Location: Adaptive Cropping Systems Laboratory
2025 Annual Report
Objectives
Objective 1: Develop strategies using cover cropping and biosolids management to mitigate green-house gas (GHG) emissions and improve soil health.
1.A) Evaluate soil carbon (C) sequestration with cover crops to mitigate GHG emissions.
1.B) Evaluate the ability of biosolids management strategies to sequester C and thereby reduce GHG emissions.
Objective 2: Develop strategies for managing fertilizer-N in cropping systems and manure NH3-N in high-residue tillage systems, to improve N-use efficiency and air quality.
2.A) Conduct field crop research with a corn-wheat-soybean rotation to evaluate 15N uptake efficiencies of genetically modified corn, conservation of N by cover crops, and soybean N2 fixation.
2.B) Evaluate and develop best management practices for reducing ammonia volatilization and to estimate ammonia losses from manures.
Objective 3: Improve descriptions of biological mechanisms controlling bioactive P release to soils, and develop improved fate models and conservation practices to enhance P use efficiency.
3.A) Evaluate nutrient conservation practices based on enhanced understanding of rhizosphere microbiology and enzymology that regulate the release of bioactive manure-P and soil-P to crops and soil.
3.B) Evaluate relevance of current algorithms in use to include rhizosphere microbiology and enzymology processes when modeling P behavior and transport in APEX and similar models.
Objective 4: Develop beneficial uses of agricultural, industrial, and municipal byproducts to enhance crop production and reduce risks to the environment from potential contaminants.
4.A) Conduct phytostabilization research using mixtures of organic resources with byproducts and alkaline amendments to achieve functional remediation and revegetation of barren and biologically dead metal contaminated soils.
4.B) Conduct phytoextraction/phytomining research to identify effective plant species and optimize the agronomic productivity of phytoextraction technologies. 4.C) Conduct research and risk evaluation to assess the risks and benefits from use of industrial, municipal and agricultural byproducts to improve crop production and reduce risk to the environment from byproduct constituents.
4.D) Investigate the use of mixtures of organic amendments, limestone byproducts, flue gas desulfurization gypsum and leachable alkalinity to correct subsoil acidity and improve soil fertility.
Approach
Obj. 1A. A replicated six-year field experiment will be completed to evaluate the rate and quantity of carbon sequestrated by winter cover-crops of rye, hairy vetch, and a rye plus hairy vetch mixture, as compared to a traditional no-cover condition. These data will assess and develop agricultural practices for mitigating global warming.
Obj. 1B. Agricultural use of biosolids could improve soil carbon sequestration and thereby reduce greenhouse-gas emissions. Replicated field research will be conducted on plots previously treated with different rates and types of biosolids, to determine if biosolids can increase soil carbon sequestration. Obj. 2A. Labeled nitrogen fertilizer will be used in a corn-wheat-soybean rotation to evaluate nitrogen use efficiencies of genetically modified and non-modified corn, to measure conservation of corn residual fertilizer by winter-wheat, and to estimate nitrogen fixation of double-crop soybeans. Improving nitrogen use efficiency will reduce nitrogen losses to the environment while maintaining profitability.
Obj. 2B. Ammonia volatilization is a major loss of plant-available nitrogen from surface applied manures. A series of wind tunnel field studies will be conducted to evaluate the ability of new high-residue tillage implements to conserve ammonia, but still maintain surface residues to control erosion.
Obj. 3A. Laboratory incubation-fractionation studies will be conducted to mathematically describe phosphorus transformations and availability in manured soils. These results will assess the advantages and disadvantages of adding organicphosphorus turnover to existing models.
Obj. 3B. A critical evaluation of phosphorus transformation and transport modules within existing phosphorus models will be conducted by validation against long-term field and simulated rainfall studies. The evaluation will focus on the use of rhizosphere microbiology and enzymology for modeling phosphorus.
Obj. 4A. Two field locations will be studied using various mixtures of industrial, municipal, and agricultural byproducts to remediate and revegetate barren and heavymetal contaminated soils. The studies will monitor plant yield and composition to assess byproduct performance and possible risks to wildlife. Obj. 4B. Growth chamber and greenhouse research on phyto-mining will use various fertilizer nutrients and topsoil/subsoil combinations to identify plant species and management practices that optimize agronomic productivity and that extract nickel from nickel-rich soils.
Obj. 4C. A two-year field study will be conducted in Appalachia comparing the uptake of nutrients and metals by peanut and wheat from additions of poultry litter, flue gas desulfurization gypsum, and mined gypsum. A risk assessment on the use of flue gas desulfurization gypsum and mined gypsum in U.S. soils will also be done.
Obj. 4D. A greenhouse study will be conducted to evaluate mixtures of organic amendments, limestone byproducts, flue gas desulfurization gypsum, and leachable alkalinity to correct subsoil acidity for alfalfa. Subsoil acidity commonly limits rooting depth in soils across the mid-Atlantic and Southern regions of the U.S..
Progress Report
This research is part of a bridge year of the project 8042-12000-043-000D “Developing Practices for Nutrient and Byproducts to Mitigate Climate Change, Improve Nutrient Utilization, and Reduce Effects on Environment”. The current bridge project was reshaped by focusing on sustainable soil health and cover crop management in the Long Term Agricultural Research (LTAR) network in 2022. New objectives to complete the current bridge project have been approved on an abbreviated timeline (two years) by national program leaders and a new Project Plan will be submitted when the new Action Plan is available. The objectives for the two-year bridge project focus on 1) improving mechanistic models simulating short- and long-term effects of conservation practices on soil health and crop productivity; and 2) quantifying the biological and physical dynamics of the soil biome and the plant response to flooding. In support of Objective 1, long-term effects of conservation practices including cover crops, no-tillage and crop rotations on soil properties and crop yields were investigated using ARS’s crop and soil models and long-term cropping systems experiment data collected from the Long-Term Agroecosystem Research (LTAR) Network sites in Maryland. A manuscript is currently in development. A stochastic weather generator tool has been developed to generate daily weather data for an upcoming crop growing season. This generation is based on seasonal precipitation and temperature forecasts presented in tercile probabilistic format (i.e., probabilities of above, normal, or below normal conditions). The tool will be used for pre- and in-season forecasting of cereal rye biomass to support cover crop management decisions. Validation and analysis are ongoing. Development of Machine Learning (ML) -based cereal rye biomass prediction models (ML-Rye models) was initiated using the U.S. cereal rye winter cover crop growth database. The ML-Rye models will be used as a benchmark to evaluate the performance of ARS’s process-based cereal rye model, RYESIM. The ML-Rye models will be further improved by adopting domain knowledge of RYESIM and by adopting additional information from satellite-measured remote sensing data (e.g., soil moisture and vegetation indices). A collaboration with the ARS scientists in Beltsville, Maryland was continued as part of the NIFA-funded Diverse Rotations Improve Valuable Ecosystem Services (DRIVES) project. A database containing yield and weather data from 21 long-term agricultural field experiments with crop rotation components has been developed. This database will be released publicly with R tools for easy data access and manipulation. A manuscript introducing the database is currently in development. A new process-based wheat model, WHEATSIM was developed to overcome weakness of existing wheat models lacking coherent integration of three critical biological scales: organ-level morphology, plant-level architecture, and field-level biomass. The WHEATSIM takes a next-generation of wheat simulation framework from organ-level morphology to field-level productivity and explicitly integrates organ-, plant- and field-level components to address cross-scale interactions and enhance simulation accuracy and reliability. WHEATSIM will be critical in simulating the effects of diverse crop rotations and will serve as a prototype framework for other cereal crops. A manuscript is currently under development.In support of Objective 2, collection of complete data set on two varieties of cereal rye grass (Aroostook and Guardian) grown under different temperature and moisture conditions. Data collection included growth parameters, chemical uptake and assimilation into biomass, and plant water uptake. This data will be used to validate the existing ARS’s RYESIM model. A manuscript detailing variety response is currently under development.A manuscript, in collaboration with faculty at Louisiana State University AgCenter and University of North Carolina at Pembroke, has been submitted quantifying the impact of plant, insect, and fish based organic fertilizers on surface runoff water quality. Results demonstrated that more frequent precipitation during early establishment stages (up to 21 days post planting) promoted increased total suspended solids and inorganic-nitrogen in runoff regardless of fertilizer source. Fish-, insect-, or plant-based fertilizers produced comparable yields to using ammonium sulfate, while not increasing total suspended solids or inorganic-nitrogen in runoff water samples. A manuscript, in collaboration with Louisiana State University AgCenter faculty, was submitted examining the potential for silica solubilizing bacteria inoculation of rice for improving rice productivity. Inoculation of rice with silica solubilizing bacteria on bagasse (a byproduct of sugarcane processing) resulted in the highest rice grain yield compared to other inoculated media. Results identified regionally specific organisms for the development of seed and soil treatment to improve nutrient uptake and rice production. In collaboration with faculty at Louisiana State University AgCenter, a manuscript was submitted examining warm-season perennial grass production following the establishment of winter annuals. Results indicated that despite increased soil nitrogen concentrations following winter legumes, perennial bermudagrass production did not increase. It was hypothesized that this lack of response was likely related to shifts in the soil microbial community and discrepancies in the timing of nitrogen needs versus nitrogen availability.
A manuscript was submitted quantifying the decomposition and nutrient release rate of mixed cover crops in no-till row crop production in a humid sub-tropical region. Multi-species cover crop mixes produced greater amounts of biomass, increasing nutrient scavenging and release to subsequent cash crops. On average, 50% of nutrients, in particular nitrogen, were released from biomass by 4 weeks post cover crop termination. Soil nitrogen concentrations increased approximately 6 weeks post termination. Of the mixes examined, crimson clover + hairy vetch + radish and cereal rye + hairy vetch resulted in the greatest soil nitrate-nitrogen concentrations compared to all other treatments. Two trials have been established to document the impact of cereal rye residue on soybean growth and soil microbial community response under different moisture and temperature conditions. Data collection will include destructive sampling at key growth stages to examine full plant and soil response following flooding. A robust data set including growth parameters, nutrient content (plant and soil), rye biomass degradation, root distribution and nodule growth, soil microbial community composition and activity will be collected.
Accomplishments
1. Development of a cereal rye cover crop model. Cereal rye is a popular winter cover crop because it helps control weeds, prevents soil erosion, and improves soil health. Until now, there hasn't been a detailed computer simulation model to help manage cereal rye as a cover crop. ARS researchers in Beltsville, Maryland, created a new model of cereal rye growth and development called RYESIM. The RYESIM model can simulate the effects of plant residue from a cereal rye winter cover crop on soil health, soil water contents, and the growth of following cash crops. This model helps researchers and agricultural advisors understand the short- and long-term benefits of using cereal rye as a cover crop and how it impacts soil and crop management.
Review Publications
Bybee-Finley, K.A., Muller, K.E., White, K.E., Bowels, T., Cavigelli, M.A., Han, E., Schomberg, H.H., Snapp, S., Viens, F., Deiss, L. 2024. Rotational complexity increases cropping system yields under poorer growing conditions. One Earth. 7(9):1638-1654. https://doi.org/10.1016/j.oneear.2024.07.008.
Coughlan De Perez, E., Anderson, W., Han, E., Masukwedza, I., Mphonyane, N. 2024. Detectable use of ENSO information on crop production in Southern Africa. Climate Services. 36. Article e100514. https://doi.org/10.1016/j.cliser.2024.100514.
Wang, Z., Timlin, D.J., Thapa, R., Fleisher, D.H., Beegum, S., Han, E., Schomberg, H.H., Mirsky, S.B., Sun, W., Reddy, V., Horton, R., Tully, K. 2025. Process-based vegetative growth model for cereal rye winter cover crop using object-oriented programming and linked-list data structure. Computers and Electronics in Agriculture. 231. Article e109964. https://doi.org/10.1016/j.compag.2025.109964.