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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Research Project #441163

Research Project: Sustaining Productivity and Ecosystem Services of Agricultural and Horticultural Systems in the Southeastern United States

Location: Soil Dynamics Research

Project Number: 6010-11120-009-000-D
Project Type: In-House Appropriated

Start Date: Sep 14, 2021
End Date: Sep 13, 2026

Objective:
1. Evaluate above- and belowground fluxes of C and N to improve pasture and cropping systems management for future climate conditions, including their ability to mitigate climate change via sequestration of CO2. 1.A. Continue treating the Southeastern bermudagrass pasture to determine the effects of atmospheric CO2 level and N fertility management on above- and belowground responses of the plant/soil system. 1.B. Continue treating the Southeastern bermudagrass pasture to determine the effects of atmospheric CO2 level and N fertility management on soil flux of trace gases (CO2, N2O, CH4). 1.C. Determine the effects of elevated CO2 on growth and efficacy of herbicidal control of herbicide resistant weed populations important in Southeastern US cropping systems. 1.D. Identify crop cultivars that respond most favorably to elevated CO2 in terms of growth, yield, and seed nutritional quality. 2. Develop new practices and technologies to quantitatively improve the sustainability of ornamental horticulture systems, including both nursery production and landscaping applications, by reducing greenhouse gas emissions and increasing C sequestration potential. 2.A. Determine if alternative growth media (WT and CCR vs PB standard) impact growth and GHG emissions of common ornamental crops. 2.B. Assess growth and GHG emissions from a common perennial ornamental grown in standard growth media (PB) supplemented with varying levels of biochar. 2.C. Determine the longevity of C in horticultural growth media (e.g., PB standard, CCR, and WT) following placement in the landscape. 3. Develop inelastic neutron scattering technologies for rapid measurement of soil elements to aid in precision application of poultry waste in the landscape. 3.A. Develop new methodology for rapid measurement of soil elements based on soil neutron-activation analysis. 4. Quantify the benefits of flue gas desulfurization (FGD) gypsum when combined with poultry litter to improve the sustainability of full life-cycle poultry production systems. 4.A. Determine the best management practice for using FGD gypsum as a bedding for broiler production. 4.B. Determine the influence of FGD gypsum vs. poultry litter treatment on reducing ammonia concentrations and greenhouse gas emissions from poultry litter. 4.C. Evaluate the influence of FGD gypsum litter treatments on nutrient composition and P solubility in poultry litter. 5. Develop an implement for subsurface band application of poultry litter (and similar solid manures) to quantitatively improve the sustainability of field-scale manure use for row crops, horticultural crops, pastures, or organic production systems. 5.A. Develop a four-band implement which uses pneumatic conveying, for subsurface band application of poultry litter. 5.B. Compare performance of an implement which uses pneumatic conveying for poultry litter subsurface band application, with performance of an implement which uses mesh chain conveyors.

Approach:
A long-term Southeastern bahaigrass pasture study will be terminated and a bermudagrass pasture study will be initiated. Both systems are exposed to current and projected levels of atmospheric CO2 and either managed (N added) or unmanaged (no N). Carbon flux to plants (biomass growth, allocation, and quality) and soil will be determined with supporting data on soil physicochemical properties. Emphasis will be given to measuring soil C and N dynamics and C storage, root growth, water quality, and GHG (CO2, N2O, and CH4) flux from soil. Using the same CO2 levels, container studies on weeds important to the southeastern U.S. (including those resistant to herbicides) will evaluate herbicide efficacy, regrowth, biomass, and tissue quality. In addition, research will evaluate production practices (in terms of such factors as fertilizer placement, growth media, and irrigation) to identify best management practices which ensure productivity, minimize GHG emissions, and maximize belowground C storage. Other work will examine how the application of organic waste to soil can improve soil conditions via C addition and provide nutrients needed for crop production. Poultry litter may be a viable fertilizer option for crop producers in the Southeastern U.S. given the large amounts of manure generated by the poultry industry. However, improper application of animal waste can contribute to environmental degradation such as increased hypoxia, eutrophication, human health problems, and greenhouse gas emissions. Due to these environmental and animal health concerns, studies will be established to develop improved methods to utilize waste products for animal and crop benefits. Research and development of technologies to recover phosphorous from manure, transform manure into secondary byproducts and find alternative, environmentally safe and economical usages of manure will be undertaken. Studies will be initiated to determine long term effects of poultry litter on plant yields, and soil physicochemical properties (including C storage) under various cropping systems. Further, different poultry litter application practices, such as subsurface banding, will be evaluated to determine their impact on nutrient loss and greenhouse gas emissions. Soil amendments (e.g., gypsum) will be evaluated both as a poultry house bedding material and as a soil amendment to determine the impact on animal production, plant responses, and the potential to reduce NH4 emissions and phosphorus (P) loss in runoff. Information acquired in the course of this project will be useful for developing improved poultry and crop production practices. Integrating data from these studies will be economically analyzed to aid understanding on how to adjust future poultry production and agronomic management practices to sustain productivity, while aiding mitigation of global change via increasing soil C sequestration and reducing greenhouse gas emissions.