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Chan CS, Dykes GE, Hoover RL, Limmer MA, Seyfferth AL. Gallionellaceae in rice root plaque: metabolic roles in iron oxidation, nutrient cycling, and plant interactions. Appl Environ Microbiol 2023; 89:e0057023. [PMID: 38009924 PMCID: PMC10734482 DOI: 10.1128/aem.00570-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 09/18/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE In waterlogged soils, iron plaque forms a reactive barrier between the root and soil, collecting phosphate and metals such as arsenic and cadmium. It is well established that iron-reducing bacteria solubilize iron, releasing these associated elements. In contrast, microbial roles in plaque formation have not been clear. Here, we show that there is a substantial population of iron oxidizers in plaque, and furthermore, that these organisms (Sideroxydans and Gallionella) are distinguished by genes for plant colonization and nutrient fixation. Our results suggest that iron-oxidizing and iron-reducing bacteria form and remodel iron plaque, making it a dynamic system that represents both a temporary sink for elements (P, As, Cd, C, etc.) as well as a source. In contrast to abiotic iron oxidation, microbial iron oxidation results in coupled Fe-C-N cycling, as well as microbe-microbe and microbe-plant ecological interactions that need to be considered in soil biogeochemistry, ecosystem dynamics, and crop management.
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Affiliation(s)
- Clara S. Chan
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- School of Marine Science and Policy, University of Delaware, Newark, Delaware, USA
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
| | - Gretchen E. Dykes
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
| | - Rene L. Hoover
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
| | - Matt A. Limmer
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
| | - Angelia L. Seyfferth
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
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Ning L, Xu X, Zhang Y, Zhao S, Qiu S, Ding W, Zou G, He P. Effects of chicken manure substitution for mineral nitrogen fertilizer on crop yield and soil fertility in a reduced nitrogen input regime of North-Central China. FRONTIERS IN PLANT SCIENCE 2022; 13:1050179. [PMID: 36589091 PMCID: PMC9798097 DOI: 10.3389/fpls.2022.1050179] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Organic manure has been proposed to substitute part of the chemical fertilizers. However, past research was usually conducted in regimes with excessive nitrogen (N) fertilization, which was not conducive to the current national goal of green and sustainable development. Therefore, exploring the potential of organic fertilizer substitution for mineral N fertilizer under regimes with reduced N inputs is important to further utilize organic fertilizer resources and establish sustainable nutrient management recommendations in the winter wheat (Triticum aestivum L.) - summer maize (Zea mays L.) rotation system in North-central China. In this study, a 4-year field experiment was conducted to investigate the effects of different chicken manure substitution ratios on crop yield, N recovery efficiency (REN), soil N and soil organic matter contents, to clarify the optimal organic substitution ratio of N fertilizer under reduced N application (from 540 kg N ha-1 year-1 to 400 kg N ha-1 year-1). Six substitution ratios were assessed: 0%, 20%, 40%, 60%, 80% and 100% under 200 kg N ha-1 per crop season, respectively, plus a control with no N application from chemical fertilizer or chicken manure. Results showed that the highest yield was achieved under the 20% substitution ratio treatment, with 1.1% and 2.3% higher yield than chemical N alone in wheat season and maize seasons, respectively. At the chicken manure substitution ratios of 20% in wheat season and 20%-40% in maize season, the highest REN reached to 31.2% and 26.1%, respectively. Chicken manure application reduced soil residual inorganic N with increasing substitution ratio. All organic substitution treatments increased soil organic matter and total N content. Implementing 20% organic substitution in wheat season and 20%-40% in maize season under the reduced N application regime in the North-central China is therefore recommended in order to achieve high crop yields and REN, improve soil fertility and enhance livestock manure resource utilization.
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Affiliation(s)
- Linyirui Ning
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xinpeng Xu
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yitao Zhang
- Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
| | - Shicheng Zhao
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shaojun Qiu
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wencheng Ding
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Guoyuan Zou
- Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Ping He
- Key Laboratory of Plant Nutrition and Fertilizer, Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China
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Kurniawan AH, Sato S, Cheng W, Dewi PK, Kobayashi K. Animal abundance and soil properties affected by long-term organic farming in rice paddies in a typical Japanese yatsuda landscape. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:273. [PMID: 33988816 DOI: 10.1007/s10661-020-08813-1] [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: 01/31/2019] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
Organic farming was developed to reduce agriculture's negative impacts on the environment and enhance biodiversity for sustainable productivity in agricultural ecosystems, but the long-term effectiveness of its application in Japanese rice paddies is unclear. We sought to understand how long-term organic farming affects the abundance of animals in both the rice growth and fallow seasons, and how soil properties change. We investigated the abundance of fishes, frogs, beetles, and shellfish in the floodwater in summer, and the abundance of earthworms (mainly Enchytraeidae), arthropods (spiders and springtails), and soil properties in aerobic soils in autumn. We examined fields which had been farmed organically for 10 and 18 years in Tochigi, Japan. Fields farmed with conventional management, located close to the selected organic fields, were used as a control. All selected fields were located in a valley, which is the typical landscape of a traditional Japanese farming village, called a yatsuda in Japanese. The results showed an increase in soil organic carbon, total nitrogen, and available phosphorus in plowed soils that had been converted from conventional to organic farming both 10 and 18 years earlier. However, the abundance of various animals were not affected significantly by long-term organic rice farming, other than arthropods in the aerobic soils that had been farmed organically for 18 years. The quantity of most animals in floodwater and fallow season soil was unaffected by long-term organic rice farming in the yatsuda paddy fields, probably due to the circumstances and similar irrigation systems for both conventional and organic rice farming, as well as lighter doses of agrochemical application for conventional rice cultivation.
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Affiliation(s)
- Andreas Hendracipta Kurniawan
- The United Graduate School of Agricultural Sciences, Iwate University, Morioka, 020-8550, Japan
- Charles River Laboratories Japan, Inc., Ishioka, 315-0138, Japan
| | - Satoru Sato
- Faculty of Agriculture, Yamagata University, Tsuruoka, 997-8555, Japan.
| | - Weiguo Cheng
- The United Graduate School of Agricultural Sciences, Iwate University, Morioka, 020-8550, Japan.
- Faculty of Agriculture, Yamagata University, Tsuruoka, 997-8555, Japan.
| | - Putri Kusuma Dewi
- Faculty of Agriculture, Yamagata University, Tsuruoka, 997-8555, Japan
| | - Kazuhiko Kobayashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
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Gao H, Sha Z, Wang F, Fang K, Dai W, Yi X, Cao L. Nitrogen leakage in a rice-duck co-culture system with different fertilizer treatments in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 686:555-567. [PMID: 31185403 DOI: 10.1016/j.scitotenv.2019.05.460] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/28/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
Nitrogen (N) leakage in paddy fields can cause groundwater pollution. In this study, we conducted a split-plot field experiment over 2 years to compare N leakage in a rice-duck co-culture system and a rice monoculture system with different fertilizer treatments. Four treatments were applied to each field, with consistent N inputs in each fertilizer treatment: no fertilizer (RD and RM, respectively), chemical fertilizer (RDF and RMF, respectively), organic fertilizer (RDO and RMO, respectively), and a mixture of 70% chemical and 30% organic fertilizers (RDFO and RMFO, respectively). In both years, rice-duck co-culture system had lower N leakage than the rice monoculture for the same fertilizer treatment, with average reductions of 14.3 ± 0.1%, 13.5 ± 4.5% and 10.5 ± 3.3% for RDFO, RDF and RDO, respectively. Within the rice-duck co-culture system, the average N leakage across both years was 36.3 ± 6.3% lower in RDO and 16.9 ± 11.5% lower in RDFO than in RMF. RDFO gave the highest grain yield compared with RDF and RDO, average reached 10.35 t ha-1 across both years. In conclusion, our results suggested that rice-duck co-culture reduces environmental risks by controlling N leakage and increasing agricultural productivity. Compared with other treatments in this research, RDFO was the most recommended agricultural production mode in this region because it can reduce the inputs of chemical fertilizer, control nitrogen leakage and increase rice yield.
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Affiliation(s)
- Hui Gao
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Zhimin Sha
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
| | - Feng Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Kaikai Fang
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Wei Dai
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiaomei Yi
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Linkui Cao
- School of Agriculture and Biology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
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Sun H, Min J, Zhang H, Feng Y, Lu K, Shi W, Yu M, Li X. Biochar application mode influences nitrogen leaching and NH 3 volatilization losses in a rice paddy soil irrigated with N-rich wastewater. ENVIRONMENTAL TECHNOLOGY 2018; 39:2090-2096. [PMID: 28662597 DOI: 10.1080/09593330.2017.1349839] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Impacts of biochar application mode on nitrogen (N) leaching, ammonia (NH3) volatilization, rice grain yield and N use efficiency (NUE) are not well understood. Therefore, a field experiment was conducted to evaluate those impacts in a rice paddy soil received 225 kg N ha-1 from either urea or N-rich wastewater. One treatment received 10 t ha-1 biochar with the basal fertilization, and the other received same total amount of biochar but split applied with the three split N applications with same ratio as N fertilizer split ratio (40%, 30% and 30%). Results showed that N leaching loads were 4.20-6.22 kg ha-1. Biochar one-time application reduced N leaching by 23.1%, and biochar split application further reduced N leaching by 32.4%. Total NH3 volatilization loss was 15.5-24.5 kg ha-1. Biochar one-time application did not influence the NH3 volatilization, but biochar split application stimulated the cumulative NH3 volatilization by 57.7%. Both biochar treatments had no influence on NUE and rice grain yield. In conclusion, biochar application mode indeed influences the N leaching and NH3 volatilization in rice paddy soils, and biochar one-time application should be recommended for reducing N leaching without increasing NH3 volatilization.
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Affiliation(s)
- Haijun Sun
- a Department of Horticulture , Foshan University , Foshan , People's Republic of China
- b State Key Laboratory of Soil and Sustainable Agriculture , Institute of Soil Science, Chinese Academy of Sciences , Nanjing , People's Republic of China
| | - Ju Min
- b State Key Laboratory of Soil and Sustainable Agriculture , Institute of Soil Science, Chinese Academy of Sciences , Nanjing , People's Republic of China
| | - Hailin Zhang
- c Department of Plant and Soil Sciences , Oklahoma State University , Stillwater , OK , USA
| | - Yanfang Feng
- d Institute of Agricultural Resources and Environment , Jiangsu Academy of Agriculture Sciences , Nanjing , People's Republic of China
| | - Kouping Lu
- e Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, School of Environmental and Resource Sciences , Zhejiang A&F University , Lin'an , People's Republic of China
| | - Weiming Shi
- b State Key Laboratory of Soil and Sustainable Agriculture , Institute of Soil Science, Chinese Academy of Sciences , Nanjing , People's Republic of China
| | - Min Yu
- a Department of Horticulture , Foshan University , Foshan , People's Republic of China
| | - Xuewen Li
- a Department of Horticulture , Foshan University , Foshan , People's Republic of China
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Zhao Z, Sha Z, Liu Y, Wu S, Zhang H, Li C, Zhao Q, Cao L. Modeling the impacts of alternative fertilization methods on nitrogen loading in rice production in Shanghai. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 566-567:1595-1603. [PMID: 27317135 DOI: 10.1016/j.scitotenv.2016.06.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/09/2016] [Accepted: 06/09/2016] [Indexed: 06/06/2023]
Abstract
Nitrogen (N) loss from paddy fields is an important source of agricultural non-point source pollution that leads to eutrophication of water bodies and degradation of water quality. The impacts of alternative N fertilizer management practices on N loading (N loss through runoff and leaching) from paddy fields in Shanghai were assessed using a process-based biogeochemical model, DNDC. The results indicated that the current fertilization rate in paddy fields of Shanghai (300kgN/ha) exceeds the actual rice demand and has led to substantial N loading of 1142±276kg. The combined application of urea at 150kgN/ha and organic manure at 100kgN/ha was identified as the best fertilization method for rice cultivation in Shanghai; this application maintained optimal rice yields and significantly reduced N loading to 714±151kg in comparison with the current fertilization rate. A sensitivity test was conducted with various input parameters, and the results indicated that fertilization, precipitation and soil properties were the most sensitive factors that regulate N loss from paddy fields. The variability of soil properties, especially SOC led to high uncertainties in the simulated results. Therefore, the local climate conditions and soil properties should be taken into account in the identification of the best management practice (BMP) for rice cultivation, given the high spatially heterogeneous N loading values across all towns used in the simulation. The DNDC model is an effective approach for simulating and predicting N loading in paddy fields under alternative agricultural management practices.
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Affiliation(s)
- Zheng Zhao
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; Eco-environmental Protection Institute of Shanghai Academy of Agricultural Science, Shanghai 201403, China
| | - Zhimin Sha
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yibo Liu
- Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China; Institute for the Study of Earth, Ocean and Space, University of New Hampshire, Durham, NH 03824, USA
| | - Shuhang Wu
- Eco-environmental Protection Institute of Shanghai Academy of Agricultural Science, Shanghai 201403, China
| | - Hanlin Zhang
- Eco-environmental Protection Institute of Shanghai Academy of Agricultural Science, Shanghai 201403, China
| | - Changsheng Li
- Institute for the Study of Earth, Ocean and Space, University of New Hampshire, Durham, NH 03824, USA
| | - Qi Zhao
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Linkui Cao
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
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Yang H, Xu M, Koide RT, Liu Q, Dai Y, Liu L, Bian X. Effects of ditch-buried straw return on water percolation, nitrogen leaching and crop yields in a rice-wheat rotation system. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2016; 96:1141-9. [PMID: 25847361 DOI: 10.1002/jsfa.7196] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 03/25/2015] [Accepted: 03/30/2015] [Indexed: 05/28/2023]
Abstract
BACKGROUND Crop residue management and nitrogen loss are two important environmental problems in the rice-wheat rotation system in China. This study investigated the effects of burial of straw on water percolation, nitrogen loss by leaching, crop growth and yield. Greenhouse mesocosm experiments were conducted over the course of three simulated cropping seasons in a rice1-wheat-rice2 rotation. RESULTS Greater amounts of straw resulted in more water percolation, irrespective of crop season. Burial at 20 and 35 cm significantly reduced, but burial at 50 cm increased nitrogen leaching. Straw at 500 kg ha(-1) reduced, but at 1000 kg ha(-1) and at 1500 kg ha(-1) straw increased nitrogen leaching in three consecutive crop rotations. In addition, straw at 500 kg ha(-1) buried at 35 cm significantly increased yield and its components for both crops. CONCLUSIONS This study suggests that N losses via leaching from the rice-wheat rotation may be reduced by the burial of the appropriate amount of straw at the appropriate depth. Greater amounts of buried straw, however, may promote nitrogen leaching and negatively affect crop growth and yields. Complementary field experiments must be performed to make specific agronomic recommendations.
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Affiliation(s)
- Haishui Yang
- Key Laboratory of Crop Physiology, Ecology and Production Management, Nanjing Agricultural University, Nanjing, 210095, China
| | - Mingmin Xu
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Roger T Koide
- Department of Biology, Brigham Young University, Provo, UT, 84602, USA
| | - Qian Liu
- Key Laboratory of Crop Physiology, Ecology and Production Management, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yajun Dai
- Key Laboratory of Crop Physiology, Ecology and Production Management, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ling Liu
- College of Agriculture, Henan University of Science and Technology, Luoyang, 471003, China
| | - Xinmin Bian
- Key Laboratory of Crop Physiology, Ecology and Production Management, Nanjing Agricultural University, Nanjing, 210095, China
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Qin L, Wang Y, Wu Y, Wang Q, Luo L. Assessment of nitrate leakage and N2O emission from five environmental-friendly agricultural practices using fuzzy logic method and empirical formula. ENVIRONMENTAL MONITORING AND ASSESSMENT 2015; 187:371. [PMID: 26003184 DOI: 10.1007/s10661-015-4569-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 04/26/2015] [Indexed: 06/04/2023]
Abstract
Agricultural nonpoint source pollution in China has been the major environmental problem, so environmental-friendly agricultural practices (EAPs) must be promoted to improve environmental quality. However, the most suitable practices for each agricultural region must first be identified. Thus, in the presented study a fuzzy-logic method and a revised empirical formula were used to assess nitrate leakage and N2O emissions, respectively, and to compare five EAPs in Xinxiang, a major grain-producing county in Henan Province, China. The required information was collected in face-to-face interviews with 10 extension service experts from the county, using a questionnaire to explore their opinions of the EAPs currently adopted by smallholder farmers, as well as the amounts, frequencies, varieties and proportions of nitrogen fertilizers applied annually. The results indicate that reduced tillage, soil testing and fertilizer recommendations would be the most appropriate practices to initially promote on a large scale in Xinxiang.
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Affiliation(s)
- Lihuan Qin
- Agricultural Clean Watershed Group, Institute of Environment and Sustainable Development in Agriculture, CAAS, Key Laboratory for Agricultural Environment MOA, Beijing, 100081, China
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Meng F, Olesen JE, Sun X, Wu W. Inorganic nitrogen leaching from organic and conventional rice production on a newly claimed calciustoll in Central Asia. PLoS One 2014; 9:e98138. [PMID: 24858826 PMCID: PMC4032263 DOI: 10.1371/journal.pone.0098138] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 04/29/2014] [Indexed: 11/24/2022] Open
Abstract
Characterizing the dynamics of nitrogen (N) leaching from organic and conventional paddy fields is necessary to optimize fertilization and to evaluate the impact of these contrasting farming systems on water bodies. We assessed N leaching in organic versus conventional rice production systems of the Ili River Valley, a representative aquatic ecosystem of Central Asia. The N leaching and overall performance of these systems were measured during 2009, using a randomized block experiment with five treatments. PVC pipes were installed at soil depths of 50 and 180 cm to collect percolation water from flooded organic and conventional paddies, and inorganic N (NH4-N+NO3-N) was analyzed. Two high-concentration peaks of NH4-N were observed in all treatments: one during early tillering and a second during flowering. A third peak at the mid-tillering stage was observed only under conventional fertilization. NO3-N concentrations were highest at transplant and then declined until harvest. At the 50 cm soil depth, NO3-N concentration was 21–42% higher than NH4-N in percolation water from organic paddies, while NH4-N and NO3-N concentrations were similar for the conventional and control treatments. At the depth of 180 cm, NH4-N and NO3-N were the predominant inorganic N for organic and conventional paddies, respectively. Inorganic N concentrations decreased with soil depth, but this attenuation was more marked in organic than in conventional paddies. Conventional paddies leached a higher percentage of applied N (0.78%) than did organic treatments (0.32–0.60%), but the two farming systems leached a similar amount of inorganic N per unit yield (0.21–0.34 kg N Mg−1 rice grains). Conventional production showed higher N utilization efficiency compared to fertilized organic treatments. These results suggest that organic rice production in the Ili River Valley is unlikely to reduce inorganic N leaching, if high crop yields similar to conventional rice production are to be maintained.
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Affiliation(s)
- Fanqiao Meng
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
- * E-mail:
| | - Jørgen E. Olesen
- Department of Agroecology and Environment, Faculty of Agricultural Sciences, Aarhus University, Tjele, Denmark
| | - Xiangping Sun
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
| | - Wenliang Wu
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
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Liang XQ, Harter T, Porta L, van Kessel C, Linquist BA. Nitrate leaching in californian rice fields: a field- and regional-scale assessment. JOURNAL OF ENVIRONMENTAL QUALITY 2014; 43:881-894. [PMID: 25602817 DOI: 10.2134/jeq2013.10.0402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Irrigated croplands can be a major source of nitrate-N (NO-N) in groundwater due to leaching. In California, where high NO-N levels have been found in some areas of the Central Valley aquifer, the contribution from rice systems has not been determined. Nitrate leaching from rice systems was evaluated from soil cores (0-2 m), from the fate of N fertilizer in replicated microplots, and from about 145 regional groundwater wells. Soil NO-N concentrations were ≤3.3 mg kg (usually <1 mg kg) below the root zone (below 33 cm depth). In pore-water samples, NO-N was observed only below the root zone during the first 2 wk after the onset of flooding in either the growing season or the winter fallow period and was always ≤8.4 mg L. Fertilizer N accounted for 0 to 11.8% of NO-N in pore-water samples below the root zone. One year after application, based on an analysis of soil core samples, on average 2.5% of fertilizer N was recovered as N below the root zone (33-100 cm), possibly due to leaching in permeable soils or via preferential flow through cracks in heavy clay soils. Based on a regional assessment, groundwater samples from wells that are located in proximity to rice fields all had measured median NO-N and NO-N levels below 1 mg L. These results indicate that NO-N leaching from the majority of California rice systems poses little risk to groundwater under current crop management practices.
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