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

Location: Soil Dynamics Research

2022 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 U.S. 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. Manuscripts from the both the weed and cultivar efforts are undergoing 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. A study assessing effects of growth media on trace gas emissions from annual ornamental plants has been published. Currently, a study examining the effects of varying amounts of biochar in growth media on growth and trace gas efflux in day lilies has been completed. 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 two book chapters describing use of this system in assessing agricultural soils. Work on the measurement of soil chlorine and potassium using neutron gamma analysis have been recently published. In addition, a new patent application has been filed to on new methodology to use this technology in the pavement industry. Using this technology, a soil scanning system has been developed called a Mobile Inelastic Neutron Scattering (MINS) system. A Cooperative Research and Development Agreement (CRADA) has been initiated with a company to commercialize the MINS technology for use as a method to create element distribution maps across a landscape. Because of 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, and broiler litter nutrient concentrations.

Accomplishments
1. 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. ARS researchers in Auburn, Alabama, found that Neutron-gamma analysis can be used to measure total soil potassium (in addition to numerous other elements such as carbon and nitrogen reported previously) and assess soil for chlorine contamination. Neutron-gamma analysis is a useful tool for farmers assessing the nutritional status of their soils, as well as organizations seeking to remediate chlorine contaminated sites.

2. Assessing legume photosynthetic characteristics with leaf spectral reflectance. Future global food demand will require increased agricultural output; rising atmospheric carbon dioxide (CO2) will exacerbate this challenge due to changing climate, temperatures, and drought frequencies. One means of improving future crop yields could be examining identified photosynthetic parameters that vary in response to climate. Direct measurements are very time-consuming but estimates using rapid and non-destructive leaf spectroscopy can overcome this issue. ARS researchers in Auburn, Alabama, examined diverse genotypes of two important legumes (soybean and peanut) under different environments (watering level, atmospheric CO2 level, and night temperature) using advanced regression models to estimate leaf parameters with a field spectroradiometer. Robust model predictions were achieved for photosynthesis parameters indicating that field spectroscopy shows promise for estimating variations in photosynthetic capacity based on leaf and canopy spectral properties.

3. Improving legume crops by co-inoculation with rhizobia and Trichoderma. Inoculation of plants with microorganisms has been shown to improve aspects of growth, yield, and disease resistance. ARS researchers in Auburn, Alabama, have recently, increased the attention placed on assessing the benefits of co-inoculation with more than one microorganism. However, effects of co-inoculation of legumes with rhizobia and Trichoderma still requires detailed analysis and thus a global meta-analysis was conducted. This meta-analysis showed that co-inoculation provided multiple plant benefits compared to inoculation with rhizobia alone. Co-inoculation improved disease control, the root system and nodulation (growth and activity), which contributed to more nitrogen in shoots and grain. Co-inoculation was effective even under contrasting conditions such as variations in legume species, rhizobia genus, Trichoderma species, co-inoculation methods, plant health status, and in both field and pot experiments. In summary, co-inoculation of legumes shows potential for improving economic and environmental aspects of agroecosystems, indicating use should be encouraged as scientific and technological improvement are sought.

4. Influence of flue gas desulfurization (FGD) gypsum on nutrient loss. Nutrients, particularly nitrogen (N) and phosphorus (P), can reduce water quality when entering freshwater systems. It is believed that the horticultural nursery industry contributes to nutrient loss to surface and ground water; therefore, efforts are being made to develop best management practices to reduce these losses. Amending horticultural media with gypsum can potentially reduce P leaching losses from nursery container production. ARS researchers in Auburn, Alabama, have showed that adding flue gas desulfurization (FGD) gypsum to horticultural potting media reduced P losses by approximately 50% regardless of whether a fast or slow released fertilizer was used. The greatest reductions were achieved when gypsum was mixed with the media as opposed to just being placed separate at the base of the container. These findings suggest that gypsum could be used as a management tool to reduce P loss from the horticultural container industry.

5. Soil macropore characterization using X-ray computed tomography (CT) scanning. Water flow through soil is important for providing infiltration to deliver rain and irrigation water to crop roots, and for reducing runoff water. However, this flow can have detrimental environmental effects, as it allows nutrients and other solutes to be transported by subsurface water flow away from the field area to which they are applied. Soil macropores, which are cavities in soil larger than 75 micrometers, strongly affect water flow through soil. Cylindrical soil samples (150 mm diameter and 500 mm depth) were collected by ARS researchers in Auburn, Alabama, from fine sandy loam soil in a pasture field. A medical X-ray computed tomography (CT) scanner was used to scan each soil sample. These results provide quantitative information of different pore size-dependent soil macropore characteristics for various topographical locations and depths in the pasture field. The results are useful in analyzing the movement of water, nutrients, and other solutes in soil, and in promoting the accuracy and usefulness of computer modeling to improve agricultural productivity and reduce environmental contamination.

Review Publications
Yakubova, G.N., Kavetskiy, A.G., Sargsyan, N., Prior, S.A., Torbert III, H.A. 2022. Neutron-gamma soil analysis for digital agriculture. In Shamshiri, R.R., Shafian S., editors. Digital Agriculture, Methods and Applications. Rijeka, Croatia: IntechOpen. https://doi.org/10.5772/intechopen.102128.
Kavetskiy, A.G., Yakubova, G.N., Sargsyan, N., Prior, S.A., Torbert III, H.A. 2021. Neutron stimulated gamma ray measurements for chlorine detection. Inst of Electrical and Electronic Engineers Transactions of Nuclear Science. 68(7):1495-1504. https://doi.org/10.1109/TNS.2021.3086327.
Kavetskiy, A.G., Yakubova, G., Sargsyan, N., Prior, S.A., Torbert III, H.A., Chin, B.A. 2021. Measuring and mapping potassium in agricultural fields using gamma spectroscopy. Inst of Electrical and Electronic Engineers Transactions of Nuclear Science. 68(10):2550-2558. https://doi.org/10.1109/TNS.2021.3109486.
Tewolde, H., Buehring, N., Way, T.R., Feng, G.G., He, Z., Sistani, K.R., Jenkins, J.N. 2021. Yield and nutrient removal of cotton-corn-soybean rotation systems fertilized with poultry litter. Agronomy Journal. 113:5483-5498. https://doi.10.1002/agj2.20857.
Watts, D.B., Runion, G.B., Torbert III, H.A. 2021. Influence of FGD gypsum on P loss from a horticultural growth medium. Horticulturae. 7(7):199. https://doi.org/10.3390/horticulturae7070199.
Bagnall, D.K., Morgan, C.L., Cope, M., Bean, G.M., Cappellazzi, S.B., Greub, K.L., Liptzin, D., Baumhardt, R.L., Dell, C.J., Derner, J.D., Ducey, T.F., Dungan, R.S., Fortuna, A., Kautz, M.A., Kitchen, N.R., Leytem, A.B., Liebig, M.A., Moore Jr, P.A., Osborne, S.L., Sainju, U.M., Sherrod, L.A., Watts, D.B., Ashworth, A.J., Owens, P.R., et al. 2022. Carbon-sensitive pedotransfer functions for plant-available water. Soil Science Society of America Journal. 86(3):612-629. https://doi.org/10.1002/saj2.20395.
Buchaillot, M., Soba, D., Shu, T., Liu, J., Aranjuelo, I., Araus, J.L., Runion, G.B., Prior, S.A., Kefauver, S.C., Sanz-Saez, A. 2022. Estimating peanut and soybean photosynthetic traits using leaf spectral reflectance and advance regression models. Planta. 255:93. https://doi.org/10.1007/s00425-022-03867-6.
Budhathoki, S., Lamba, J., Srivastava, P., Malhotra, K., Way, T.R., Katuwal, S. 2022. Temporal and spatial variability in 3D soil macropore characteristics determined using X-ray computed tomography. Journal of Soils and Sediments. 22:1263-1277. https://doi.org/10.1007/s11368-022-03150-x.
Chakraborty, S., Prasad, R., Watts, D.B., Torbert III, H.A., Kaur, G. 2022. Exploring alternate methods for predicting sorption-desorption parameters for environmental phosphorus loss assessment in poultry litter impacted soils. Journal of Environmental Management. 317(2022):115454. https://doi.org/10.1016/j.jenvman.2022.115454.
Gonzalez, J.M., Dick, W., Islam, K.R., Watts, D.B., Fausey, N.R., Flanagan, D.C., VanToai, T.T., Batte, M.T., Reeder, R.C., Kost, D., Shedekar, V.S. 2022. Gypsum and cereal rye cover crops affect soil chemistry: Trace metals and plant nutrients. Soil Science Society of America Journal. 886:781-794. https://doi.org/10.1002/saj2.20394.
Lin, Y., Watts, D.B., Runion, G.B. 2022. Influence of poultry litter on nutrient availability and fate in plant-soil systems: A meta-analysis. Journal of Soil and Water Conservation. 77(3):230-239. https://doi.org/10.2489/jswc.2022.00043.
Liptzin, D., Norris, C.E., Cappellazzi, S.B., Bean, G.M., Cope, M., Greub, K.L., Rieke, E.L., Tracy, P.W., Aberle, E., Ashworth, A.J., Baumhardt, R.L., Dell, C.J., Derner, J.D., Ducey, T.F., Novak, J.M., Dungan, R.S., 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. 2022. An evaluation of carbon indicators of soil health in long-term agricultural experiments. Soil Biology and Biochemistry. 172. Article 108708. https://doi.org/10.1016/j.soilbio.2022.108708.
Pereira, M., Bassaco, M.V., Motta, A.C., Maeda, S., Prior, S.A., Marques, R., Magri, E., Bognola, I.A., Gomes, J.B. 2023. Influence of industrial forest residue applications on Pinus taeda: soil, litter, growth, nutrition, and wood quality characteristics. New Forests. 54:83-106. https://doi.org/10.1007/s11056-021-09902-w.
Reike, E., Cappellazzi, S.B., Cope, M., Liptzin, D., Bean, G.M., Greub, K.L., Norris, C.E., Tracy, P.W., Aberle, E., Ashworth, A.J., Baumhardt, R.L., Dell, C.J., Derner, J.D., Ducey, T.F., Fortuna, A., Kautz, M.A., Kitchen, N.R., Moore Jr., P.A., Osborne, S.L., Owens, P.R., Sainju, U.M., Sherrod, L.A., Watts, D.B., et al. 2022. Linking soil microbial community structure to potential carbon mineralization: A continental scale assessment of reduced tillage. Soil Biology and Biochemistry. 168. Article 108618. https://doi.org/10.1016/j.soilbio.2022.108618.
Wang, J., Watts, D.B., Meng, Q., Ma, F., Zhang, Q., Zhang, P., Way, T.R. 2022. Influence of soil wetting and drying cycles on soil detachment. AgriEngineering. 4:533-543. https://doi.org/10.3390/agriengineering4020036.
Runion, G. B., Pritchard, S.G., and Prior, S.A. 2020. Leaves: elevated CO2 levels. In Wang Y.Q., editor. The Handbook of Natural Resources, Volume 1, Terrestrial Ecosystems and Biodiversity. 2nd Edition. Boca Raton, FL: CRC Press. p. 299-304. https://doi.org/10.1201/9780429445651-38
Kavetskiy, A.G., Yakubova, G.N., Sargsyan, N., Prior, S.A., Torbert III, H.A. 2022. Neutron-gamma analysis of soil elements. In Staunton S., Xing, B., editors. Encyclopedia of Soils in the Environment: Reference Module in Earth Systems and Environmental Sciences. 2nd Edition. Amsterdam, Netherlands: Elsevier. https://doi.org/10.1016/B978-0-12-822974-3.00017-3.
Budhathoki, S., Lamba, J., Srivastava, P., Malhotra, K., Way, T.R., Katuwal, S. 2021. Using x-ray computed tomography to quantify variability in soil macropore characteristics in pastures. Soil and Tillage Research. 215:105194. https://doi.org/10.1016/j.still.2021.105194.
Quadros, L.P., Ducheiko, H.A., Maeda, S., Prior, S.A., Araujo, E.M., Gomes, J.B., Bognolla, I.A., Soares, M.T., Magri, E., Frigo, C., Kawasaki, A., Motta, A.C. 2021. Effects of wood ash application on tree nutrition and soil dynamics in a Pinus taeda system. Forest Science. 67(5):618-628. https://doi.org/10.1093/forsci/fxab030.
Singh, R., Prasad, R., Delaney, D., Watts, D.B. 2021. Does soybean yield and seed nutrient content change due to broiler litter application? Agronomy. 11(8):1523. https://doi.org/10.3390/agronomy11081523.
Barbosa, J.Z., Hungria, M., Prior, S.A., Moura, M.C., Poggere, G., Motta, A.C. 2022. Improving yield and health of legume crops via co-inoculation with rhizobia and Trichoderma: A global meta-analysis. Applied Soil Ecology. 176:104493. https://doi.org/10.1016/j.apsoil.2022.104493.