhanced measurement consistency. Accordingly, NIR/560 and G-NDVI resulted in the most reliable VIs.
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Predicting N Status in Maize with Clip Sensors: Choosing Sensor, Leaf Sampling Point, and Timing. SENSORS 2019; 19:s19183881. [PMID: 31505810 PMCID: PMC6766790 DOI: 10.3390/s19183881] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 11/17/2022]
Abstract
Nitrogen (N) losses from agricultural systems increase air and water pollution, and these losses are highly correlated with the excessive fertilization. An adjusted N fertilization is then a key factor in increasing the N fertilizer efficiency, and leaf clip sensors can help to improve it. This study (combining five different field experiments in Central Spain) tried to identify the ability of the clip sensors in maize N status identification and yield prediction, comparing two different devices (SPAD-502® and Dualex®) and identifying the best protocol for maize leaf sampling. As a result, the study demonstrated that different leaf clip chlorophyll sensors presented similar results, although some differences appeared at larger N concentrations. Complementary polyphenol information (as flavonol) can improve the maize N deficiency prediction. Moreover, valuable information for a proper sampling protocol was obtained with this study. It proved that the sampling position (in the leaf and in the plant) and sampling time were crucial for a better estimation of the maize N status. Proper fertilization recommendations could be achieved based on clip chlorophyll sensor measurements.
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Measurement Method Based on Multispectral Three-Dimensional Imaging for the Chlorophyll Contents of Greenhouse Tomato Plants. SENSORS 2019; 19:s19153345. [PMID: 31366151 PMCID: PMC6696012 DOI: 10.3390/s19153345] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/25/2019] [Accepted: 07/28/2019] [Indexed: 11/26/2022]
Abstract
Nondestructive plant growth measurement is essential for researching plant growth and health. A nondestructive measurement system to retrieve plant information includes the measurement of morphological and physiological information, but most systems use two independent measurement systems for the two types of characteristics. In this study, a highly integrated, multispectral, three-dimensional (3D) nondestructive measurement system for greenhouse tomato plants was designed. The system used a Kinect sensor, an SOC710 hyperspectral imager, an electric rotary table, and other components. A heterogeneous sensing image registration technique based on the Fourier transform was proposed, which was used to register the SOC710 multispectral reflectance in the Kinect depth image coordinate system. Furthermore, a 3D multiview RGB-D image-reconstruction method based on the pose estimation and self-calibration of the Kinect sensor was developed to reconstruct a multispectral 3D point cloud model of the tomato plant. An experiment was conducted to measure plant canopy chlorophyll and the relative chlorophyll content was measured by the soil and plant analyzer development (SPAD) measurement model based on a 3D multispectral point cloud model and a single-view point cloud model and its performance was compared and analyzed. The results revealed that the measurement model established by using the characteristic variables from the multiview point cloud model was superior to the one established using the variables from the single-view point cloud model. Therefore, the multispectral 3D reconstruction approach is able to reconstruct the plant multispectral 3D point cloud model, which optimizes the traditional two-dimensional image-based SPAD measurement method and can obtain a precise and efficient high-throughput measurement of plant chlorophyll.
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The Use of Chlorophyll Meters to Assess Crop N Status and Derivation of Sufficiency Values for Sweet Pepper. SENSORS 2019; 19:s19132949. [PMID: 31277420 PMCID: PMC6650809 DOI: 10.3390/s19132949] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/19/2019] [Accepted: 07/01/2019] [Indexed: 11/16/2022]
Abstract
Chlorophyll meters are promising tools for improving the nitrogen (N) management of vegetable crops. To facilitate on-farm use of these meters, sufficiency values that identify deficient and sufficient crop N status are required. This work evaluated the ability of three chlorophyll meters (SPAD-502, atLEAF+, and MC-100) to assess crop N status in sweet pepper. It also determined sufficiency values for optimal N nutrition for each meter for pepper. The experimental work was conducted in a greenhouse, in Almería, Spain, very similar to those used for commercial production, in three different crops grown with fertigation. In each crop, there were five treatments of different N concentration in the nutrient solution, applied in each irrigation, ranging from a very deficient to very excessive N supply. In general, chlorophyll meter measurements were strongly related to crop N status in all phenological stages of the three crops, indicating that these measurements are good indicators of the crop N status of pepper. Sufficiency values determined for each meter for the four major phenological stages were consistent between the three crops. This demonstrated the potential for using these meters with sufficiency values to improve the N management of commercial sweet pepper crops.
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Giraldo JP, Wu H, Newkirk GM, Kruss S. Nanobiotechnology approaches for engineering smart plant sensors. NATURE NANOTECHNOLOGY 2019; 14:541-553. [PMID: 31168083 DOI: 10.1038/s41565-019-0470-6] [Citation(s) in RCA: 178] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 05/08/2019] [Indexed: 05/18/2023]
Abstract
Nanobiotechnology has the potential to enable smart plant sensors that communicate with and actuate electronic devices for improving plant productivity, optimize and automate water and agrochemical allocation, and enable high-throughput plant chemical phenotyping. Reducing crop loss due to environmental and pathogen-related stresses, improving resource use efficiency and selecting optimal plant traits are major challenges in plant agriculture industries worldwide. New technologies are required to accurately monitor, in real time and with high spatial and temporal resolution, plant physiological and developmental responses to their microenvironment. Nanomaterials are allowing the translation of plant chemical signals into digital information that can be monitored by standoff electronic devices. Herein, we discuss the design and interfacing of smart nanobiotechnology-based sensors that report plant signalling molecules associated with health status to agricultural and phenotyping devices via optical, wireless or electrical signals. We describe how nanomaterial-mediated delivery of genetically encoded sensors can act as tools for research and development of smart plant sensors. We assess performance parameters of smart nanobiotechnology-based sensors in plants (for example, resolution, sensitivity, accuracy and durability) including in vivo optical nanosensors and wearable nanoelectronic sensors. To conclude, we present an integrated and prospective vision on how nanotechnology could enable smart plant sensors that communicate with and actuate electronic devices for monitoring and optimizing individual plant productivity and resource use.
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Affiliation(s)
- Juan Pablo Giraldo
- Department of Botany and Plant Sciences, University of California, Riverside, CA, USA.
- Center for Plant Cell Biology, University of California, Riverside, CA, USA.
- Institute of Integrative Genome Biology, University of California, Riverside, CA, USA.
| | - Honghong Wu
- Department of Botany and Plant Sciences, University of California, Riverside, CA, USA
| | | | - Sebastian Kruss
- Institute of Physical Chemistry, Georg August University Göttingen, Göttingen, Germany
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Using a Portable Active Sensor to Monitor Growth Parameters and Predict Grain Yield of Winter Wheat. SENSORS 2019; 19:s19051108. [PMID: 30841552 PMCID: PMC6427465 DOI: 10.3390/s19051108] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/27/2019] [Accepted: 03/01/2019] [Indexed: 11/17/2022]
Abstract
Rapid and effective acquisition of crop growth information is a crucial step of precision agriculture for making in-season management decisions. Active canopy sensor GreenSeeker (Trimble Navigation Limited, Sunnyvale, CA, USA) is a portable device commonly used for non-destructively obtaining crop growth information. This study intended to expand the applicability of GreenSeeker in monitoring growth status and predicting grain yield of winter wheat (Triticum aestivum L.). Four field experiments with multiple wheat cultivars and N treatments were conducted during 2013⁻2015 for obtaining canopy normalized difference vegetation index (NDVI) and ratio vegetation index (RVI) synchronized with four agronomic parameters: leaf area index (LAI), leaf dry matter (LDM), leaf nitrogen concentration (LNC), and leaf nitrogen accumulation (LNA). Duration models based on NDVI and RVI were developed to monitor these parameters, which indicated that NDVI and RVI explained 80%, 68⁻70%, 10⁻12%, and 67⁻73% of the variability in LAI, LDM, LNC and LNA, respectively. According to the validation results, the relative root mean square error (RRMSE) were all <0.24 and the relative error (RE) were all <23%. Considering the variation among different wheat cultivars, the newly normalized vegetation indices rNDVI (NDVI vs. the NDVI for the highest N rate) and rRVI (RVI vs. the RVI for the highest N rate) were calculated to predict the relative grain yield (RY, the yield vs. the yield for the highest N rate). rNDVI and rRVI explained 77⁻85% of the variability in RY, the RRMSEs were both <0.13 and the REs were both <6.3%. The result demonstrates the feasibility of monitoring growth parameters and predicting grain yield of winter wheat with portable GreenSeeker sensor.
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Itakura K, Kamakura I, Hosoi F. Three-Dimensional Monitoring of Plant Structural Parameters and Chlorophyll Distribution. SENSORS (BASEL, SWITZERLAND) 2019; 19:E413. [PMID: 30669537 PMCID: PMC6359203 DOI: 10.3390/s19020413] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/16/2019] [Accepted: 01/18/2019] [Indexed: 11/16/2022]
Abstract
Image analysis is widely used for accurate and efficient plant monitoring. Plants have complex three-dimensional (3D) structures; hence, 3D image acquisition and analysis is useful for determining the status of plants. Here, 3D images of plants were reconstructed using a photogrammetric approach, called "structure from motion". Chlorophyll content is an important parameter that determines the status of plants. Chlorophyll content was estimated from 3D images of plants with color information. To observe changes in the chlorophyll content and plant structure, a potted plant was kept for five days under a water stress condition and its 3D images were taken once a day. As a result, the normalized Red value and the chlorophyll content were correlated; a high R² value (0.81) was obtained. The absolute error of the chlorophyll content estimation in cross-validation studies was 4.0 × 10-2 μg/mm². At the same time, the structural parameters (i.e., the leaf inclination angle and the azimuthal angle) were calculated by simultaneously monitoring the changes in the plant's status in terms of its chlorophyll content and structural parameters. By combining these parameters related to plant information in plant image analysis, early detection of plant stressors, such as water stress, becomes possible.
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Affiliation(s)
- Kenta Itakura
- Graduate School, University of Tokyo, Tokyo 113-8657, Japan.
| | | | - Fumiki Hosoi
- Graduate School, University of Tokyo, Tokyo 113-8657, Japan.
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Li S, Ding X, Kuang Q, Ata-UI-Karim ST, Cheng T, Liu X, Tian Y, Zhu Y, Cao W, Cao Q. Potential of UAV-Based Active Sensing for Monitoring Rice Leaf Nitrogen Status. FRONTIERS IN PLANT SCIENCE 2018; 9:1834. [PMID: 30619407 PMCID: PMC6302087 DOI: 10.3389/fpls.2018.01834] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/27/2018] [Indexed: 05/28/2023]
Abstract
Unmanned aerial vehicle (UAV) based active canopy sensors can serve as a promising sensing solution for the estimation of crop nitrogen (N) status with great applicability and flexibility. This study was endeavored to determine the feasibility of UAV-based active sensing to monitor the leaf N status of rice (Oryza sativa L.) and to examine the transferability of handheld-based predictive models to UAV-based active sensing. In this 3-year multi-locational study, varied N-rates (0-405 kg N ha-1) field experiments were conducted using five rice varieties. Plant samples and sensing data were collected at critical growth stages for growth analysis and monitoring. The portable active canopy sensor RapidSCAN CS-45 with red, red edge, and near infrared wavebands was used in handheld mode and aerial mode on a gimbal under a multi-rotor UAV. The results showed the great potential of UAV-based active sensing for monitoring rice leaf N status. The vegetation index-based regression models were built and evaluated based on Akaike information criterion and independent validation to predict rice leaf dry matter, leaf area index, and leaf N accumulation. Vegetation indices composed of near-infrared and red edge bands (NDRE or RERVI) acquired at a 1.5 m aviation height had a good performance for the practical application. Future studies are needed on the proper operation mode and means for precision N management with this system.
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Affiliation(s)
- Songyang Li
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
| | - Xingzhong Ding
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
| | - Qianliang Kuang
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
| | - Syed Tahir Ata-UI-Karim
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Tao Cheng
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
| | - Xiaojun Liu
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
| | - Yongchao Tian
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
| | - Yan Zhu
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
| | - Weixing Cao
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
| | - Qiang Cao
- National Engineering and Technology Center for Information Agriculture (NETCIA), Key Laboratory for Crop System Analysis and Decision Making, Ministry of Agriculture, Jiangsu Key Laboratory for Information Agriculture, Jiangsu Collaborative Innovation Center for the Technology and Application of Internet of Things, Nanjing Agricultural University, Nanjing, China
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Padilla FM, de Souza R, Peña-Fleitas MT, Gallardo M, Giménez C, Thompson RB. Different Responses of Various Chlorophyll Meters to Increasing Nitrogen Supply in Sweet Pepper. FRONTIERS IN PLANT SCIENCE 2018; 9:1752. [PMID: 30542364 PMCID: PMC6277906 DOI: 10.3389/fpls.2018.01752] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 11/12/2018] [Indexed: 05/08/2023]
Abstract
Intensive vegetable production is commonly associated with excessive nitrogen (N) fertilization and associated environmental problems. Monitoring of crop N status can enhance crop N management. Chlorophyll meters (CMs) could be used to monitor crop N status because leaf chlorophyll (chl) content is strongly related to crop N status. To monitor crop N status, relationships between CM measurements and leaf chl content require evaluation, particularly when excessive N is supplied. The SPAD-502 meter, atLEAF+ sensor, MC-100 Chlorophyll Concentration Meter, and Multiplex sensor were evaluated in sweet pepper with different N supply, throughout the crop, ranging from very deficient to very excessive. CM measurements of all sensors and indices were strongly and positively related to leaf chlorophyll a + b content with curvilinear relationships over the entire range of chl measured (∼0-80 μg cm-2). Measurements with the SPAD-502, and atLEAF+, and of the Multiplex's simple fluorescence ratio index (SFR) had asymptotic responses to increasing leaf chl. In contrast, the MC-100's chlorophyll content index (CCI) had a progressively increasing response. At higher chlorophyll a + b contents (e.g., >40 μg cm-2), SPAD-502, atLEAF+ and SFR measurements tended to saturate, which did not occur with CCI. Leaf chl content was most accurately estimated by CCI (R 2 = 0.87), followed by the SPAD-502 meter (R 2 = 0.85). The atLEAF+ sensor was the least accurate (R 2 = 0.76). For leaf chl estimation, CCI measured with the MC-100 meter was the most effective of the four sensors examined because it: (1) most accurately estimated leaf chl content, and (2) had no saturation response at higher leaf chl content. For non-saturating leaf chl content (∼0-40 μg cm-2), all indices were sensitive indicators. As excessive applications of N are frequent in intensive vegetable crop production, the capacity of measuring high leaf chl contents without a saturation response is an important consideration for the practical use of chlorophyll meters.
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Affiliation(s)
- Francisco M. Padilla
- CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, Department of Agronomy, University of Almería, Almeria, Spain
- *Correspondence: Francisco M. Padilla,
| | - Romina de Souza
- CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, Department of Agronomy, University of Almería, Almeria, Spain
| | - M. Teresa Peña-Fleitas
- CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, Department of Agronomy, University of Almería, Almeria, Spain
| | - Marisa Gallardo
- CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, Department of Agronomy, University of Almería, Almeria, Spain
| | - Carmen Giménez
- Department of Agronomy, University of Córdoba, Córdoba, Spain
| | - Rodney B. Thompson
- CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, Department of Agronomy, University of Almería, Almeria, Spain
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