Location: Soil Management and Sugarbeet Research
2020 Annual Report
Objectives
Objective 1: Develop and refine management practices for enhanced yields, nitrogen use efficiencies, carbon sequestration, soil biodiversity and function, and reduced greenhouse gas emissions from agricultural systems of the Great Plains.
Sub-objective 1.1: Improve nutrient (especially nitrogen) management.
Sub-objective 1.2: Reduce greenhouse gas emissions (CO2, N2O, CH4).
Sub-objective 1.3: Characterize soil C and N stocks, fractions, isotopic signatures, and SOC chemistry with depth to develop BMPs that increase C-Seq.
Sub-objective 1.4: Evaluate the effect of management practices on soil microbial structure and function.
Sub-objective 1.5: Increase long-term productivity and economic returns.
Objective 2: Improve procedures for national agricultural greenhouse gas inventories and indices to assess soil biology, soil health, and nutrient management.
Sub-objective 2.1: Develop a new USDA ARS Nutrient Uptake and Outcome (NUOnet) database and improve nutrient indices and tools.
Sub-objective 2.2: Improve procedures and tools for assessment of greenhouse gas emissions (CO2, N2O, CH4), NUE and C-Seq.
Sub-objective 2.3: Develop a new national soil biology database.
Sub-objective 2.4: Develop a new soil biology (soil health) index to quantify beneficial bacteria in soil.
Objective 3: Assess the long-term consequences of management practices and cropping systems on nitrogen use efficiencies, greenhouse gas emissions, carbon sequestration, soil biodiversity and functions.
Sub-objective 3.1: Implement a data management plan and procedures to facilitate data archiving and retrieval in the national databases developed in Objective 2 (NUOnet, GRACEnet, soil biology).
Sub-objective 3.2: Improve long-term nutrient (especially nitrogen) management, while reducing the long-term emissions of greenhouse gases (CO2, N2O, CH4), increasing C-Seq, and enhancing soil health.
Approach
Often the management of agricultural lands has led to degradation of the soil resource, including the depletion of soil carbon and the loss of natural and synthetic nutrients. The lost carbon and nutrients negatively impact producer’s profit margins and have negative environmental impacts (lead to increased buildup of greenhouse gases (GHG) in the atmosphere and pollution of surface and ground water resources). Improved agricultural management can reverse this degradation, improve profit margins and minimize or even mitigate the negative environmental impacts. The overall goal of this project is to develop new and/or improved best management practices (BMPs), new and/or improved models, tools and databases, and sustainable production systems that can help us adapt to and/or mitigate climate change. We will use a combined approach that incorporates field applied studies to develop BMPs (Objective 1); develop and/or improve models, databases, and analytical tools (Objective 2); and conduct field analysis of long-term patterns and processes to assess if the performance of the BMPs is maintained, or improved, over time, and if the models and/or other tools can simulate measured values over decades (Objective 3). The scientific approach includes using different key performance variables of plant productivity such as crop yields; and soil health, nitrogen use efficiency, greenhouse gas emissions, soil carbon sequestration, and soil biological structure and function. A full economic analysis of each BMP will also be conducted. Additionally, basic mechanistic research to increase our knowledge of the basic science and processes of soil chemistry, soil physics, and soil biology, is also being conducted. The Soil Management and Sugar Beet Research Unit scientists have unique skills in each of these fields, and also bring outside collaborators together as part of a comprehensive and multi-faceted research program. As a result of this research, new and viable solutions are developed that address the complexities associated with soil and air management. Tools and information are provided to producers, land managers, and policy makers helping to ensure productive and healthy soils, climate change mitigation and adaptation, and improved air and water quality. Farm sustainability and profitability are improved while improving conservation and minimizing negative environmental impact.
Progress Report
Objective 1. Studies about how management practices impact long-term agricultural productivity of the Great Plains continue. Studies on increasing the sustainability of these systems to sequester soil carbon, reduce greenhouse gas emissions, increase nitrogen use efficiencies and economic returns, prevent soil/water degradation, enhance yields, and maintain soil biology continue to be conducted. Various nitrogen management strategies related to 4R (right time, source, type, rate) are being evaluated. The use of other best management strategies such as cover crops, crop residue management, and tillage practices that minimize soil disturbance is also being monitored. The development of alternative cropping systems as management practices (e.g., polycrops, sorghum sudangrass, and other rotations) is being assessed. These studies are providing information about how to improve long term management of cropping systems to be more sustainable with higher yields and higher nutrient use efficiencies.
Objective 2. Database consolidation continues with increased data handling capacity, data visualization, on-the-fly-analysis, and site data uploads. Data from the Greenhouse gas Reduction through Agricultural Carbon Enhancement network (GRACEnet) and Nutrient Uptake and Outcome network (NUOnet) have been incorporated into the Agricultural Collaborative Research Outcomes System (AgCROS), which also includes information from related ARS projects - Resilient Economic Agricultural Practices (REAP), Long Term Agroecosystem Research (LTAR), Agricultural Antibiotic Resistance (AgAR), and other networks. Publicly available GRACEnet data include crop yield, soil carbon, greenhouse gas (GHG) emission, land management, weather, and other information from 33 field sites across the U.S. with some studies beginning in the 1980s. In addition to observational data, the system now also generates maps of nitrous oxide (N2O) emissions based on the USDA GHG inventory for major crop types across the U.S. Long term harvested biomass, soil carbon stock, and nitrous oxide emissions data from studies in Colorado and other regions continue to be collected to improve and evaluate the DayCent (Daily CENTURY) model and perform meta analyses. NUOnet datasets from 10 additional sites have been aligned this year, in addition to the previous 11 NUOnet field sites released in fiscal year 2019. The soil biology system (myPhyloDB) has been optimized to increase the speed for all data uploading and handling procedures. Several new univariate and multivariate analyses have also been added. Hundreds of soil samples from the USDA Natural Resources Conservation Service Soil Health Assessment Initiative have been received and have been analyzed for microbial community composition and beneficial gene abundance. These samples, in addition to nearly 1000 samples from ongoing research projects analyzed under this research project, are being used to develop indicator curves for selected beneficial genes (e.g., nitrogen fixation) and a general molecular assessment of soil health.
Objective 3. Long-term studies were monitored at Colorado State University. Field sampling of nitrogen fertilization, no-tillage, and organic matter addition studies was completed for the 2019 field year, and laboratory analyses are in progress. Long-term data analyses are in progress. It was found that when deep soil carbon under long-term no-tillage was compared to strip tillage, although strip tillage improved yield by 13%, soil carbon was lost, even with low-impact tillage. Laboratory analyses for field sampling of nitrogen fertilization, no-tillage, and organic matter addition studies are underway. Data analysis continues on the impact of residue removal on soil microbial communities and soil carbon fractions. Studies on the long-term effects on soil biological diversity and function, greenhouse gas emissions, carbon sequestration, nitrogen use efficiencies, and macro- and micro-nutrient dynamics are being conducted. Long-term studies found that manure applications increased crop quality compared to inorganic nitrogen fertilizer application. Manure increased grain concentrations of nutrients such as nitrogen, phosphorous, potassium and magnesium, which are important elements in animal nutrition. These studies found that management practices that maintain or improve soil health and nutrient availability also improve maize productivity and nutritional quality, which could have cascading positive impacts on animal and human nutrition. The studies show that conservation agriculture practices are good alternatives to traditional practices to increase the sustainability of these irrigated farming systems.
Accomplishments
1. Model development and improvement for national greenhouse gas (GHG) inventories and decision support tools. The most substantial improvement to DayCent (Daily CENTURY) is representing the nitrogen (N) cycle with freeze-thaw effects on soil nitrous oxide (N2O) emissions. ARS researchers in Fort Collins, Colorado, collaborated with Colorado State University partners to perform calibration with high frequency N2O observations from gas flux towers and validated with observations from additional experimental sites. Other improvements include representing soil organic matter dynamics to 30 cm depth (previously 20 cm), addressing the effect of cover crops on GHG emissions and removals, better resolving the timing of tillage, planting, fertilization and harvesting based on the USDA-Natural Resources Conservation (NRCS) Conservation Effects Assessment Project (CEAP) survey and state level information on planting and harvest dates; improving the timing of irrigation; and crop senescence using growing degree relationships. These changes resulted in an average increase in emissions of 22 percent from 1990 to 2017 relative to the previous inventory. Additionally, researchers contributed the development of the interactive Carbon Reduction Potential Evaluation Tool (CaRPE ToolTM) that couples cropland and grazing land data from the Ag Census (USDA-National Agricultural Statistics Service) with county-level GHG emission reduction coefficients reported in COMET-Planner for the U.S. Data from the CaRPE Tool has been used by American Farmland Trust in sworn testimony before the congressional House Select Committee on the Climate Crisis to explore the potential role of agriculture in reducing GHG emissions and combating climate change. State summary reports outline GHG mitigation potentials due to conservation practice adoption have been transferred to several Non-Governmental Organization partners (U.S. Climate Alliance, The Nature Conservancy) and 23 state agricultural departments to help prioritize conservation practice implementation in agriculture.
2. Management controls the net greenhouse gas outcomes. Bio-based energy is key to developing a globally sustainable low-carbon economy. Lignocellulosic feedstock production on marginally productive croplands is expected to provide substantial climate mitigation benefits, but long-term field research comparing greenhouse gas (GHG) and soil carbon (C) sequestration during the production of annual versus perennial crop-based feedstocks is lacking. ARS researchers at Fort Collins, Colorado, in collaboration with researchers at the Natural Resources Conservation Service (NRCS), showed that soil C storage in perennial switchgrass (Panicum virgatum L.) and no-tillage continuous corn (Zea mays L.) mitigated GHG emissions on marginal land. However, soil nitrous oxide emissions were controlled by nitrogen (N) fertilizer rate and ultimately determined net agronomic GHG outcomes. National and international modelling efforts of the USDA and Environmental Protection Agency used this data to verify greenhouse gas accounting methods. These data are critical in developing ecosystem service markets and paying producers to reduce environmental impacts.
3. Nitrogen tools can be used to evaluate the effects of management practices. ARS scientists in Fort Collins, Colorado, led the development of nitrogen management tools such as the Nitrogen Index and the new Nitrogen Loss and Environmental Assessment Package (NLEAP) with Geographic Information Systems (GIS) 5.0. The nitrogen management tools have been downloaded over 3,000 times from over 90 countries and are being used by peers from universities, national and international organizations, nutrient managers, conservationists, and others. Surveys of users of the nitrogen tools have found that these tools have been used for assessments of the effects of nitrogen management on nitrogen use efficiencies or nitrogen losses and/or to develop and implement nitrogen management practices, and/or to develop or implement policy across over 96 million acres (over 39 million hectares) covering over 12 million farms. Additionally, professors (national and international) reported that the Nitrogen Index software tool has been used as a teaching tool for undergraduate and graduate students and other technical personnel (over 1,900 students; and over 750 professors, crop consultants, or other professional peers). The software codes for the new NLEAP GIS 5.0 and the Nitrogen Index tools were released to the public. There were over 100 downloads of these tools and/or the respective software codes during fiscal year 2020. The surveys found that during fiscal year 2020 the tools were used for assessment of nitrogen management practices over 10 million hectares (over 25 million acres) covering millions of farms.
4. Conservation agriculture increases profits in an Andean region of South America. The Andean region of South America is critical for the food security and the economy of the surrounding area. Across the Andean region, soils are being cultivated intensively, crop residue is being harvested to feed animals, and erosion is contributing to degradation of soils on steep slopes that receive significant amounts of precipitation. An ARS scientist in Fort Collins, Colorado, in cooperation with U.S. Agency for International Development (USAID) and Virginia Tech, conducted long-term studies in the Andean region of Ecuador assessing the potential of conservation agriculture, using surface water deviation ditches, reduced tillage, residue retention, and application of nitrogen (N), all within an improved rotation. These long-term studies found that conservation agriculture increases yields and saves on production costs due to less tillage. They also found that N fertilization with these conservation agriculture practices increases yields and net economic returns. The studies show that conservation agriculture practices are good alternatives to traditional practices for these high-altitude Andean soils to increase sustainability and economic returns for farmers. These practices could potentially increase the income of 200,000 small farmers in the region.
Review Publications
Feng, Y., Han, S., Chen, W., Gu, Y., Stewart, C.E., Zhang, J., Geng, S., Chen, Z., Setala, H. 2019. Variation of plant communities affect the aggregate protection of lignin in five successional stages of mixed broadleaf-Korean pine forests. Soil Science Society of America Journal. https://doi.org//10.1002/saj2.20032.
Chen, M., Parton, W.J., Hartman, M.D., Del Grosso, S.J., Smith, W.K., Knapp, A.K., Lutz, S., Derner, J.D., Tucker, C.J., Ojima, D.S., Volesky, J., Stephenson, M., Schacht, W., Gao, W. 2019. Assessing precipitation, evapotranspiration, and NDVI as controls of Great Plains plant production. Ecosphere. 10(10):e02889. https://doi.org/10.1002/ecs2.2889.
Degaspari, I.A.M., Soares, J.R., Montezano, Z.F., Del Grosso, S.J., Vitti, A.C., Rossetto, R., Cantarella, H. 2020. Nitrogen sources and application rates affect emissions of N2O and NH3 in sugarcane. Nutrient Cycling in Agroecosystems. https://doi.org//10.1007/s10705-019-10045-w.
Delgado, J.A., Short, N.M., Roberts, D.P., Vandenberg, B.C. 2019. Big data analysis for sustainable agriculture. Frontiers in Sustainable Food Systems. https://doi.org/10.3389/fsufs.2019.00054.
Shang, Z., Zhou, F., Smith, P., Saikawa, E., Ciais, P., Chang, J., Tian, H., Del Grosso, S.J., Ito, A., Chen, M., Wang, Q., Cui, X., Castaldi, S., Juszczak, R., Kasimir, A., Magliulo, V., Medinets, S., Medinets, V., Rees, B., Wohlfart, G., Sabbatini, S., Yan, B. 2019. Weakened growth of cropland N2o emissions in China associated with nationwide policy interventions. Global Change Biology. https://doi.org/10.1111/gcb.14741.
Jin, V.L., Schmer, M.R., Stewart, C.E., Mitchell, R., Williams, C.O., Wienhold, B.J., Varvel, G.E., Follett, R.F., Vogel, K.P., Kimble, J. 2019. Management controls the net greenhouse gas outcomes of growing bioenergy feedstocks on marginally productive croplands. Science Advances. 5(12):1-6. https://doi.org/10.1126/sciadv.aav9318.
Miner, G.L., Delgado, J.A., Ippolito, J.A., Stewart, C.E., Manter, D.K., Del Grosso, S.J., Floyd, B.A., D Adamo, R.E. 2020. Assessing manure and inorganic nitrogen fertilization impacts on soil health, crop productivity, and crop quality in a continuous maize agroecosystem. Journal of Soil and Water Conservation. 75(4):481-498. https://doi.org/10.2489/jswc.2020.00148.
Pantigoso, H.A., Manter, D.K., Vivanco, J.M. 2020. Differential effects of phosphorus fertilizer on the rhizosphere microbiome of cultivated and non-cultivated potatoes. Microbial Ecology. 80:169-180. https://doi.org//10.1007/s00248-020-01486-w.
Hamm, A.K., Manter, D.K., Kirkwood, J., Wolfe, L., Cox-York, K., Weir, T. 2019. The effect of hop extract supplementation on weight gain, adiposity and intestinal function in ovariectomized mice. Nutrients. 11(12). https://doi.org//10.3390/nu11123004.
Delgado, J.A., Vandenberg, B.C., Neer, D.L., D Adamo, R.E. 2019. Emerging nutrient management databases and networks of networks will have broad applicability in future machine learning and artificial intelligence applications in soil and water conservation. Journal of Soil and Water Conservation. 74(6):113A-118A. https://doi.org/10.2489/jswc.74.6.113A.
Li, K., Dilegge, M., Minas, L., Hamm, A.K., Manter, D.K., Vivanco, J.M. 2019. Soil sterilization leads to re-colonization of a healthier rhizosphere microbiome. Rhizosphere. 12. Article e100176. https://doi.org/10.1016/j.rhisph.2019.100176.
Delgado, J.A., Ascough II, J.C., Lighthart, N.P., Neer, D.L. 2020. Potential use of a new nitrogen trading tool to assess nitrogen management practices to protect groundwater quality. Computers and Electronics in Agriculture. 169:105195. https://doi.org/10.1016/j.compag.2019.105195.
Follett, R.F., Stewart, C.E., Bradford, J.A., Pruessner, E.G., Sims, P.L., Vigil, M.F. 2020. Long-term pasture management impacts on eolian sand soils in the southern mixed-grass prairie. International Union for Quaternary Research. https://doi.org//10.1016/j.quaint.2020.07.019.
Vargas, V.P., Soares, J.R., Oliveira, B.G., Lourenço, K.S., Martins, A.A., Del Grosso, S.J., do Carmo, J.B., Cantarella, H. 2019. Sugarcane straw, soil temperature and nitrification inhibitor impact N2O emissions from N fertilizer. BioEnergy Research. 12:801-812. https://doi.org//10.1007/s12155-019-10015-8.
Miner, G., Delgado, J.A., Ippolito, J., Stewart, C.E. 2020. Soil health management practices and crop productivity. Agricultural and Environmental Letters. https://doi.org/10.1002/ael2.20023.
Barrera, V., Delgado, J.A., Alwang, J., Escudero, L., Cartagena, Y., Dominquez, J., D Adamo, R.E. 2019. Conservation agriculture increases yields and economic returns of potato, forage, and grain systems of the Andes. Agronomy Journal. 111:2747-2753. https://doi.org//10.2134/agronj2019.04.0280.
Delgado, J.A. 2020. Nitrogen (nutrient) trading tool. International Soil and Water Conservation Research. https://doi.org/10.1201/9781003045045-44.
Delgado, J.A. 2020. Nitrogen (nitrate leaching) index. International Soil and Water Conservation Research. https://doi.org/10.1201/9781003045045-43.
