Location: Agroecosystem Management Research
2024 Annual Report
Objectives
Objective 1: Develop and quantify management strategies that optimize input use in annual and perennial cropping systems, including bioenergy feedstocks, and integrated crop-livestock systems.
Sub-objective 1A: Evaluate the effects of long-term grazing and annual crop management on soil greenhouse gas flux.
Sub-objective 1B: Evaluate nitrogen use and productivity under different carbon amelioration practices.
Sub-objective 1C: Compare grain-based organic cropping management practices on resource use efficiency.
Objective 2: Develop and evaluate crop production systems in the Platte River/High Plains Aquifer region that enhance resilience and productivity under current and projected climate conditions.
Sub-objective 2A: Quantify SOC change on perennial bioenergy feedstocks, pasture, and row crop systems.
Sub-objective 2B: Cover crop evaluation in common and alternative crop rotations.
Sub-objective 2C: Quantify water quality under various crop management systems.
Objective 3: Evaluate greenhouse-gas-neutral agricultural production scenarios and determine key barriers for a circular bioeconomy (Stretch Objective).
Sub-objective 3A: Determine how cropping system diversity impacts greenhouse gas emissions using life-cycle analysis.
Sub-objective 3B: Identify near-term barriers and opportunities for a circular bioeconomy in the central Plains.
Approach
An integrated, systems approach is needed to improve agricultural systems toward greater sustainability and resiliency to meet societal demands for food, feed, fiber, and fuel (Figure 1). Soil and crop management strategies that optimize the capacity of cropland and grasslands to store carbon while minimizing greenhouse gas emissions from nitrogen (N) fertilizer and other management practices are required. Further management improvements are needed to adapt to climate variability and extremes, potential water limitations, and increased agricultural productivity demands by a growing, global population. A better understanding of genetics, management, and environmental conditions is desired to improve or maintain critical agroecosystem services. Research activities will develop management strategies that optimize input use in annual and perennial cropping systems (Objective 1), crop production systems in the Platte River/High Plains Aquifer (PR/HPA) region that enhance resilience and productivity under current and projected climate conditions (Objective 2), and evaluate greenhouse-gas-neutral agricultural production scenarios and determine key barriers for a circular bioeconomy (Objective 3). Specific objectives will be accomplished by a combination of field data, process-based model simulations under different climate conditions, and the use of life-cycle analysis (LCA) to determine baseline greenhouse gas emissions (GHG) and potential GHG mitigation in current and alternative agricultural systems. In addition, coordinated research activities will be conducted as part of the Long-Term Agroecosystem Research (LTAR) Network. The overall research impact will be to increase the economic viability and sustainability of our Nation’s food supply and ensure that agricultural lands in the central Plains region provide abundant environmental services and societal benefits.
Progress Report
This is the first reporting year for “Integrated Agricultural Systems for a Resilient Circular Bioeconomy in the Central Plains.” Progress has been made in all three objectives and sub-objectives. For Objective 1, significant progress has been made in collecting soil greenhouse gas fluxes and yield data from cropland and pasture systems. Under Objective 2, significant progress has been made in collecting baseline soil samples from newly established Long-Term Agroecosystem Research experiments. Substantial progress has been made in collecting cover crop and main crop plant data to be used in refining a cover crop decision support tool. For Objective 3, progress is being made to organize existing long-term datasets and integrating existing datasets into a life-cycle inventory database.
Accomplishments
1. Soil sampling tool for accurate, efficient soil property estimates. A significant portion of the world’s carbon is found in soil, bounded in an organic form. This carbon source is called soil organic carbon and is critical to maintaining soil function particularly in agricultural lands. Accurately measuring soil organic carbon and other important soil properties can be challenging and resource intensive at large scales. ARS scientists in Lincoln, Nebraska, along with University of Nebraska-Lincoln colleagues, have developed the Soil Sample Planning Optimizer Tool to reduce the number of samples needed to quantify soil organic carbon and other soil properties while maintaining the accuracy compared with more resource intensive sampling methods. This tool will provide better representation of soil properties in a more cost-effect manner to producers, consultants and government agencies.
2. Crop rotation diversity improves soil resources and mitigates yield losses. How crop rotation diversity affects soil resources and limits grain yield losses under extreme weather conditions is still unclear. ARS scientists in Lincoln, Nebraska, found that crop rotations affected soil organic matter chemistry and that soil organic matter sources were largely microbial in origin. Crop rotation diversification also increased agricultural resilience to adverse climate conditions, particularly drought. Rotational diversification was beneficial to corn at low nitrogen fertilization, indicating enhanced nitrogen use efficiency. Crop rotation diversity promotes soil nitrogen cycling and can decrease the dependency on external nitrogen inputs while still maintaining crop productivity and decreasing the risk of nitrogen losses into the environment. Results highlight how diverse crop practices can contribute to improved soil health and crop productivity on United States farms.
3. Development of the Cover Crop Decision Support System. Cover crops provide numerous agroecosystem services such as increased soil health and conservation while increasing water and nutrient use efficiency. Cover crop performance depends on cover crop type, climate, soil, and management. ARS researchers in Lincoln, Nebraska, have developed a cover crop decision-making tool for producers to make informed decisions on different aspects of cover crops, particularly, species selection and performance under various climate and management scenarios. The Cover Crop Decision Support System tool enables producers to make informed cover cropping decisions and contributes towards increasing cover crop use.
Review Publications
Birru, G.A., Shiferaw, A., Tadesse, T., Wardlow, B., Jin, V.L., Schmer, M.R., Awada, T., Kharel, T.P., Iqbal, J. 2023. Cover crop performance under a changing climate in continuous corn system over Nebraska. Environmental Quality. 53(1):66-67. https://doi.org/10.1002/jeq2.20526.
Costa, A., Bommarco, R., Smith, M.E., Bowles, T., Guadin, A., Watson, C.A., Berti, A., Blecharczyk, A., Calderon, F.J., Osborne, S.L., Schmer, M.R., et al. 2024. Crop rotational diversity can mitigate climate-induced grain yield losses. Global Change Biology. 30(5). Article 317298. https://doi.org/10.1111/gcb.17298.
Khorchani, M., Awada, T., Schmer, M.R., Jin, V.L., Birru, G.A., Dangal, S.R., Suyker, A., Freidenreich, A.S. 2023. Long-term croplands water productivity in response to management and climate, in Western US corn belt. Agricultural Water Management. 291. Article 108460. https://doi.org/10.1016/j.agwat.2023.108640.
Ramirez II, S., Schmer, M.R., Jin, V.L., Mitchell, R., Stewart, C.E., Parsons, J., Redfearn, D.D., Quinn, J., Varvel, G.E., Vogel, K.P., Follett, R.F. 2024. Perennializing marginal croplands: Going back to the future to mitigate climate change with resilient biobased feedstocks. Frontiers in Energy Research. 11:1-9. https://doi.org/10.3389/fenrg.2023.1272877.
Ramirez II, S., Jin, V.L., Gunderson, L., Schmer, M.R., Hanford, K., Jeske, E., Drijber, R. 2023. No-till marginally mitigates the impact of harvesting stover on soil microbial parameters. Soil Science Society of America Journal. 87(6):348-1364. https://doi.org/10.1002/saj2.20592.
Potash, E., Guan, K., Margenot, A., Lee, D., Boe, A., Douglass, M., Heaton, E., Jang, C., Jin, V.L., Li, N., Mitchell, R., Namoi, N., Schmer, M.R., Wang, S., Zumpf, C. 2023. Multi-site evaluation of stratified and balanced sampling of soil organic carbon stocks in agricultural fields. Geoderma. 438. Article 116587. https://doi.org/10.1016/j.geoderma.2023.116587.