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Lucas M, Rohe L, Apelt B, Stange CF, Vogel HJ, Well R, Schlüter S. The distribution of particulate organic matter in the heterogeneous soil matrix - Balancing between aerobic respiration and denitrification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175383. [PMID: 39147062 DOI: 10.1016/j.scitotenv.2024.175383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 07/25/2024] [Accepted: 08/06/2024] [Indexed: 08/17/2024]
Abstract
Denitrification, a key process in soil nitrogen cycling, occurs predominantly within microbial hotspots, such as those around particulate organic matter (POM), where denitrifiers use nitrate as an alternative electron acceptor. For accurate prediction of dinitrogen (N2) and nitrous oxide (N2O) emissions from denitrification, a precise quantification of these microscale hotspots is required. The distribution of POM is of crucial importance in this context, as the local oxygen (O2) balance is governed not only by its high O2 demand but also by the local O2 availability. Employing a unique combination of X-ray CT imaging, microscale O2 measurements, and 15N labeling, we were able to quantify hotspots of aerobic respiration and denitrification. We analyzed greenhouse gas (GHG) fluxes, soil oxygen supply, and the distribution of POM in intact soil samples from grassland and cropland under different moisture conditions. Our findings reveal that both proximal and distal POM, identified through X-ray CT imaging, contribute to GHG emissions. The distal POM, i.e. POM at distant locations to air-filled pores, emerged as a primary driver of denitrification within structured soils of both land uses. Thus, the higher denitrification rates in the grassland could be attributed to the higher content of distal POM. Conversely, despite possessing compacted areas that could favor denitrification, the cropland had only small amounts of distal POM to stimulate denitrification in it. This underlines the complex interaction between soil structural heterogeneity, organic carbon supply, and microbial hotspot formation and thus contributes to a better understanding of soil-related GHG emissions. In summary, our study provides a holistic understanding of soil-borne greenhouse gas emissions and emphasizes the need to refine predictive models for soil denitrification and N2O emissions by incorporating the microscale distribution of POM.
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Affiliation(s)
- Maik Lucas
- Helmholtz Centre for Environmental Research - UFZ, Department Soil System Sciences, Halle (Saale), Germany; Institute of Ecology, Chair of Soil Science, Technical University Berlin, 10587 Berlin, Germany.
| | - Lena Rohe
- Thünen Institute of Climate-Smart Agriculture, Bundesallee 65, 38116 Braunschweig, Germany
| | - Bernd Apelt
- Helmholtz Centre for Environmental Research - UFZ, Department Soil System Sciences, Halle (Saale), Germany
| | - Claus Florian Stange
- Federal Institute for Geoscience and Natural Resources-BGR, Department Soil as Resource - Properties and Dynamics, Stilleweg 2, 30655 Hannover, Germany
| | - Hans-Jörg Vogel
- Helmholtz Centre for Environmental Research - UFZ, Department Soil System Sciences, Halle (Saale), Germany
| | - Reinhard Well
- Thünen Institute of Climate-Smart Agriculture, Bundesallee 65, 38116 Braunschweig, Germany
| | - Steffen Schlüter
- Helmholtz Centre for Environmental Research - UFZ, Department Soil System Sciences, Halle (Saale), Germany
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Colombi T, Pandey BK, Chawade A, Bennett MJ, Mooney SJ, Keller T. Root plasticity versus elasticity - when are responses acclimative? TRENDS IN PLANT SCIENCE 2024; 29:856-864. [PMID: 38355326 DOI: 10.1016/j.tplants.2024.01.003] [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: 08/29/2023] [Revised: 12/27/2023] [Accepted: 01/23/2024] [Indexed: 02/16/2024]
Abstract
Spatiotemporal soil heterogeneity and the resulting edaphic stress cycles can be decisive for crop growth. However, our understanding of the acclimative value of root responses to heterogeneous soil conditions remains limited. We outline a framework to evaluate the acclimative value of root responses that distinguishes between stress responses that are persistent and reversible upon stress release, termed 'plasticity' and 'elasticity', respectively. Using energy balances, we provide theoretical evidence that the advantage of plasticity over elasticity increases with the number of edaphic stress cycles and if responses lead to comparatively high energy gains. Our framework provides a conceptual basis for assessing the acclimative value of root responses to soil heterogeneity and can catalyse research on crop adaptations to heterogeneous belowground environments.
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Affiliation(s)
- Tino Colombi
- Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 75007, Uppsala, Sweden.
| | - Bipin K Pandey
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Aakash Chawade
- Department of Plant Breeding, Swedish University of Agricultural Sciences, Sundsvägen 10, 23456 Alnarp, Sweden
| | - Malcolm J Bennett
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Sacha J Mooney
- School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Thomas Keller
- Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 75007, Uppsala, Sweden; Department of Agroecology and Environment, Agroscope, Reckenholzstrasse 191, CH-8046, Zürich, Switzerland
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3
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Li Z, Kravchenko AN, Cupples A, Guber AK, Kuzyakov Y, Philip Robertson G, Blagodatskaya E. Composition and metabolism of microbial communities in soil pores. Nat Commun 2024; 15:3578. [PMID: 38678028 PMCID: PMC11055953 DOI: 10.1038/s41467-024-47755-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 04/11/2024] [Indexed: 04/29/2024] Open
Abstract
Delineation of microbial habitats within the soil matrix and characterization of their environments and metabolic processes are crucial to understand soil functioning, yet their experimental identification remains persistently limited. We combined single- and triple-energy X-ray computed microtomography with pore specific allocation of 13C labeled glucose and subsequent stable isotope probing to demonstrate how long-term disparities in vegetation history modify spatial distribution patterns of soil pore and particulate organic matter drivers of microbial habitats, and to probe bacterial communities populating such habitats. Here we show striking differences between large (30-150 µm Ø) and small (4-10 µm Ø) soil pores in (i) microbial diversity, composition, and life-strategies, (ii) responses to added substrate, (iii) metabolic pathways, and (iv) the processing and fate of labile C. We propose a microbial habitat classification concept based on biogeochemical mechanisms and localization of soil processes and also suggests interventions to mitigate the environmental consequences of agricultural management.
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Affiliation(s)
- Zheng Li
- Department to Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA
| | - Alexandra N Kravchenko
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA.
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, USA.
| | - Alison Cupples
- Department to Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA
| | - Andrey K Guber
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, USA
| | - Yakov Kuzyakov
- Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil Science, University of Göttingen, Göttingen, Germany
| | - G Philip Robertson
- DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, USA
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
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Xiao T, Li P, Fei W, Wang J. Effects of vegetation roots on the structure and hydraulic properties of soils: A perspective review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167524. [PMID: 37793452 DOI: 10.1016/j.scitotenv.2023.167524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/22/2023] [Accepted: 09/29/2023] [Indexed: 10/06/2023]
Abstract
This paper aims to provide a state-of-the-art review on the effects of vegetation roots on the soil structure and soil hydraulic properties. After a thorough review of current studies, the effects of vegetation roots are summarized into four: root exudation, root penetration, root water uptake and root decay. Root exudates alter the size and stability of aggregates, the contact angle of soil, and the viscosity and surface tension of pore fluid; root exudates of crops always increase the soil water retention capacity and decrease the soil saturated hydraulic conductivity. Root penetration creates new pores or clogs existing pores during root growth, and root parameters (e.g., root biomass density, root diameter and root length density) are well correlated to soil hydraulic properties. Root water uptake can apparently increase the soil water retention capacity by providing an additional negative pressure and induce micro-fissures and macropores in the rhizosphere soil. Root decay modifies the pore structure and water repellency of soil, resulting in the increase of soil macro-porosity, soil water retention, and the saturated hydraulic conductivity or steady infiltration rate. Some of the above four effects may be difficult to be distinguished, and most importantly each is highly time-dependent and influenced by a multitude of plant-related and soil-related factors. Therefore, it remains a significant challenge to comprehend and quantify the effects of vegetation roots on the soil structure and soil hydraulic properties. Unsolved questions and disputes that require further investigations in the future are summarized in this review.
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Affiliation(s)
- Tao Xiao
- State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China.
| | - Ping Li
- State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China; Water Cycle and Geological Environment Observation and Research Station for the Chinese Loess Plateau, Ministry of Education, Zhengning 745339, China.
| | - Wenbin Fei
- Department of Infrastructure Engineering, The University of Melbourne, Parkville, Australia.
| | - Jiading Wang
- State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, China.
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Duddek P, Ahmed MA, Javaux M, Vanderborght J, Lovric G, King A, Carminati A. The effect of root hairs on root water uptake is determined by root-soil contact and root hair shrinkage. THE NEW PHYTOLOGIST 2023; 240:2484-2497. [PMID: 37525254 DOI: 10.1111/nph.19144] [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: 05/24/2023] [Accepted: 06/29/2023] [Indexed: 08/02/2023]
Abstract
The effect of root hairs on water uptake remains controversial. In particular, the key root hair and soil parameters that determine their importance have been elusive. We grew maize plants (Zea mays) in microcosms and scanned them using synchrotron-based X-ray computed microtomography. By means of image-based modelling, we investigated the parameters determining the effectiveness of root hairs in root water uptake. We explicitly accounted for rhizosphere features (e.g. root-soil contact and pore structure) and took root hair shrinkage of dehydrated root hairs into consideration. Our model suggests that > 85% of the variance in root water uptake is explained by the hair-induced increase in root-soil contact. In dry soil conditions, root hair shrinkage reduces the impact of hairs substantially. We conclude that the effectiveness of root hairs on root water uptake is determined by the hair-induced increase in root-soil contact and root hair shrinkage. Although the latter clearly reduces the effect of hairs on water uptake, our model still indicated facilitation of water uptake by root hairs at soil matric potentials from -1 to -0.1 MPa. Our findings provide new avenues towards a mechanistic understanding of the role of root hairs on water uptake.
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Affiliation(s)
- Patrick Duddek
- Department of Environmental Systems Science, Physics of Soils and Terrestrial Ecosystems, Institute of Terrestrial Ecosystems, ETH Zürich, Universitätsstrasse 16, 8092, Zurich, Switzerland
| | - Mutez Ali Ahmed
- Root-Soil Interactions, School of Life Sciences, Technical University of Munich, D-85354, Freising, Germany
| | - Mathieu Javaux
- Agrosphere Institute, IBG-3, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Jan Vanderborght
- Agrosphere Institute, IBG-3, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Goran Lovric
- Swiss Light Source, Paul Scherrer Institute, Forschungsstrasse 111, 5232, Villigen, Switzerland
| | - Andrew King
- Synchrotron SOLEIL, L'Orme des Merisiers, 91192, Gif-sur-Yvette Cedex, France
| | - Andrea Carminati
- Department of Environmental Systems Science, Physics of Soils and Terrestrial Ecosystems, Institute of Terrestrial Ecosystems, ETH Zürich, Universitätsstrasse 16, 8092, Zurich, Switzerland
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Lucas M, Santiago JP, Chen J, Guber A, Kravchenko A. The soil pore structure encountered by roots affects plant-derived carbon inputs and fate. THE NEW PHYTOLOGIST 2023; 240:515-528. [PMID: 37532958 DOI: 10.1111/nph.19159] [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: 05/12/2023] [Accepted: 07/05/2023] [Indexed: 08/04/2023]
Abstract
Plant roots are the main supplier of carbon (C) to the soil, the largest terrestrial C reservoir. Soil pore structure drives root growth, yet how it affects belowground C inputs remains a critical knowledge gap. By combining X-ray computed tomography with 14 C plant labelling, we identified root-soil contact as a previously unrecognised influence on belowground plant C allocations and on the fate of plant-derived C in the soil. Greater contact with the surrounding soil, when the growing root encounters a pore structure dominated by small (< 40 μm Ø) pores, results in strong rhizodeposition but in areas of high microbial activity. The root system of Rudbeckia hirta revealed high plasticity and thus maintained high root-soil contact. This led to greater C inputs across a wide range of soil pore structures. The root-soil contact Panicum virgatum, a promising bioenergy feedstock crop, was sensitive to the encountered structure. Pore structure built by a polyculture, for example, restored prairie, can be particularly effective in promoting lateral root growth and thus root-soil contact and associated C benefits. The findings suggest that the interaction of pore structure with roots is an important, previously unrecognised, stimulus of soil C gains.
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Affiliation(s)
- Maik Lucas
- Department of Plant, Soil and Microbial Sciences, DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA
- Department of Soil System Sciences, Helmholtz Centre for Environmental Research - UFZ, Halle (Saale), 06110, Germany
| | - James P Santiago
- Plant Resilience Institute and MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Jinyi Chen
- Department of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Andrey Guber
- Department of Plant, Soil and Microbial Sciences, DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA
| | - Alexandra Kravchenko
- Department of Plant, Soil and Microbial Sciences, DOE Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI, 48824, USA
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Skilleter P, Nelson D, Dodd IC. Cultivar-dependent differences in tuber growth cause increased soil resistance in potato fields. FRONTIERS IN PLANT SCIENCE 2023; 14:1095790. [PMID: 37342146 PMCID: PMC10278232 DOI: 10.3389/fpls.2023.1095790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 05/18/2023] [Indexed: 06/22/2023]
Abstract
Since soil compaction of potato fields delays shoot emergence and decreases total yield, the causes and effects of this compaction need to be better understood. In a controlled environment trial with young (before tuber initiation) plants, roots of cv. Inca Bella (a phureja group cultivar) were more sensitive to increased soil resistance (3.0 MPa) than cv. Maris Piper (a tuberosum group cultivar). Such variation was hypothesized to cause yield differences in two field trials, in which compaction treatments were applied after tuber planting. Trial 1 increased initial soil resistance from 0.15 MPa to 0.3 MPa. By the end of the growing season, soil resistance increased three-fold in the upper 20 cm of the soil, but resistance in Maris Piper plots was up to twice that of Inca Bella plots. Maris Piper yield was 60% higher than Inca Bella and independent of soil compaction treatment, whilst compacted soil reduced Inca Bella yield by 30%. Trial 2 increased initial soil resistance from 0.2 MPa to 1.0 MPa. Soil resistance in the compacted treatments increased to similar, cultivar-dependent resistances as trial 1. Maris Piper yield was 12% higher than Inca Bella, but cultivar variation in yield response to compacted soil did not occur. Soil water content, root growth and tuber growth were measured to determine whether these factors could explain cultivar differences in soil resistance. Soil water content was similar between cultivars, thus did not cause soil resistance to vary between cultivars. Root density was insufficient to cause observed increases soil resistance. Finally, differences in soil resistance between cultivars became significant during tuber initiation, and became more pronounced until harvest. Increased tuber biomass volume (yield) of Maris Piper increased estimated mean soil density (and thus soil resistance) more than Inca Bella. This increase seems to depend on initial compaction, as soil resistance did not significantly increase in uncompacted soil. While increased soil resistance caused cultivar-dependent restriction of root density of young plants that was consistent with cultivar variation in yield, tuber growth likely caused cultivar-dependent increases in soil resistance in field trials, which may have further limited Inca Bella yield.
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Affiliation(s)
- Patrick Skilleter
- Lancaster Environment Centre, University of Lancaster, Lancaster, United Kingdom
| | - David Nelson
- Technical Department, Branston Ltd., Lincoln, United Kingdom
| | - Ian C. Dodd
- Lancaster Environment Centre, University of Lancaster, Lancaster, United Kingdom
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Kaiser CF, Perilli A, Grossmann G, Meroz Y. Studying root-environment interactions in structured microdevices. JOURNAL OF EXPERIMENTAL BOTANY 2023:erad122. [PMID: 37042515 PMCID: PMC10353529 DOI: 10.1093/jxb/erad122] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Indexed: 06/19/2023]
Abstract
In negotiating with the environment, plant roots integrate sensory information over space and time, as the basis of decision making in roots under non-uniform conditions. The complexity and dynamic properties of soil across spatial and temporal scales pose a significant technical challenge for research on mechanisms that drive metabolism, growth and development in roots, as well as on inter-organismal networks in the rhizosphere. Synthetic environments, combining microscopic access and manipulation capabilities with soil-like heterogeneity, are needed to elucidate the intriguing tug-of-war that characterises subsurface ecosystems. Microdevices have provided opportunities for innovative approaches to observe, analyse and manipulate plant roots and advanced our understanding of their development, physiology and interactions with the environment. Initially conceived as perfusion platforms for root cultivation under hydroponic conditions, microdevice design has, in recent years, increasingly shifted to better reflect the complex growth conditions in soil. Heterogeneous micro-environments have been created through co-cultivation with microbes, laminar flow-based local stimulation and physical obstacles and constraints. As such, structured microdevices provide an experimental entry point to the complex network behaviour of soil communities.
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Affiliation(s)
- Christian-Frederic Kaiser
- Institute of Cell and Interaction Biology, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
- CEPLAS - Cluster of Excellence on Plant Sciences, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Alessia Perilli
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
| | - Guido Grossmann
- Institute of Cell and Interaction Biology, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
- CEPLAS - Cluster of Excellence on Plant Sciences, Heinrich-Heine-University Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Yasmine Meroz
- School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel
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Shoaib M, Banerjee BP, Hayden M, Kant S. Roots' Drought Adaptive Traits in Crop Improvement. PLANTS (BASEL, SWITZERLAND) 2022; 11:2256. [PMID: 36079644 PMCID: PMC9460784 DOI: 10.3390/plants11172256] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 08/26/2022] [Accepted: 08/26/2022] [Indexed: 11/16/2022]
Abstract
Drought is one of the biggest concerns in agriculture due to the projected reduction of global freshwater supply with a concurrent increase in global food demand. Roots can significantly contribute to improving drought adaptation and productivity. Plants increase water uptake by adjusting root architecture and cooperating with symbiotic soil microbes. Thus, emphasis has been given to root architectural responses and root-microbe relationships in drought-resilient crop development. However, root responses to drought adaptation are continuous and complex processes and involve additional root traits and interactions among themselves. This review comprehensively compiles and discusses several of these root traits such as structural, physiological, molecular, hydraulic, anatomical, and plasticity, which are important to consider together, with architectural changes, when developing drought resilient crop varieties. In addition, it describes the significance of root contribution in improving soil structure and water holding capacity and its implication on long-term resilience to drought. In addition, various drought adaptive root ideotypes of monocot and dicot crops are compared and proposed for given agroclimatic conditions. Overall, this review provides a broader perspective of understanding root structural, physiological, and molecular regulators, and describes the considerations for simultaneously integrating multiple traits for drought tolerance and crop improvement, under specific growing environments.
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Affiliation(s)
- Mirza Shoaib
- Agriculture Victoria, Grains Innovation Park, 110 Natimuk Road, Horsham, VIC 3400, Australia
- School of Applied Systems Biology, La Trobe University, Bundoora, Melbourne, VIC 3083, Australia
| | - Bikram P. Banerjee
- Agriculture Victoria, Grains Innovation Park, 110 Natimuk Road, Horsham, VIC 3400, Australia
| | - Matthew Hayden
- School of Applied Systems Biology, La Trobe University, Bundoora, Melbourne, VIC 3083, Australia
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Bundoora, Melbourne, VIC 3083, Australia
| | - Surya Kant
- Agriculture Victoria, Grains Innovation Park, 110 Natimuk Road, Horsham, VIC 3400, Australia
- School of Applied Systems Biology, La Trobe University, Bundoora, Melbourne, VIC 3083, Australia
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Bundoora, Melbourne, VIC 3083, Australia
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Lucas M, Nguyen LTT, Guber A, Kravchenko AN. Cover crop influence on pore size distribution and biopore dynamics: Enumerating root and soil faunal effects. FRONTIERS IN PLANT SCIENCE 2022; 13:928569. [PMID: 36160999 PMCID: PMC9491155 DOI: 10.3389/fpls.2022.928569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/05/2022] [Indexed: 06/16/2023]
Abstract
Pore structure is a key determinant of soil functioning, and both root growth and activity of soil fauna are modified by and interact with pore structure in multiple ways. Cover cropping is a rapidly growing popular strategy for improving agricultural sustainability, including improvements in pore structure. However, since cover crop species encompass a variety of contrasting root architectures, they can have disparate effects on formation of soil pores and their characteristics, thus on the pore structure formation. Moreover, utilization of the existing pore systems and its modification by new root growth, in conjunction with soil fauna activity, can also vary by cover crop species, affecting the dynamics of biopores (creation and demolition). The objectives of this study were (i) to quantify the influence of 5 cover crop species on formation and size distribution of soil macropores (>36 μm Ø); (ii) to explore the changes in the originally developed pore architecture after an additional season of cover crop growth; and (iii) to assess the relative contributions of plant roots and soil fauna to fate and modifications of biopores. Intact soil cores were taken from 5 to 10 cm depth after one season of cover crop growth, followed by X-ray computed micro-tomography (CT) characterization, and then, the cores were reburied for a second root growing period of cover crops to explore subsequent changes in pore characteristics with the second CT scanning. Our data suggest that interactions of soil fauna and roots with pore structure changed over time. While in the first season, large biopores were created at the expense of small pores, in the second year these biopores were reused or destroyed by the creation of new ones through earthworm activities and large root growth. In addition, the creation of large biopores (>0.5 mm) increased total macroporosity. During the second root growing period, these large sized macropores, however, are reduced in size again through the action of soil fauna smaller than earthworms, suggesting a highly dynamic equilibrium. Different effects of cover crops on pore structure mainly arise from their differences in root volume, mean diameter as well as their reuse of existing macropores.
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Affiliation(s)
- Maik Lucas
- Department of Soil System Science, Helmholtz Centre for Environmental Research – UFZ, Halle, Germany
| | - Linh T. T. Nguyen
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Andrey Guber
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Alexandra N. Kravchenko
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
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11
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Oburger E, Schmidt H, Staudinger C. Harnessing belowground processes for sustainable intensification of agricultural systems. PLANT AND SOIL 2022; 478:177-209. [PMID: 36277079 PMCID: PMC9579094 DOI: 10.1007/s11104-022-05508-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/18/2022] [Indexed: 06/16/2023]
Abstract
Increasing food demand coupled with climate change pose a great challenge to agricultural systems. In this review we summarize recent advances in our knowledge of how plants, together with their associated microbiota, shape rhizosphere processes. We address (molecular) mechanisms operating at the plant-microbe-soil interface and aim to link this knowledge with actual and potential avenues for intensifying agricultural systems, while at the same time reducing irrigation water, fertilizer inputs and pesticide use. Combining in-depth knowledge about above and belowground plant traits will not only significantly advance our mechanistic understanding of involved processes but also allow for more informed decisions regarding agricultural practices and plant breeding. Including belowground plant-soil-microbe interactions in our breeding efforts will help to select crops resilient to abiotic and biotic environmental stresses and ultimately enable us to produce sufficient food in a more sustainable agriculture in the upcoming decades.
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Affiliation(s)
- Eva Oburger
- Department of Forest and Soil Science, Institute of Soil Research, University of Natural Resources and Life Sciences, Konrad Lorenzstrasse 24, 3430 Tulln an der Donau, Austria
| | - Hannes Schmidt
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Christiana Staudinger
- Department of Forest and Soil Science, Institute of Soil Research, University of Natural Resources and Life Sciences, Konrad Lorenzstrasse 24, 3430 Tulln an der Donau, Austria
- Graduate School of Integrated Sciences for Life, Hiroshima University, Kagamiyama 1-7-1, Higashi-Hiroshima, Japan
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12
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Influence of Plants on the Spatial Variability of Soil Penetration Resistance. EKOLÓGIA (BRATISLAVA) 2022. [DOI: 10.2478/eko-2022-0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Soil penetration resistance is an informative indicator to monitor soil compaction, which affects a range of ecological processes in floodplain ecosystems. The aim of the investigation was to reveal the influence of vegetation cover on the spatial variability of penetration resistance of floodplain soils. The study was carried out in the elm oak forest in the floodplain of the Dnipro River (Dniprovsko-Orilsky Nature Reserve, Ukraine). The study of the soil profile morphology was performed in accordance with the guidelines of the field description of soils FAO. The soil penetration resistance was measured in the field using the Eijkelkamp manual penetrometer to a depth of 100 cm at 5-cm intervals within the polygon consisted of 105 sampling points. Vegetation descriptions were made in a 3×3-meter surrounding from each sampling point. The soil penetration resistance was found to regularly increase with increasing depth. The changes in resistance values were insignificant until 25–30 cm depth. After that, there was a sharp increase in penetration resistance up to the depth of 70–75 cm, after which the indicators plateaued. In the three-dimensional aspect, the spatial variation of soil penetration resistance can be fractionated into broad-scale, medium-scale, and fine-scale components. Tree vegetation induces a broad-scale component of soil penetration resistance variations, which embraces the whole soil profile. The herbaceous vegetation induces a medium-scale component, which embraces the upper and middle parts of the soil profile. The fine-scale component is influenced by pedogenic factors.
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G. Viana W, Scharwies JD, Dinneny JR. Deconstructing the root system of grasses through an exploration of development, anatomy and function. PLANT, CELL & ENVIRONMENT 2022; 45:602-619. [PMID: 35092025 PMCID: PMC9303260 DOI: 10.1111/pce.14270] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 05/16/2023]
Abstract
Well-adapted root systems allow plants to grow under resource-limiting environmental conditions and are important determinants of yield in agricultural systems. Important staple crops such as rice and maize belong to the family of grasses, which develop a complex root system that consists of an embryonic root system that emerges from the seed, and a postembryonic nodal root system that emerges from basal regions of the shoot after germination. While early seedling establishment is dependent on the embryonic root system, the nodal root system, and its associated branches, gains in importance as the plant matures and will ultimately constitute the bulk of below-ground growth. In this review, we aim to give an overview of the different root types that develop in cereal grass root systems, explore the different physiological roles they play by defining their anatomical features, and outline the genetic networks that control their development. Through this deconstructed view of grass root system function, we provide a parts-list of elements that function together in an integrated root system to promote survival and crop productivity.
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Affiliation(s)
| | | | - José R. Dinneny
- Department of BiologyStanford UniversityStanfordCaliforniaUSA
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14
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Custódio V, Gonin M, Stabl G, Bakhoum N, Oliveira MM, Gutjahr C, Castrillo G. Sculpting the soil microbiota. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:508-522. [PMID: 34743401 DOI: 10.1111/tpj.15568] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/20/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
Soil is a living ecosystem, the health of which depends on fine interactions among its abiotic and biotic components. These form a delicate equilibrium maintained through a multilayer network that absorbs certain perturbations and guarantees soil functioning. Deciphering the principles governing the interactions within soils is of critical importance for their management and conservation. Here, we focus on soil microbiota and discuss the complexity of interactions that impact the composition and function of soil microbiota and their interaction with plants. We discuss how physical aspects of soils influence microbiota composition and how microbiota-plant interactions support plant growth and responses to nutrient deficiencies. We predict that understanding the principles determining the configuration and functioning of soil microbiota will contribute to the design of microbiota-based strategies to preserve natural resources and develop more environmentally friendly agricultural practices.
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Affiliation(s)
- Valéria Custódio
- Future Food Beacon of Excellence, School of Biosciences, University of Nottingham, Sutton Bonington, Nottingham, UK
| | - Mathieu Gonin
- Future Food Beacon of Excellence, School of Biosciences, University of Nottingham, Sutton Bonington, Nottingham, UK
| | - Georg Stabl
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, Freising, 85354, Germany
| | - Niokhor Bakhoum
- Future Food Beacon of Excellence, School of Biosciences, University of Nottingham, Sutton Bonington, Nottingham, UK
| | - Maria Margarida Oliveira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, Oeiras, 2780-157, Portugal
| | - Caroline Gutjahr
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, Freising, 85354, Germany
| | - Gabriel Castrillo
- Future Food Beacon of Excellence, School of Biosciences, University of Nottingham, Sutton Bonington, Nottingham, UK
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Kemp N, Angelidakis V, Luli S, Nadimi S. How Do Roots Interact with Layered Soils? J Imaging 2022; 8:5. [PMID: 35049846 PMCID: PMC8781602 DOI: 10.3390/jimaging8010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/13/2021] [Accepted: 12/16/2021] [Indexed: 01/25/2023] Open
Abstract
Vegetation alters soil fabric by providing biological reinforcement and enhancing the overall mechanical behaviour of slopes, thereby controlling shallow mass movement. To predict the behaviour of vegetated slopes, parameters representing the root system structure, such as root distribution, length, orientation and diameter, should be considered in slope stability models. This study quantifies the relationship between soil physical characteristics and root growth, giving special emphasis on (1) how roots influence the physical architecture of the surrounding soil structure and (2) how soil structure influences the root growth. A systematic experimental study is carried out using high-resolution X-ray micro-computed tomography (µCT) to observe the root behaviour in layered soil. In total, 2 samples are scanned over 15 days, enabling the acquisition of 10 sets of images. A machine learning algorithm for image segmentation is trained to act at 3 different training percentages, resulting in the processing of 30 sets of images, with the outcomes prompting a discussion on the size of the training data set. An automated in-house image processing algorithm is employed to quantify the void ratio and root volume ratio. This script enables post processing and image analysis of all 30 cases within few hours. This work investigates the effect of stratigraphy on root growth, along with the effect of image-segmentation parameters on soil constitutive properties.
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Affiliation(s)
- Nina Kemp
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK; (N.K.); (V.A.)
| | - Vasileios Angelidakis
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK; (N.K.); (V.A.)
| | - Saimir Luli
- Preclinical In Vivo Imaging Facility, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK;
| | - Sadegh Nadimi
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK; (N.K.); (V.A.)
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Imaging local soil kinematics during the first days of maize root growth in sand. Sci Rep 2021; 11:22262. [PMID: 34782618 PMCID: PMC8593153 DOI: 10.1038/s41598-021-01056-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/14/2021] [Indexed: 11/08/2022] Open
Abstract
Maize seedlings are grown in Hostun sand with two different gradings and two different densities. The root-soil system is imaged daily for the first 8 days of plant growth with X-ray computed tomography. Segmentation, skeletonisation and digital image correlation techniques are used to analyse the evolution of the root system architecture, the displacement fields and the local strain fields due to plant growth in the soil. It is found that root thickness and root length density do not depend on the initial soil configuration. However, the depth of the root tip is strongly influenced by the initial soil density, and the number of laterals is impacted by grain size, which controls pore size, capillary rise and thus root access to water. Consequently, shorter root axes are observed in denser sand and fewer second order roots are observed in coarser sands. In all soil configurations tested, root growth induces shear strain in the soil around the root system, and locally, in the vicinity of the first order roots axis. Root-induced shear is accompanied by dilative volumetric strain close to the root body. Further away, the soil experiences dilation in denser sand and compaction in looser sand. These results suggest that the increase of porosity close to the roots can be caused by a mix of shear strain and steric exclusion.
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Blagodatskaya E, Tarkka M, Knief C, Koller R, Peth S, Schmidt V, Spielvogel S, Uteau D, Weber M, Razavi BS. Bridging Microbial Functional Traits With Localized Process Rates at Soil Interfaces. Front Microbiol 2021; 12:625697. [PMID: 34777265 PMCID: PMC8581545 DOI: 10.3389/fmicb.2021.625697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 09/01/2021] [Indexed: 12/30/2022] Open
Abstract
In this review, we introduce microbially-mediated soil processes, players, their functional traits, and their links to processes at biogeochemical interfaces [e.g., rhizosphere, detritusphere, (bio)-pores, and aggregate surfaces]. A conceptual view emphasizes the central role of the rhizosphere in interactions with other biogeochemical interfaces, considering biotic and abiotic dynamic drivers. We discuss the applicability of three groups of traits based on microbial physiology, activity state, and genomic functional traits to reflect microbial growth in soil. The sensitivity and credibility of modern molecular approaches to estimate microbial-specific growth rates require further development. A link between functional traits determined by physiological (e.g., respiration, biomarkers) and genomic (e.g., genome size, number of ribosomal gene copies per genome, expression of catabolic versus biosynthetic genes) approaches is strongly affected by environmental conditions such as carbon, nutrient availability, and ecosystem type. Therefore, we address the role of soil physico-chemical conditions and trophic interactions as drivers of microbially-mediated soil processes at relevant scales for process localization. The strengths and weaknesses of current approaches (destructive, non-destructive, and predictive) for assessing process localization and the corresponding estimates of process rates are linked to the challenges for modeling microbially-mediated processes in heterogeneous soil microhabitats. Finally, we introduce a conceptual self-regulatory mechanism based on the flexible structure of active microbial communities. Microbial taxa best suited to each successional stage of substrate decomposition become dominant and alter the community structure. The rates of decomposition of organic compounds, therefore, are dependent on the functional traits of dominant taxa and microbial strategies, which are selected and driven by the local environment.
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Affiliation(s)
- Evgenia Blagodatskaya
- Department of Soil Ecology, Helmholtz Centre for Environmental Research, Halle (Saale), Germany
- Agro-Technological Institute, RUDN University, Moscow, Russia
| | - Mika Tarkka
- Department of Soil Ecology, Helmholtz Centre for Environmental Research, Halle (Saale), Germany
- German Centre for Integrative Biodiversity Research Halle–Jena–Leipzig, Leipzig, Germany
| | - Claudia Knief
- Institute of Crop Science and Resource Conservation – Molecular Biology of the Rhizosphere, University of Bonn, Bonn, Germany
| | - Robert Koller
- Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Stephan Peth
- Institute of Soil Science, University of Hannover, Hanover, Germany
| | | | - Sandra Spielvogel
- Department Soil Science, Institute for Plant Nutrition and Soil Science, Christian-Albrechts University Kiel, Kiel, Germany
| | - Daniel Uteau
- Department of Soil Science, Faculty of Organic Agricultural Sciences, University of Kassel, Kassel, Germany
| | | | - Bahar S. Razavi
- Department of Soil and Plant Microbiome, Institute of Phytopathology, Christian-Albrechts-University of Kiel, Kiel, Germany
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Rao S, Armstrong R, Silva-Perez V, Tefera AT, Rosewarne GM. Pulse Root Ideotype for Water Stress in Temperate Cropping System. PLANTS 2021; 10:plants10040692. [PMID: 33916833 PMCID: PMC8067327 DOI: 10.3390/plants10040692] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/01/2021] [Accepted: 04/01/2021] [Indexed: 11/16/2022]
Abstract
Pulses are a key component of crop production systems in Southern Australia due to their rotational benefits and potential profit margins. However, cultivation in temperate cropping systems such as that of Southern Australia is limited by low soil water availability and subsoil constraints. This limitation of soil water is compounded by the irregular rainfall, resulting in the absence of plant available water at depth. An increase in the productivity of key pulses and expansion into environments and soil types traditionally considered marginal for their growth will require improved use of the limited soil water and adaptation to sub soil constrains. Roots serve as the interface between soil constraints and the whole plant. Changes in root system architecture (RSA) can be utilised as an adaptive strategy in achieving yield potential under limited rainfall, heterogenous distribution of resources and other soil-based constraints. The existing literature has identified a “‘Steep, Deep and Cheap” root ideotype as a preferred RSA. However, this idiotype is not efficient in a temperate system where plant available water is limited at depth. In addition, this root ideotype and other root architectural studies have focused on cereal crops, which have different structures and growth patterns to pulses due to their monocotyledonous nature and determinant growth habit. The paucity of pulse-specific root architectural studies warrants further investigations into pulse RSA, which should be combined with an examination of the existing variability of known genetic traits so as to develop strategies to alleviate production constraints through either tolerance or avoidance mechanisms. This review proposes a new model of root system architecture of “Wide, Shallow and Fine” roots based on pulse roots in temperate cropping systems. The proposed ideotype has, in addition to other root traits, a root density concentrated in the upper soil layers to capture in-season rainfall before it is lost due to evaporation. The review highlights the potential to achieve this in key pulse crops including chickpea, lentil, faba bean, field pea and lupin. Where possible, comparisons to determinate crops such as cereals have also been made. The review identifies the key root traits that have shown a degree of adaptation via tolerance or avoidance to water stress and documents the current known variability that exists in and amongst pulse crops setting priorities for future research.
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