Location: Adaptive Cropping Systems Laboratory
2022 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
For Objective 4A and 4B we are finishing a manuscript investigating effects of poultry litter on nutrients and heavy metals in soil and vegetation in plots planted to native vegetation, which will be submitted this fiscal year.
Fpr Objective 4C we published a paper on research in watersheds in an urban region which generate runoff and sediments from agricultural and industrial chemicals ending up in the drainage ways. This study estimated the different landforms and patterns of Aldridge Creek Watershed in Alabama and their impact on the water quality and soil properties of the watershed.
For Objective 1A we published a paper that investigated the relative effects of rye, radish, rye/radish combination and triticale on nitrate leaching.
A new Lead scientist, Dr. Eunjin Han was hired this year for this project.
Accomplishments
1. Radish+rye mixtures provided the best protection from nitrogen (N) losses indicating that they are a flexible management tool to reduce leaching losses from cash crop systems. Reduction of N loss from agricultural fields in the Chesapeake Bay Region is critical to eutrophication of the Bay region. One way to achieve this is to plant a rapidly growing grass or other cover crop such as forage radish in the fall, after the main crop is harvested to take up N in the soil. We compared N losses among forage radish, cereal rye, and a forage radish+cereal rye mixture. We found that a mixture of cereal rye and radish had the greatest reduction of N to groundwater throughout the falle, winter and spring. N in the soil water was higher (by 5x) in the soil with no cover crop compared to cover cropped soils. Application of this research on how cover crop species affect N leaching losses can help agricultural managers and growers design cropping systems to minimize N losses to the Chesapeake Bay.
Review Publications
Gaimaro, J., Timlin, D.J., Tully, K. 2021. Comparison of cover crop monocultures and mixtures for suppressing nitrogen leaching losses. Agricultural Water Management. 261:107348. https://doi.org/10.1016/j.agwat.2021.107348.
Jaja, N., Codling, E., Rutto, L., Timlin, D.J., Reddy, V. 2022. Poultry litter and inorganic fertilization: Effect on biomass yield and nutrient concentration of three mixed - season perennial forages. Agronomy Journal. 12:570. https://doi.org/10.3390/agronomy12030570.
Jaja, N., Codling, E.E., Mbila, M., Tsegaye, T.D., Odutola, J. 2022. Landscape variability of riparian buffers and its impact on soil and water chemistry of an urbanized watershed. Ecological Indicators. https://doi.org/10.1016/j.ecolind.2022.108777.
