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

Location: Soil Dynamics Research

2023 Annual Report

Objectives
1. Evaluate above- and below-ground 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. 1A. Continue treating the Southeastern bermudagrass pasture to determine the effects of atmospheric CO2 level and N fertility management on above- and below-ground responses of the plant/soil systems. 1B. Continue treating the Southeastern bermudagrass pasture to determine the effects of atmospheric CO2 level... 1C. Determine the effects of elevated CO2 on growth and efficacy of herbicidal control of herbicide resistant weed populations important in Southeastern US. 1D. 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. 2A. Determine if alternative growth media (WT and CCR vs PB standard) impact growth and GHG emissions of common ornamental crops. 2B. Assess growth and GHG emissions from a common perennial ornamental grown in standard growth media (PB) supplemented with varying levels of biochar. 2C. 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. 3A. 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. 4A. Determine the best management practice for using FGD gypsum as a bedding for broiler production. 4B. Determine the influence of FGD gypsum vs. poultry litter treatment on reducing ammonia and GHG emissions from poultry litter. 4C. Evaluate the influence of FGD gypsum litter treatments on nutrient composition and P solubility in poultry litter. 5. Develop implement for subsurface band application of poultry litter (and similar solid manures) to improve the sustainability of field-scale manure use for agriculture production systems. 5A. Develop implement which uses pneumatic conveying, for subsurface band application of litter. 5B. Compare performance of an pneumatic conveying implement with performance of an mesh chain conveyoring implement. 6. Develop uses of biochars for improved agronomic and environmental outcomes. Research can include, but is not limited to, developing biomass conversion technologies to engineer biochar for soil nutrient cycling and heavy metals absorption, examining the role of biochar in optimizing soil nutrients and sequester heavy metals in soils using field-scale studies, and developing the best management practices to apply biochar for improving the soil health and maximizing nutrient uptake by plants.

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.

Progress Report
World food stability depends on productive agricultural systems, but environmental concerns must be addressed for these systems to be sustainable. Research at the ARS-USDA National Soil Dynamics Laboratory, Auburn, Alabama, addresses potential impacts of management strategies on plant productivity, soil physicochemical properties [including soil carbon (C)], greenhouse gas (GHG) emissions, and nutrient losses. Global change research examined the impacts of elevated carbon dioxide (CO2) under differing pasture management practices (nitrogen) on C dynamics. Critical information on how pastures potentially mitigate or contribute to climate change through soil C storage and soil CO2 efflux is needed for efficient environmental management of these systems. Within the long-term bermudagrass pasture study, above- and belowground biomass data continue to be collected; soil cores for soil C as well as lysimeter solution samples are also being collected and processed. Additional work will examine how growth and herbicidal control of weeds important to Southeastern US cropping systems are impacted by the rise in atmospheric CO2. Further work will investigate the differential response of various crop cultivars to a changing CO2 environment. A manuscript from the weed research has recently been published and one on the cultivar efforts is under review. ARS research in Auburn, Alabama, is seeking to understand factors affecting trace gas (carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)) efflux from agricultural and horticultural systems. Carbon dioxide efflux from the pasture study is being continually monitored (24 hours per day) using Automated Carbon Efflux Systems (ACES). Trace gas emissions (CO2, N2O, and CH4) are assessed weekly in this system. Gas samples are collected in situ using the static closed chamber method according to USDA’s Greenhouse Gas Reduction Through Agricultural Carbon Enhancement network (GRACEnet) protocols and analyzed using gas chromatography. Soil C data are being collected in the ongoing bermudagrass pasture study. In addition, a long-term evaluation of CO2 efflux (using ACES) from differing horticulture media is ongoing in plots established on an outdoor soil bin. Studies examining the effects of varying amounts of biochar in growth media on growth and trace gas efflux in both annuals (greenhouse) and perennials (outdoor) have been completed and a journal publication submitted. Direct greenhouse gas emissions from a pilot-scale aquaponics (combining aquaculture and hydroponics) system were also examined. Aquaponics has the potential to reduce environmental impacts of plant production by repurposing aquaculture wastewater for hydroponic plant production in greenhouses. Horticultural plants were produced using standard pine bark mix or perlite as growth substrates. A manuscript has recently been published on this work; an additional paper has been accepted and a third is currently under review. Work with growth media will continue, including further research on how supplemental use of biochar will impact growth and trace gas emissions in other ornamental functional groups. Research is continuing on the development of new methodology for an in situ, rapid, non-destructive technique of measuring soil elements based on soil neutron-activation analysis. This work has recently resulted in one journal publication assessing post-irradiation physicochemical effects. In addition, several presentations of this work have been given at numerous national and international conferences. Using this technology, a soil scanning system has been developed called a Mobile Inelastic Neutron Scattering (MINS) system and work on an initiated CRADA continues with a company to commercialize the MINS technology for use as a method to create element distribution maps across a landscape. The significance of this technologies’ impact has resulted in a NSDL team winning both the USDA-ARS Southeast Area Technology Transfer Award and USDA-ARS National Technology Transfer Award. Due to the growing environmental concern regarding organic waste disposal, field, laboratory, and broiler chicken bedding studies were established to develop improved methods to utilize waste products for soil and crop benefits while minimizing environmental degradation. A series of field studies have been initiated in multiple states to evaluate the effects of management practices of fertilizer and poultry litter application methods on crop production, greenhouse gas emissions, and nutrient losses to the environment through surface water runoff. Research has also been initiated to refine management practices for using gypsum to reduce soluble phosphorus losses to the environment. This included, but was not limited to, the evaluation of how different gypsum bedding management practices influence broiler chicken production, ammonia and greenhouse gas emissions, surface water runoff, broiler litter nutrient concentrations, and development of an implement for litter applications. Several publications on these topics have been recently published. Further development of a new prototype field implement for shallow subsurface band application of poultry litter was accomplished. This implement uses mesh chains to convey litter from the implement hopper to the trenchers which place the litter in the soil.

Accomplishments
1. Elevated CO2 and glyphosate effects on herbicide resistant and susceptible Palmer amaranth. Repeated application of herbicides can lead to herbicide resistant weed populations. Elevated CO2 often increases weed growth; however, effects of rising CO2 on herbicide resistant weeds remains largely unknown. Palmer amaranth populations either resistant or susceptible to glyphosate were exposed to ambient or elevated CO2. To simulate plant size that farmers typically encounter, ARS researchers in Auburn, Alabama, exposed plants to CO2 for two weeks when each population was sprayed with glyphosate (0, 0.5x, 1.0x, or 1.5x label rate). Plants were exposed to CO2 levels for an additional two weeks during which time herbicide injury and leaf gas exchange were assessed. Elevated CO2 had little effect except for decreasing stomatal conductance and increasing water use efficiency. Glyphosate resistant plants showed decreased height and herbicide damage, but increased root dry weight, photosynthesis, stomatal conductance, and water use efficiency. In general, increasing rates of glyphosate only affected the susceptible population. Results suggest that rising CO2 is unlikely to affect Palmer amaranth, including control of glyphosate resistant populations.

2. Measurement of soil elements by neutron-gamma analysis. Determination of soil elements is traditionally determined by laboratory analysis which is time consuming and labor intensive since it needs many samples that require extensive preparation before analysis. Neutron-gamma analysis can be an alternative since it is a non-destructive in situ method that is capable of rapidly measuring very large volumes of material relative to traditional methods. One concern centers on post-irradiation effects on soil physicochemical properties during soil C measurement. Results gathered by ARS researchers in Auburn, Alabama, showed that neutron gamma analysis does not impact physicochemical aspects of soil health and, thus, can be used for soil elemental content determinations without additional radiation safety concerns. Neutron-gamma analysis is a safe, useful tool for farmers assessing elemental status of their soils.

3. Direct greenhouse gas emissions (GHG) from a pilot-scale aquaponics system. Agricultural production systems are known to be large contributors to GHG emissions, but little attention has been given to direct emissions from non-traditional production systems such as aquaponics. Aquaponics (combining aquaculture and hydroponics) has the potential to reduce environmental impacts of plant production by repurposing aquaculture wastewater for hydroponic plant production. ARS researchers in Auburn, Alabama, assessed direct GHG emissions from a pilot-scale aquaponics system. Horticultural plants were produced using standard pine bark mix or perlite as growth substrates. Results from plant production showed significant relationships with various selected parameters with pH having a negative correlation with N2O efflux and pine bark averaging higher CO2 efflux values compared to the perlite substrate. Overall, carbon sequestration in plants could offset 40-62% of direct GHG emissions from the aquaponics system. This study provides insight into operational parameters that affect direct GHG emissions from aquaponics systems and provides data to support life cycle assessments.

4. Influence of broiler litter band distance from the crop row on cotton production. Novel technology has been developed to apply broiler litter in bands below the soil surface. This technology has been shown to increase crop yield in multiple studies across the United States. Presently, it is recommended that the subsurface-applied broiler litter should be applied in bands approximately 15 cm from crop rows. However, this is based on recommendations given for liquid inorganic fertilizer. Thus, ARS researchers in Auburn, Alabama, conducted a study to determine the best distance for applying broiler litter in subsurface bands from cotton rows on crop production. Results from this study showed that the greatest benefit was observed when bands were placed 20 cm or less from crop rows.

Review Publications
Tekeste, M., Way, T.R., Birkenholz, W., Brodbeck, S. 2023. Effect of increased deflection tire technology on soil compaction. Journal of the ASABE. 66(1):75-84. https://doi.org/10.13031/ja.14794.
Li, X., Jiang, J., Guoa, J., Mcclung, A.M., Chen, K., Velarca, M.V., Torbert III, H.A., Dou, F. 2023. Effect of nitrogen application rate under organic and conventional systems on rice (Oryza sativa l.) growth, grain yield, soil properties, and greenhouse gas emissions. Journal of Plant Nutrition. 46:167-1649. https://doi.org/10.1080/01904167.2022.2093746.
Watts, D.B., Way, T.R. 2023. Influence of broiler litter band positioning on cotton growth and yield in a Blackland Prairie soil. Agronomy Journal. https://doi.org/10.1002/agj2.21298.
Runion, G.B., Prior, S.A., Durstock, M., Sanz-Saez, A., Price, A.J. 2023. Effects of elevated CO2 on the response of glyphosate resistant and susceptible Palmer amaranth (Amaranthus palmeri S. Wats.) to varying rates of glyphosate. Archives of Agronomy and Soil Science. 69(13):2739-2752. https://doi.org/10.1080/03650340.2023.2173741.
Way, T.R., Kornecki, T.S., Tewolde, H., Watts, D.B. 2022. Soil rut effects on planter performance for cotton in a conservation tillage system. Applied Engineering in Agriculture. 38(6):951-959. https://doi.org/10.13031/aea.15144.
Ulbrich, N.C., Motta, A.C., Magri, E., Prior, S.A., De Albuquerque, C.G., Gavelaki, F., Barbosa, J.Z., Wendling, I., Poggere, G.C. 2023. Accumulation capacity of nickel and zinc in yerba mate cultivated in soils with contrasting parent materials. Biological Trace Element Research. 201:5468–5480. https://doi.org/10.1007/s12011-023-03593-4.
Bartley, P., Erbrick, L., Knotts, M., Watts, D.B., Torbert III, H.A. 2023. Influence of flue gas desulfurization gypsum on phosphorus loss in pine bark substrates. Agriculture. 13:283. https://doi.org/10.3390/agriculture13020283.
Hamid, A., Wilson, A.E., Torbert III, H.A., Wang, D. 2023. Sorptive removal of phosphorus by flue gas desulfurization gypsum in batch and column systems. Chemosphere. 320:138062. https://doi.org/10.1016/j.chemosphere.2023.138062.
Roy, P., Jahromi, H., Rahman, T., Baltrusaitis, J., Hassan, E., Torbert III, H.A., Adhikari, S. 2023. Hydrotreatment of pyrolysis bio-oil and triglyceride blends. Fuel Processing Technology. 245:107753. https://doi.org/10.1016/j.fuproc.2023.107753.
Watts, D.B., Runion, G.B., Dick, W., Gonzalez, J.M., Islam, K., Flanagan, D.C., Fausey, N.R., Vantoai, T.T., Batte, M., Reeder, R., Kost, D., Chen, L., Jacinthe, P. 2023. Influence of gypsum and cover crop on greenhouse gas emissions in soybean cropping systems. Journal of Soil and Water Conservation. 78(2):154-162. https://doi.org/10.2489/jswc.2023.00042.
Kavetskiy, A.G., Yakubova, G.N., Prior, S.A., Torbert III, H.A. 2023. Neutron gamma analysis of soil carbon: post-irradiation physicochemical effects. Environmental Technology & Innovation. 31:103219. https://doi.org/10.1016/j.eti.2023.103219.
Kalvakaalva, R., Prior, S.A., Smith, M., Runion, G.B., Ayipio, E., Blanchard, C., Wall, N., Wells, D., Hanson, T.R., Higgins, B.T. 2022. Direct greenhouse gas emissions from a commercial pilot-scale aquaponics system. Journal of the ASABE. 65(6):1211-1223. https://doi.org/10.13031/ja.15215.
Magri, E., Barbosa, J.Z., Prior, S.A., Valduga, A.T., Motta, A.C. 2023. Glyphosate effects on non-target plants: collateral impacts on elemental composition and growth of yerba mate. Archives of Agronomy and Soil Science . 69(9):1535-1547. https://doi.org/10.1080/03650340.2022.2102610.
Waldrip, H., Thompson, T.N., Koziel, J.A., Watts, D.B., Torbert III, H.A. 2023. Legacy phosphorus in Alabama Hartsells soil after long-term amendment with broiler litter. Journal of Environmental Quality. 52(4):897-906. https://doi.org/10.1002/jeq2.20462.
Islam, K.R., Dick, W.A., Watts, D.B., Gonzalez, J.M., Fausey, N.R., Flanagan, D.C., Reeder, R.C., Vantoai, T.T., Batte, M.T. 2022. Gypsum, crop rotation, and cover crop impacts on soil organic carbon and biological dynamics in rainfed transitional no-till corn-soybean systems. PLOS ONE. 17(9). Article e0275198. https://doi.org/10.1371/journal.pone.0275198.
Singh, R., Prasad, R., Balkcom, K.S., Lamba, J., Watts, D.B. 2023. Broiler litter application rate and time impacts on corn ear mineral composition. Agronomy Journal. 115:932-944. https://doi.org/10.1002/agj2.21292.
Rieke, E.L., Bagnall, D.K., Morgan, C., Greub, K., Bean, G.M., Cappellazzi, S.B., Cope, M., Liptzin, D., Norris, C.E., Tracy, P.W., Ashworth, A.J., Baumhardt, R.L., Dell, C.J., Derner, J.D., Ducey, T.F., Fortuna, A., Kautz, M.A., Kitchen, N.R., Leytem, A.B., Liebig, M.A., Moore Jr., P.A., Osborne, S.L., Owens, P.R., Sainju, U.M., Sherrod, L.A., Watts, D.B., et al. 2022. Evaluation of aggregate stability methods for soil health. Geoderma. 428. Article 116156. https://doi.org/10.1016/j.geoderma.2022.116156.
Tewolde, H., Way, T.R., Buehring, N., Jenkins, J.N. 2022. Fertilizer value of poultry litter applied by subsurface band vs. surface broadcast in corn production. Journal of Plant Nutrition. 46(9):2044-2059. https://doi.org/10.1080/01904167.2022.2118133.
Zucon, A.S., Pedreira, G.Q., Motta, A.C., Gotz, L.F., Maeda, S., Bassaco, M.V., Magri, E., Prior, S.A., Souza, L., De Oliveira Jr, J.C. 2022. Piling secondary subtropical forest residue: long-term impacts on soil, trees, and weeds. Forests. 13:1183. https://doi.org/10.3390/f13081183.
Kumar, H., Srivastava, P., Lamba, J., Ortiz, B., Way, T.R., Sangha, L., Takhellambam, B., Morata, G., Molinari, R. 2022. Within-field variability in nutrients for site-specific agricultural management in irrigated cornfield. Journal of the ASABE. 65(4):865-880. https://doi.org/10.13031/ja.15042.
Jjagwe, P., Tekeste, M., Alkhalifa, N., Way, T.R. 2023. Modeling tire-soil compression resistance on artificial soil using the scaling law of pressure-soil sinkage relationship. Journal of Terramechanics. 108:7-19. https://doi.org/10.1016/j.jterra.2023.02.002.