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Costa A, Bommarco R, Smith ME, Bowles T, Gaudin ACM, Watson CA, Alarcón R, Berti A, Blecharczyk A, Calderon FJ, Culman S, Deen W, Drury CF, Garcia Y Garcia A, García-Díaz A, Hernández Plaza E, Jonczyk K, Jäck O, Navarrete Martínez L, Montemurro F, Morari F, Onofri A, Osborne SL, Tenorio Pasamón JL, Sandström B, Santín-Montanyá I, Sawinska Z, Schmer MR, Stalenga J, Strock J, Tei F, Topp CFE, Ventrella D, Walker RL, Vico G. Crop rotational diversity can mitigate climate-induced grain yield losses. Glob Chang Biol 2024; 30:e17298. [PMID: 38712640 DOI: 10.1111/gcb.17298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 03/28/2024] [Accepted: 03/31/2024] [Indexed: 05/08/2024]
Abstract
Diversified crop rotations have been suggested to reduce grain yield losses from the adverse climatic conditions increasingly common under climate change. Nevertheless, the potential for climate change adaptation of different crop rotational diversity (CRD) remains undetermined. We quantified how climatic conditions affect small grain and maize yields under different CRDs in 32 long-term (10-63 years) field experiments across Europe and North America. Species-diverse and functionally rich rotations more than compensated yield losses from anomalous warm conditions, long and warm dry spells, as well as from anomalous wet (for small grains) or dry (for maize) conditions. Adding a single functional group or crop species to monocultures counteracted yield losses from substantial changes in climatic conditions. The benefits of a further increase in CRD are comparable with those of improved climatic conditions. For instance, the maize yield benefits of adding three crop species to monocultures under detrimental climatic conditions exceeded the average yield of monocultures by up to 553 kg/ha under non-detrimental climatic conditions. Increased crop functional richness improved yields under high temperature, irrespective of precipitation. Conversely, yield benefits peaked at between two and four crop species in the rotation, depending on climatic conditions and crop, and declined at higher species diversity. Thus, crop species diversity could be adjusted to maximize yield benefits. Diversifying rotations with functionally distinct crops is an adaptation of cropping systems to global warming and changes in precipitation.
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Affiliation(s)
- Alessio Costa
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Riccardo Bommarco
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Monique E Smith
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Timothy Bowles
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, California, USA
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California Davis, Davis, California, USA
| | - Christine A Watson
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Scotland's Rural College, Aberdeen, UK
| | - Remedios Alarcón
- Agro-environmental Department, Madrid Institute for Rural, Agricultural and Food Research and Development, Alcalá de Henares, Spain
| | - Antonio Berti
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
| | | | - Francisco J Calderon
- Columbia Basin Agricultural Research Center, Oregon State University, Adams, Oregon, USA
| | - Steve Culman
- School of Environment and Natural Resources, Ohio State University, Wooster, Ohio, USA
| | - William Deen
- Department of Plant Agriculture, University of Guelph, Guelph, Ontario, Canada
| | - Craig F Drury
- Harrow Research and Development Centre, Agriculture & Agri-Food Canada, Harrow, Ontario, Canada
| | - Axel Garcia Y Garcia
- Department of Agronomy and Plant Genetics at the Southwest Research and Outreach Center, University of Minnesota, Lamberton, Minnesota, USA
| | - Andrés García-Díaz
- Agricultural and Food Research and Development, Applied Research Department, Madrid Institute for Rural, Alcalá de Henares, Spain
| | - Eva Hernández Plaza
- Department of Plant Protection, National Institute for Agricultural and Food Research and Technology, Spanish National Research Council (INIA-CSIC), Madrid, Spain
| | - Krzysztof Jonczyk
- Department of Systems and Economics of Crop Production, Institute of Soil Science and Plant Cultivation - State Research Institute, Puławy, Poland
| | - Ortrud Jäck
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Luis Navarrete Martínez
- Agro-environmental Department, Madrid Institute for Rural, Agricultural and Food Research and Development, Alcalá de Henares, Spain
| | - Francesco Montemurro
- Research Centre for Agriculture and Environment (CREA-AA), Council for Agricultural Research and Agricultural Economy Analysis, Bari, Italy
| | - Francesco Morari
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, Padova, Italy
| | - Andrea Onofri
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy
| | - Shannon L Osborne
- North Central Agricultural Research Laboratory, USDA-ARS, Brookings, South Dakota, USA
| | - José Luis Tenorio Pasamón
- Environment and Agronomy Department, National Institute for Agricultural and Food Research and Technology, Spanish National Research Council (INIA-CSIC), Madrid, Spain
| | - Boël Sandström
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Inés Santín-Montanyá
- Environment and Agronomy Department, National Institute for Agricultural and Food Research and Technology, Spanish National Research Council (INIA-CSIC), Madrid, Spain
| | - Zuzanna Sawinska
- Department of Agronomy, Poznań University of Life Sciences, Poznań, Poland
| | - Marty R Schmer
- Agroecosystem Management Research Unit, USDA-ARS, Lincoln, Nebraska, USA
| | - Jaroslaw Stalenga
- Department of Systems and Economics of Crop Production, Institute of Soil Science and Plant Cultivation - State Research Institute, Puławy, Poland
| | - Jeffrey Strock
- Department of Soil, Water, and Climate at the Southwest Research and Outreach Center, University of Minnesota, Lamberton, Minnesota, USA
| | - Francesco Tei
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy
| | | | - Domenico Ventrella
- Research Centre for Agriculture and Environment (CREA-AA), Council for Agricultural Research and Agricultural Economy Analysis, Bari, Italy
| | | | - Giulia Vico
- Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Grondin A, Natividad MA, Ogata T, Jan A, Gaudin ACM, Trijatmiko KR, Liwanag E, Maruyama K, Fujita Y, Yamaguchi-Shinozaki K, Nakashima K, Slamet-Loedin IH, Henry A. A Case Study from the Overexpression of OsTZF5, Encoding a CCCH Tandem Zinc Finger Protein, in Rice Plants Across Nineteen Yield Trials. Rice (N Y) 2024; 17:25. [PMID: 38592643 PMCID: PMC11003944 DOI: 10.1186/s12284-024-00705-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 03/29/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND Development of transgenic rice overexpressing transcription factors involved in drought response has been previously reported to confer drought tolerance and therefore represents a means of crop improvement. We transformed lowland rice IR64 with OsTZF5, encoding a CCCH-tandem zinc finger protein, under the control of the rice LIP9 stress-inducible promoter and compared the drought response of transgenic lines and nulls to IR64 in successive screenhouse paddy and field trials up to the T6 generation. RESULTS Compared to the well-watered conditions, the level of drought stress across experiments varied from a minimum of - 25 to - 75 kPa at a soil depth of 30 cm which reduced biomass by 30-55% and grain yield by 1-92%, presenting a range of drought severities. OsTZF5 transgenic lines showed high yield advantage under drought over IR64 in early generations, which was related to shorter time to flowering, lower shoot biomass and higher harvest index. However, the increases in values for yield and related traits in the transgenics became smaller over successive generations despite continued detection of drought-induced transgene expression as conferred by the LIP9 promoter. The decreased advantage of the transgenics over generations tended to coincide with increased levels of homozygosity. Background cleaning of the transgenic lines as well as introgression of the transgene into an IR64 line containing major-effect drought yield QTLs, which were evaluated starting at the BC3F1 and BC2F3 generation, respectively, did not result in consistently increased yield under drought as compared to the respective checks. CONCLUSIONS Although we cannot conclusively explain the genetic factors behind the loss of yield advantage of the transgenics under drought across generations, our results help in distinguishing among potential drought tolerance mechanisms related to effectiveness of the transgenics, since early flowering and harvest index most closely reflected the levels of yield advantage in the transgenics across generations while reduced biomass did not.
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Affiliation(s)
- Alexandre Grondin
- Rice Breeding Innovations Department, International Rice Research Institute, Pili Drive, Los Baños, Laguna, Philippines
- Institut de Recherche Pour Le Développement, Université de Montpellier, UMR DIADE, 911 Avenue Agropolis, 34394, Montpellier, France
| | - Mignon A Natividad
- Rice Breeding Innovations Department, International Rice Research Institute, Pili Drive, Los Baños, Laguna, Philippines
| | - Takuya Ogata
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, 305-8686, Japan
| | - Asad Jan
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, 305-8686, Japan
- Institute of Biotechnology and Genetics Engineering, The University of Agriculture, Peshawar, 25130, Khyber Pakhtunkhwa, Pakistan
| | - Amélie C M Gaudin
- Rice Breeding Innovations Department, International Rice Research Institute, Pili Drive, Los Baños, Laguna, Philippines
- Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA
| | - Kurniawan R Trijatmiko
- Rice Breeding Innovations Department, International Rice Research Institute, Pili Drive, Los Baños, Laguna, Philippines
| | - Evelyn Liwanag
- Rice Breeding Innovations Department, International Rice Research Institute, Pili Drive, Los Baños, Laguna, Philippines
| | - Kyonoshin Maruyama
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, 305-8686, Japan
| | - Yasunari Fujita
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, 305-8686, Japan
| | - Kazuko Yamaguchi-Shinozaki
- Biological Resources and Post-Harvest Division, Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, 305-8686, Japan
- Laboratory of Plant Molecular Physiology, The University of Tokyo, Tokyo, 113-8657, Japan
- Tokyo University of Agriculture, Research Institute for Agricultural and Life Sciences, Tokyo, Japan
| | - Kazuo Nakashima
- Food Program, Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, 305-8686, Japan
| | - Inez H Slamet-Loedin
- Rice Breeding Innovations Department, International Rice Research Institute, Pili Drive, Los Baños, Laguna, Philippines
| | - Amelia Henry
- Rice Breeding Innovations Department, International Rice Research Institute, Pili Drive, Los Baños, Laguna, Philippines.
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Jahanzad E, Brewer KM, Poret-Peterson AT, Culumber CM, Holtz BA, Gaudin ACM. Effects of whole-orchard recycling on nitrate leaching potential in almond production systems. J Environ Qual 2022; 51:941-951. [PMID: 35780467 DOI: 10.1002/jeq2.20385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Inefficient nitrogen (N) fertilization and irrigation have led to unhealthy nitrate levels in groundwater bodies of agricultural areas in California. Simultaneously, high commodity prices and drought have encouraged perennial crop growers to turnover less-productive orchards, providing opportunities to recycle tree biomass in situ and to use high-carbon (C) residues to conserve soil and water resources. Although climate change adaptation and mitigation benefits of high-C soil amendments have been shown, uncertainties remain regarding the benefits and trade-offs of this practice for N cycling and retention. We used established almond [Prunus dulcis (Mill.) D. A. Webb] orchard trials on Hanford fine sandy loam with short-term and long-term biomass recycling legacies to better understand the changes in N dynamics and retention capacity associated with this practice. In a soil column experiment, labeled N fertilizer was added and traced into various N pools, including microbial biomass and inorganic fractions in soil and leachate. Shifts in microbial communities were characterized using the abundance of key N cycling functional genes regulating nitrification and denitrification processes. Our findings showed that, in the short term, biomass recycling led to N immobilization within the orchard biomass incorporation depth zone (0-15 cm) without impacts on N leaching potential. However, this practice drastically reduced nitrate leaching potential by 52%, 10 yr after biomass incorporation without an increase in N immobilization. Although the timing of these potential benefits as a function of microbial population and C and N biogeochemical cycles still needs to be clarified, our results highlight the potential of this practice to meaningfully mitigate nitrate discharges into groundwater while conserving soil resources.
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Affiliation(s)
- Emad Jahanzad
- California Department of Food and Agriculture, Sacramento, CA, 95814, USA
| | - Kelsey M Brewer
- Dep. of Plant Sciences, Univ. of California, Davis, CA, 95616, USA
| | | | - Catherine M Culumber
- Division of Agriculture and Natural Recourses, Univ. of California, Davis, CA, 95616, USA
| | - Brent A Holtz
- Division of Agriculture and Natural Recourses, Univ. of California, Davis, CA, 95616, USA
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Wilson H, Daane KM, Maccaro JJ, Scheibner RS, Britt KE, Gaudin ACM. Winter Cover Crops Reduce Spring Emergence and Egg Deposition of Overwintering Navel Orangeworm (Lepidoptera: Pyralidae) in Almonds. Environ Entomol 2022; 51:790-797. [PMID: 35834263 DOI: 10.1093/ee/nvac051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Indexed: 06/15/2023]
Abstract
Habitat diversification has been shown to positively influence a variety of ecosystem services to agriculture, including biological control of arthropod pests. The impact of increased biodiversity tends to be species specific though, and practices therefore need to be developed on a case-by-case basis for each cropping system. In perennial systems, numerous studies have demonstrated that cover crops can have positive impacts on soil quality and other ecosystem services, such as pollination and pest management. However, few studies have focused on the use of cover crops to enhance pest control in almond orchards, especially winter cover crops. The primary pest of almonds in North America is navel orangeworm, Amyelois transitella Walker, which overwinter as larva or pupa on remnant nuts, many of which remain on the orchard soil surface. In the spring, first flight adults subsequently use these remnant nuts as reproductive substrate. An experiment was conducted to evaluate the influence of two distinct winter cover crop mixtures on overwintering mortality and spring egg deposition of A. transitella. Remnant nuts placed into cover crop plots produced fewer adult A. transitella in the spring, suggesting increased overwintering mortality. Additionally, spring egg deposition was reduced on remnant nuts in the cover crops, possibly due to the ground covers interfering with host location and access. In this way, winter cover crops appear to contribute to the reduction of A. transitella populations in the orchard by altering abiotic and physical conditions, although studies to document specific mechanisms are still needed.
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Affiliation(s)
- Houston Wilson
- Department of Entomology, University of California, Riverside, Parlier, CA, USA
| | - Kent M Daane
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA, USA
| | - Jessica J Maccaro
- Department of Entomology, University of California, Riverside, Parlier, CA, USA
| | - Reva S Scheibner
- Department of Entomology, University of California, Riverside, Parlier, CA, USA
| | - Kadie E Britt
- Department of Entomology, University of California, Riverside, Parlier, CA, USA
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California-Davis, Davis, CA, USA
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Isaac ME, Nimmo V, Gaudin ACM, Leptin A, Schmidt JE, Kallenbach CM, Martin A, Entz M, Carkner M, Rajcan I, Boyle TD, Lu X. Crop Domestication, Root Trait Syndromes, and Soil Nutrient Acquisition in Organic Agroecosystems: A Systematic Review. Front Sustain Food Syst 2021. [DOI: 10.3389/fsufs.2021.716480] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Selecting crops that express certain reproductive, leaf, and root traits has formed detectable, albeit diverse, crop domestication syndromes. However, scientific and informal on-farm research has primarily focused on understanding and managing linkages between only certain domestication traits and yield. There is strong evidence suggesting that functional traits can be used to hypothesize and detect trade-offs, constraints, and synergies among crop yield and other aspects of crop biology and agroecosystem function. Comparisons in the functional traits of crops vs. wild plants has emerged as a critical avenue that has helped inform a better understanding of how plant domestication has reshaped relationships among yield and traits. For instance, recent research has shown domestication has led important economic crops to express extreme functional trait values among plants globally, with potentially major implications for yield stability, nutrient acquisition strategies, and the success of ecological nutrient management. Here, we present an evidence synthesis of domestication effects on crop root functional traits, and their hypothesized impact on nutrient acquisition strategies in organic and low input agroecosystems. Drawing on global trait databases and published datasets, we show detectable shifts in root trait strategies with domestication. Relationships between domestication syndromes in root traits and nutrient acquisition strategies in low input systems underscores the need for a shift in breeding paradigms for organic agriculture. This is increasingly important given efforts to achieve Sustainable Development Goal (SDG) targets of Zero Hunger via resilient agriculture practices such as ecological nutrient management and maintenance of genetic diversity.
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Renwick LLR, Kimaro AA, Hafner JM, Rosenstock TS, Gaudin ACM. Maize-Pigeonpea Intercropping Outperforms Monocultures Under Drought. Front Sustain Food Syst 2020. [DOI: 10.3389/fsufs.2020.562663] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There is an urgent need to develop resilient agroecosystems capable of helping smallholder farmers adapt to climate change, particularly drought. In East Africa, diversification of maize-based cropping systems by intercropping with grain and tree legumes may foster productivity and resilience to adverse weather conditions. We tested whether intercropping enhances drought resistance and crop and whole-system yields by imposing drought in monocultures and additive intercrops along a crop diversity gradient—sole maize (Zea mays), sole pigeonpea (Cajanus cajan), maize-pigeonpea, maize-gliricidia (Gliricidia sepium, a woody perennial), and maize-pigeonpea-gliricidia—with and without fertilizer application. We developed and tested a novel low-cost, above-canopy rainout shelter design for drought experiments made with locally-sourced materials that successfully reduced soil moisture without creating sizeable artifacts for the crop microenvironment. Drought reduced maize grain yield under fertilized conditions in some cropping systems but did not impact pigeonpea grain yield. Whole-system grain yield and theoretical caloric and protein yields in two intercropping systems, maize-pigeonpea and maize-gliricidia, were similar to the standard sole maize system. Maize-pigeonepea performed most strongly compared to other systems in terms of protein yield. Maize-pigeonpea was the only intercrop that consistently required less land than its corresponding monocultures to produce the same yield (Land Equivalent Ratio >1), particularly under drought. Despite intercropping systems having greater planting density than sole maize and theoretically greater competition for water, they were not more prone to yield loss with drought. Our results show that maize-pigeonpea intercropping provides opportunities to produce the same food on less land under drought and non-drought conditions, without compromising drought resistance of low-input smallholder maize systems.
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Peterson CA, Bell LW, Carvalho PCDF, Gaudin ACM. Resilience of an Integrated Crop–Livestock System to Climate Change: A Simulation Analysis of Cover Crop Grazing in Southern Brazil. Front Sustain Food Syst 2020. [DOI: 10.3389/fsufs.2020.604099] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Integrated crop–livestock systems are a form of sustainable intensification of agriculture that rely on synergistic relationships between plant and animal system elements to bolster critical agroecosystem processes, with potential impacts on resilience to weather anomalies. We simulated productivity dynamics in an integrated cover crop grazing agroecosystem typical of southern Brazil to gain a better understanding of the impacts of livestock integration on system performance, including future productivity and resilience under climate change. Long-term historical simulations in APSIM showed that the integrated system resulted in greater system-wide productivity than a specialized control system in 77% of simulated years. Although soybean yields were typically lower in the integrated system, the additional forage and livestock production increased total system outputs. Under simulated future climate conditions [representative concentration pathway 8.5 (RCP8.5) scenario from 2020 to 2060], integrated system productivity exceeded specialized system productivity in 95% of years despite declines in average soybean yield and aboveground cover crop biomass production. While the integrated system provided a productivity buffer against chronic climate stress, its resilience to annual weather anomalies depended on disturbance type and timing. This study demonstrates the utility of process-based models for exploring biophysical proxies for resilience, as well as the potential advantages of livestock integration into cropland as a sustainable intensification strategy.
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Schmidt JE, Poret-Peterson A, Lowry CJ, Gaudin ACM. Has agricultural intensification impacted maize root traits and rhizosphere interactions related to organic N acquisition? AoB Plants 2020; 12:plaa026. [PMID: 32665828 PMCID: PMC7333546 DOI: 10.1093/aobpla/plaa026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
Plant-microbe interactions in the rhizosphere influence rates of organic matter mineralization and nutrient cycling that are critical to sustainable agricultural productivity. Agricultural intensification, particularly the introduction of synthetic fertilizer in the USA, altered the abundance and dominant forms of nitrogen (N), a critical plant nutrient, potentially imposing selection pressure on plant traits and plant-microbe interactions regulating N cycling and acquisition. We hypothesized that maize adaptation to synthetic N fertilization altered root functional traits and rhizosphere microbial nutrient cycling, reducing maize ability to acquire N from organic sources. Six maize genotypes released pre-fertilizer (1936, 1939, 1942) or post-fertilizer (1984, 1994, 2015) were grown in rhizoboxes containing patches of 15N-labelled clover/vetch residue. Multivariate approaches did not identify architectural traits that strongly and consistently predicted rhizosphere processes, though metrics of root morphological plasticity were linked to carbon- and N-cycling enzyme activities. Root traits, potential activities of extracellular enzymes (BG, LAP, NAG, urease), abundances of N-cycling genes (amoA, narG, nirK, nirS, nosZ) and uptake of organic N did not differ between eras of release despite substantial variation among genotypes and replicates. Thus, agricultural intensification does not appear to have impaired N cycling and acquisition from organic sources by modern maize and its rhizobiome. Improved mechanistic understanding of rhizosphere processes and their response to selective pressures will contribute greatly to rhizosphere engineering for sustainable agriculture.
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Affiliation(s)
- Jennifer E Schmidt
- Department of Plant Sciences, University of California at Davis, One Shields Avenue, Davis, CA, USA
| | - Amisha Poret-Peterson
- USDA-ARS Crops Pathology and Genetics Research Unit, University of California, Davis, CA, USA
| | - Carolyn J Lowry
- Department of Natural Resources and the Environment, University of New Hampshire, 46 College Road, Durham, NH, USA
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California at Davis, One Shields Avenue, Davis, CA, USA
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Peterson CA, Deiss L, Gaudin ACM. Commercial integrated crop-livestock systems achieve comparable crop yields to specialized production systems: A meta-analysis. PLoS One 2020; 15:e0231840. [PMID: 32379773 PMCID: PMC7205283 DOI: 10.1371/journal.pone.0231840] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 04/01/2020] [Indexed: 11/18/2022] Open
Abstract
Production systems that feature temporal and spatial integration of crop and livestock enterprises, also known as integrated crop-livestock systems (ICLS), have the potential to intensify production on cultivated lands and foster resilience to the effects of climate change without proportional increases in environmental impacts. Yet, crop production outcomes following livestock grazing across environments and management scenarios remain uncertain and a potential barrier to adoption, as producers worry about the effects of livestock activity on the agronomic quality of their land. To determine likely production outcomes across ICLS and to identify the most important moderating variables governing those outcomes, we performed a meta-analysis of 66 studies comparing crop yields in ICLS to yields in unintegrated controls across 3 continents, 12 crops, and 4 livestock species. We found that annual cash crops in ICLS averaged similar yields (-7% to +2%) to crops in comparable unintegrated systems. The exception was dual-purpose crops (crops managed simultaneously for grazing and grain production), which yielded 20% less on average than single-purpose crops in the studies examined. When dual-purpose cropping systems were excluded from the analysis, crops in ICLS yielded more than in unintegrated systems in loamy soils and achieved equal yields in most other settings, suggesting that areas of intermediate soil texture may represent a "sweet-spot" for ICLS implementation. This meta-analysis represents the first quantitative synthesis of the crop production outcomes of ICLS and demonstrates the need for further investigation into the conditions and management scenarios under which ICLS can be successfully implemented.
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Affiliation(s)
- Caitlin A. Peterson
- Department of Plant Sciences, University of California, Davis, CA, United States of America
| | - Leonardo Deiss
- College of Food, Agricultural, and Environmental Sciences, The Ohio State University, Columbus, OH, United States of America
| | - Amélie C. M. Gaudin
- Department of Plant Sciences, University of California, Davis, CA, United States of America
- * E-mail:
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Blundell R, Schmidt JE, Igwe A, Cheung AL, Vannette RL, Gaudin ACM, Casteel CL. Organic management promotes natural pest control through altered plant resistance to insects. Nat Plants 2020; 6:483-491. [PMID: 32415295 DOI: 10.1038/s41477-020-0656-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
Reduced insect pest populations found on long-term organic farms have mostly been attributed to increased biodiversity and abundance of beneficial predators, as well as to changes in plant nutrient content. However, the role of plant resistance has largely been ignored. Here, we determine whether host plant resistance mediates decreased pest populations in organic systems and identify potential underpinning mechanisms. We demonstrate that fewer numbers of leafhoppers (Circulifer tenellus) settle on tomatoes (Solanum lycopersicum) grown using organic management as compared to conventional. We present multiple lines of evidence, including rhizosphere soil microbiome sequencing, chemical analysis and transgenic approaches, to demonstrate that changes in leafhopper settling between organically and conventionally grown tomatoes are dependent on salicylic acid accumulation in plants and mediated by rhizosphere microbial communities. These results suggest that organically managed soils and microbial communities may play an unappreciated role in reducing plant attractiveness to pests by increasing plant resistance.
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Affiliation(s)
- Robert Blundell
- Department of Plant Pathology, University of California, Davis, CA, USA
| | | | - Alexandria Igwe
- Department of Entomology and Nematology, University of California, Davis, CA, USA
| | - Andrea L Cheung
- Department of Plant Pathology, University of California, Davis, CA, USA
| | - Rachel L Vannette
- Department of Entomology and Nematology, University of California, Davis, CA, USA
| | | | - Clare L Casteel
- Department of Plant Pathology, University of California, Davis, CA, USA.
- School of Integrative Plant Science, Plant-Microbe Biology and Plant Pathology Section, Cornell University, Ithaca, NY, USA.
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Li M, Schmidt JE, LaHue DG, Lazicki P, Kent A, Machmuller MB, Scow KM, Gaudin ACM. Impact of Irrigation Strategies on Tomato Root Distribution and Rhizosphere Processes in an Organic System. Front Plant Sci 2020; 11:360. [PMID: 32292412 PMCID: PMC7118217 DOI: 10.3389/fpls.2020.00360] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 03/12/2020] [Indexed: 05/14/2023]
Abstract
Root exploitation of soil heterogeneity and microbially mediated rhizosphere nutrient transformations play critical roles in plant resource uptake. However, how these processes change under water-saving irrigation technologies remains unclear, especially for organic systems where crops rely on soil ecological processes for plant nutrition and productivity. We conducted a field experiment and examined how water-saving subsurface drip irrigation (SDI) and concentrated organic fertilizer application altered root traits and rhizosphere processes compared to traditional furrow irrigation (FI) in an organic tomato system. We measured root distribution and morphology, the activities of C-, N-, and P-cycling enzymes in the rhizosphere, the abundance of rhizosphere microbial N-cycling genes, and root mycorrhizal colonization rate under two irrigation strategies. Tomato plants produced shorter and finer root systems with higher densities of roots around the drip line, lower activities of soil C-degrading enzymes, and shifts in the abundance of microbial N-cycling genes and mycorrhizal colonization rates in the rhizosphere of SDI plants compared to FI. SDI led to 66.4% higher irrigation water productivity than FI, but it also led to excessive vegetative growth and 28.3% lower tomato yield than FI. Our results suggest that roots and root-microbe interactions have a high potential for coordinated adaptation to water and nutrient spatial patterns to facilitate resource uptake under SDI. However, mismatches between plant needs and resource availability remain, highlighting the importance of assessing temporal dynamics of root-soil-microbe interactions to maximize their resource-mining potential for innovative irrigation systems.
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Affiliation(s)
- Meng Li
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Jennifer E. Schmidt
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
| | - Deirdre G. LaHue
- Department of Crop and Soil Sciences, Washington State University, Mount Vernon, WA, United States
| | - Patricia Lazicki
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, CA, United States
| | - Angela Kent
- Department of Natural Resources and Environmental Science, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Megan B. Machmuller
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, United States
- Department of Soil and Crop Science, Colorado State University, Fort Collins, CO, United States
| | - Kate M. Scow
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, CA, United States
| | - Amélie C. M. Gaudin
- Department of Plant Sciences, University of California, Davis, Davis, CA, United States
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Schmidt JE, Kent AD, Brisson VL, Gaudin ACM. Agricultural management and plant selection interactively affect rhizosphere microbial community structure and nitrogen cycling. Microbiome 2019; 7:146. [PMID: 31699148 PMCID: PMC6839119 DOI: 10.1186/s40168-019-0756-9] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 10/02/2019] [Indexed: 05/11/2023]
Abstract
BACKGROUND Rhizosphere microbial communities are key regulators of plant performance, yet few studies have assessed the impact of different management approaches on the rhizosphere microbiomes of major crops. Rhizosphere microbial communities are shaped by interactions between agricultural management and host selection processes, but studies often consider these factors individually rather than in combination. We tested the impacts of management (M) and rhizosphere effects (R) on microbial community structure and co-occurrence networks of maize roots collected from long-term conventionally and organically managed maize-tomato agroecosystems. We also explored the interaction between these factors (M × R) and how it impacts rhizosphere microbial diversity and composition, differential abundance, indicator taxa, co-occurrence network structure, and microbial nitrogen-cycling processes. RESULTS Host selection processes moderate the influence of agricultural management on rhizosphere microbial communities, although bacteria and fungi respond differently to plant selection and agricultural management. We found that plants recruit management-system-specific taxa and shift N-cycling pathways in the rhizosphere, distinguishing this soil compartment from bulk soil. Rhizosphere microbiomes from conventional and organic systems were more similar in diversity and network structure than communities from their respective bulk soils, and community composition was affected by both M and R effects. In contrast, fungal community composition was affected only by management, and network structure only by plant selection. Quantification of six nitrogen-cycling genes (nifH, amoA [bacterial and archaeal], nirK, nrfA, and nosZ) revealed that only nosZ abundance was affected by management and was higher in the organic system. CONCLUSIONS Plant selection interacts with conventional and organic management practices to shape rhizosphere microbial community composition, co-occurrence patterns, and at least one nitrogen-cycling process. Reframing research priorities to better understand adaptive plant-microbe feedbacks and include roots as a significant moderating influence of management outcomes could help guide plant-oriented strategies to improve productivity and agroecosystem sustainability.
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Affiliation(s)
- Jennifer E. Schmidt
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616 USA
| | - Angela D. Kent
- Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, N-215 Turner Hall, MC-047, 1102 S. Goodwin Avenue, Urbana, IL USA
| | - Vanessa L. Brisson
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 USA
- The DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598 USA
| | - Amélie C. M. Gaudin
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616 USA
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Tautges NE, Chiartas JL, Gaudin ACM, O'Geen AT, Herrera I, Scow KM. Deep soil inventories reveal that impacts of cover crops and compost on soil carbon sequestration differ in surface and subsurface soils. Glob Chang Biol 2019; 25:3753-3766. [PMID: 31301684 DOI: 10.1111/gcb.14762] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/19/2019] [Accepted: 06/24/2019] [Indexed: 06/10/2023]
Abstract
Increasing soil organic carbon (SOC) via organic inputs is a key strategy for increasing long-term soil C storage and improving the climate change mitigation and adaptation potential of agricultural systems. A long-term trial in California's Mediterranean climate revealed impacts of management on SOC in maize-tomato and wheat-fallow cropping systems. SOC was measured at the initiation of the experiment and at year 19, at five depth increments down to 2 m, taking into account changes in bulk density. Across the entire 2 m profile, SOC in the wheat-fallow systems did not change with the addition of N fertilizer, winter cover crops (WCC), or irrigation alone and decreased by 5.6% with no inputs. There was some evidence of soil C gains at depth with both N fertilizer and irrigation, though high variation precluded detection of significant changes. In maize-tomato rotations, SOC increased by 12.6% (21.8 Mg C/ha) with both WCC and composted poultry manure inputs, across the 2 m profile. The addition of WCC to a conventionally managed system increased SOC stocks by 3.5% (1.44 Mg C/ha) in the 0-30 cm layer, but decreased by 10.8% (14.86 Mg C/ha) in the 30-200 cm layer, resulting in overall losses of 13.4 Mg C/ha. If we only measured soil C in the top 30 cm, we would have assumed an increase in total soil C increased with WCC alone, whereas in reality significant losses in SOC occurred when considering the 2 m soil profile. Ignoring the subsoil carbon dynamics in deeper layers of soil fails to recognize potential opportunities for soil C sequestration, and may lead to false conclusions about the impact of management practices on C sequestration.
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Affiliation(s)
- Nicole E Tautges
- Agricultural Sustainability Institute, University of California Davis, Davis, California
| | - Jessica L Chiartas
- Department of Land, Air and Water Resources, University of California Davis, Davis, California
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California Davis, Davis, California
| | - Anthony T O'Geen
- Department of Land, Air and Water Resources, University of California Davis, Davis, California
| | - Israel Herrera
- Agricultural Sustainability Institute, University of California Davis, Davis, California
| | - Kate M Scow
- Agricultural Sustainability Institute, University of California Davis, Davis, California
- Department of Land, Air and Water Resources, University of California Davis, Davis, California
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Brisson VL, Schmidt JE, Northen TR, Vogel JP, Gaudin ACM. Impacts of Maize Domestication and Breeding on Rhizosphere Microbial Community Recruitment from a Nutrient Depleted Agricultural Soil. Sci Rep 2019; 9:15611. [PMID: 31666614 PMCID: PMC6821752 DOI: 10.1038/s41598-019-52148-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 10/13/2019] [Indexed: 11/09/2022] Open
Abstract
Maize domestication and breeding have resulted in drastic and well documented changes in aboveground traits, but belowground effects on root system functioning and rhizosphere microbial communities remain poorly understood, despite their critical importance for nutrient and water acquisition. We investigated the rhizosphere microbial community composition and structure of ten Zea mays accessions along an evolutionary transect (two teosinte, three inbred maize lines, and five modern maize hybrids) grown in nutrient depleted soil from a low input agricultural system. Microbial community analysis revealed significant differences in community composition between soil compartments (proximal vs. distal rhizosphere) and between plant genetic groups (teosinte, inbred, and modern hybrid). Only a small portion of the microbial community was differentially selected across plant genetic groups: 3.7% of prokaryotic community members and 4.9% of fungal community members were significantly associated with a specific plant genetic group. Indicator species analysis showed the greatest differentiation between modern hybrids and the other two plant genetic groups. Co-occurrence network analysis revealed that microbial co-occurrence patterns of the inbred maize lines’ rhizosphere were significantly more similar to those of the teosintes than to the modern hybrids. Our results suggest that advances in hybrid development significantly impacted rhizosphere microbial communities and network assembly.
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Affiliation(s)
- Vanessa L Brisson
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA. .,The DOE Joint Genome Institute, Walnut Creek, CA, USA. .,Lawrence Livermore National Laboratory, Livermore, CA, USA.
| | - Jennifer E Schmidt
- Department of Plant Sciences, University of California at Davis, Davis, CA, USA
| | - Trent R Northen
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,The DOE Joint Genome Institute, Walnut Creek, CA, USA
| | - John P Vogel
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,The DOE Joint Genome Institute, Walnut Creek, CA, USA.,Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Amélie C M Gaudin
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,Department of Plant Sciences, University of California at Davis, Davis, CA, USA
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Li M, Peterson CA, Tautges NE, Scow KM, Gaudin ACM. Yields and resilience outcomes of organic, cover crop, and conventional practices in a Mediterranean climate. Sci Rep 2019; 9:12283. [PMID: 31439927 PMCID: PMC6706438 DOI: 10.1038/s41598-019-48747-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 08/08/2019] [Indexed: 11/10/2022] Open
Abstract
Adaptive management practices that maximize yields while improving yield resilience are required in the face of resource variability and climate change. Ecological intensification such as organic farming and cover cropping are lauded in some studies for fostering yield resilience, but subject to criticism in others for their low productivity. We implemented a quantitative framework to assess yield resilience, emphasizing four aspects of yield dynamics: yield, yield stability, yield resistance (i.e., the ability of systems to avoid crop failure under stressful growing conditions), and maximum yield potential. We compared the resilience of maize-tomato rotation systems after 24 years of irrigated organic, cover cropped, and conventional management in a Mediterranean climate, and identified crop-specific resilience responses of tomato and maize to three management systems. Organic management maintained tomato yields comparable to those under conventional management, while increasing yield stability and resistance. However, organic and cover cropped system resulted in 36.1% and 35.8% lower maize yields and reduced yield stability and resistance than the conventional system. Our analyses suggest that investments in ecological intensification approaches could potentially contribute to long-term yield resilience, however, these approaches need to be tailored for individual crops and systems to maximize their benefits, rather than employing one-size-fits-all approaches.
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Affiliation(s)
- Meng Li
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Caitlin A Peterson
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Nicole E Tautges
- Agricultural Sustainability Institute, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Kate M Scow
- Department of Land, Air, and Water Resources, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States.
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Webster E, Gaudin ACM, Pulleman M, Siles P, Fonte SJ. Improved Pastures Support Early Indicators of Soil Restoration in Low-input Agroecosystems of Nicaragua. Environ Manage 2019; 64:201-212. [PMID: 31214771 DOI: 10.1007/s00267-019-01181-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/07/2019] [Indexed: 06/09/2023]
Abstract
Pasture degradation hinders livestock production and ecosystem services that support rural smallholder communities throughout Latin America. Silvopastoral systems, with improved pasture cultivars (especially Brachiaria spp.) and multipurpose trees, offer a promising strategy to restore soils and improve livelihoods in the region. However, studies evaluating the impact of such systems on pasture productivity and soil health under realistic smallholder constraints are lacking. We evaluated the impact of improved pasture grass and tree establishment on a suite of soil health indicators in actively grazed, low-input, farmer-managed silvopastoral systems. In August 2013, paired pasture treatments (improved grass with trees vs. traditional pastures) were established on nine farms with similar land-use histories near Matagalpa, Nicaragua. On each farm, one treatment was left as traditional pasture with naturalized grass (Hyparrhenia rufa), while the adjacent treatment was sown with the improved grass (Brachiaria brizantha cv. Marandu) and planted with tree saplings without fertilizer. In August 2015, we measured standing biomass and a suite of chemical, biological, and physical soil health variables. Improved silvopastoral systems with B. brizantha produced more standing grass biomass and supported higher levels of earthworm populations and permanganate oxidizable carbon (POXC) compared to the traditional control. Correlations suggest that earthworms and POXC were associated with incipient improvements to soil aggregate stability and water holding capacity. We report measurable improvements to soil health just two years following the establishment of improved pasture systems under common smallholder management practices and suggest that these systems, even with minimal fertility inputs, have the potential to enhance regional sustainability.
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Affiliation(s)
- Emily Webster
- Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California Davis, Davis, CA, 95616, USA
| | - Mirjam Pulleman
- Centro Internacional de Agricultura Tropical (CIAT), Soils Research Area, AA, 6713, Cali, Colombia
- Department of Soil Quality, Wageningen University, PO Box 47, 6700, AA, Wageningen, The Netherlands
| | - Pablo Siles
- Centro Internacional de Agricultura Tropical (CIAT), Soils Research Area, Apartado Postal LM-172, Managua, Nicaragua
| | - Steven J Fonte
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, 80523, USA.
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17
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Schmidt JE, Gaudin ACM. What is the agronomic potential of biofertilizers for maize? A meta-analysis. FEMS Microbiol Ecol 2018; 94:4999898. [DOI: 10.1093/femsec/fiy094] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 01/07/2023] Open
Affiliation(s)
- Jennifer E Schmidt
- Department of Plant Sciences, University of California at Davis, 2136 Plant and Environmental Sciences One Shields Avenue, Davis, CA 95616, USA
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California at Davis, 2136 Plant and Environmental Sciences One Shields Avenue, Davis, CA 95616, USA
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18
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Schmidt JE, Gaudin ACM. Toward an Integrated Root Ideotype for Irrigated Systems. Trends Plant Sci 2017; 22:433-443. [PMID: 28262426 DOI: 10.1016/j.tplants.2017.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/23/2017] [Accepted: 02/06/2017] [Indexed: 05/24/2023]
Abstract
Breeding towards root-centric ideotypes can be a relatively quick trait-based strategy to improve crop resource use efficiency. Irrigated agriculture represents a crucial and expanding sector, but its unique parameters require traits distinct from previously proposed rainfed ideotypes. We propose a novel irrigated ideotype that integrates traits across multiple scales to enhance resource use efficiency in irrigated agroecosystems, where resources are concentrated in a relatively shallow 'critical zone'. Unique components of this ideotype include rapid transplant recovery and establishment, enhanced exploitation of localized resource hotspots, adaptive physiological regulation, maintenance of hydraulic conductivity, beneficial rhizosphere interactions, and salinity/waterlogging avoidance. If augmented by future research, this target could help to enhance agricultural sustainability in irrigated agroecosystems by guiding the creation of resource-efficient cultivars.
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Affiliation(s)
- Jennifer E Schmidt
- Department of Plant Sciences, University of California (UC) Davis, Davis, CA 95616, USA
| | - Amélie C M Gaudin
- Department of Plant Sciences, University of California (UC) Davis, Davis, CA 95616, USA.
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19
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Schmidt JE, Bowles TM, Gaudin ACM. Using Ancient Traits to Convert Soil Health into Crop Yield: Impact of Selection on Maize Root and Rhizosphere Function. Front Plant Sci 2016; 7:373. [PMID: 27066028 PMCID: PMC4811947 DOI: 10.3389/fpls.2016.00373] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 03/11/2016] [Indexed: 05/21/2023]
Abstract
The effect of domestication and modern breeding on aboveground traits in maize (Zea mays) has been well-characterized, but the impact on root systems and the rhizosphere remain unclear. The transition from wild ecosystems to modern agriculture has focused on selecting traits that yielded the largest aboveground production with increasing levels of crop management and nutrient inputs. Root morphology, anatomy, and ecophysiological processes may have been affected by the substantial environmental and genetic shifts associated with this transition. As a result, root and rhizosphere traits that allow more efficient foraging and uptake in lower synthetic input environments might have been lost. The development of modern maize has led to a shift in microbiome community composition, but questions remain as to the dynamics and drivers of this change during maize evolution and its implications for resource acquisition and agroecosystem functioning under different management practices. Better understanding of how domestication and breeding affected root and rhizosphere microbial traits could inform breeding strategies, facilitate the sourcing of favorable alleles, and open new frontiers to improve resource use efficiency through greater integration of root development and ecophysiology with agroecosystem functioning.
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Affiliation(s)
- Jennifer E. Schmidt
- Department of Plant Sciences, University of California at DavisDavis, CA, USA
| | - Timothy M. Bowles
- Department of Natural Resources and the Environment, University of New HampshireDurham, NH, USA
| | - Amélie C. M. Gaudin
- Department of Plant Sciences, University of California at DavisDavis, CA, USA
- *Correspondence: Amélie C. M. Gaudin
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Abstract
Numerous transgenes have been reported to increase rice drought resistance, mostly in small-scale experiments under vegetative-stage drought stress, but few studies have included grain yield or field evaluations. Different definitions of drought resistance are currently in use for field-based and laboratory evaluations of transgenics, the former emphasizing plant responses that may not be linked to yield under drought. Although those fundamental studies use efficient protocols to uncover and validate gene functions, screening conditions differ greatly from field drought environments where the onset of drought stress symptoms is slow (2-3 weeks). Simplified screening methods, including severely stressed survival studies, are therefore not likely to identify transgenic events with better yield performance under drought in the target environment. As biosafety regulations are becoming established to allow field trials in some rice-producing countries, there is a need to develop relevant screening procedures that scale from preliminary event selection to greenhouse and field trials. Multilocation testing in a range of drought environments may reveal that different transgenes are necessary for different types of drought-prone field conditions. We describe here a pipeline to improve the selection efficiency and reproducibility of results across drought treatments and test the potential of transgenic rice for the development of drought-resistant material for agricultural purposes.
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Affiliation(s)
- Amélie C M Gaudin
- Crop Environmental Sciences Division, International Rice Research Institute, DAPO Box 7777, Metro Manila 1301, Philippines
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