Location: Southeast Watershed Research
2022 Annual Report
Objectives
Objective 1. Develop diversified rotational cropping systems for an integrated crop-livestock production system that includes mixed cropping, provide year-round vegetative cover, habitat for arthropod natural enemies and pollinators, and mitigate crop metal toxicity and persistence of antimicrobial resistance.
Sub-objective 1.1. Compare G x E x M effects (where G is taken as crop diversity/rotation – not genetic engineering) on crop productivity and soil and forage quality in a small integrated crop-livestock farming system setting of: 1). An aspirational rotational cropping system that includes summer cotton (Gossypium hirsutum L.), peanut (Arachis hypogaea), summer and winter forages, and a winter oil-rich biofuel feedstock cash crop, in a full year companion cropping system with phosphorus need-based broiler litter fertilization, and reduced tillage under irrigated and dryland conditions (ASP); 2). A business as usual rotational cropping system that includes summer cotton-peanut-corn (Zea mays L.) with a winter rye (Secale cereale) cover crop that is chemically killed and allowed to decompose on the soil surface, with nitrogen need-based broiler litter fertilization, and reduced tillage under irrigated and dryland conditions (BAU-1); and 3). A business as usual rotational cropping system that includes summer cotton-peanut-forage with a winter rye cover crop that is hayed as forage, with nitrogen need-based broiler litter fertilization, and reduced tillage under irrigated and dryland conditions (BAU-2).
Sub-objective1.2. Incorporate native wildflowers in margins of fields in Sub-Objective 1.1 and assess effects on enhancing pest arthropod natural enemies and attracting pollinators.
Objective 2. Develop and test management strategies for an integrated crop-livestock production system that incorporates flue gas desulfurized gypsum (FGDG) with broiler litter (BL) in southeastern cropping systems to reduce phosphorus (P), nitrogen (N) and metals loss in runoff, manage subsoil acidity, and reduce persistence of resistance to antimicrobial agents.
Sub-objective 2.1. Compare the effects of FGDG and FGDG + BL on crop yield; P, N, and metals loss in runoff; subsoil acidity; and SOM composition.
Sub-objective 2.2. Compare the persistence of foodborne pathogens and bacteria with resistance to metals and antibiotics in cropping systems.
Objective 3. Evaluate and quantify farm-level economic and ecosystem services benefits and risks associated with the use of broiler litter, flue gas desulfurized gypsum, and field edge arthropod habitat buffers for southeastern crop-livestock production systems.
Sub-objective 3.1. Develop a five-year multi-practice planning scenarios using a cooperator’s farm (Wilson Farm WF) as a case study that compares net sustainable profit from Objective 1 cropping systems given the producer’s profit versus environmental goals.
Sub-objective 3.2. Forecast cropping systems effects on runoff losses of water, sediment, C, N, P, S, and metals.
Sub-objective 3.3. Integrate producer’s production, profit, and environmental goals to develop land use designs that optimize producer-desired outcomes.
Approach
The overall goal of this project plan is to develop an integrated production system that provides increased flexibility for small-farm crop-livestock producers to diversify their production portfolio by enhancing the sustainability of ecosystem services delivered from landscapes owned or rented by their operation. We will implement plot-scale research to calibrate crop, environmental, geospatial, economic and whole-farm planning models to compare the performance potential of three enterprise scenarios over a five-year planning cycle. Project objectives will focus on six core subsystems affecting the sustainability of small Crop-livestock producers (Soils, Crops and Forages, Landscape, Livestock, Water, and Economic Sustainability).
In Objective 1, plot-scale research under irrigated and dryland conditions will compare the performance of an Aspirational (ASP) full-year companion rotational cropping system that includes peanut, cotton, summer and winter forages, and a winter oil-rich biofuel feedstock, versus Business as usual (BAU)-1 summer peanut-cotton-corn rotation and BAU-2 summer peanut-cotton-forage rotation, both with a winter rye cover crop. Fertility management will include P-based (ASP) versus N-based (BAUs) application of Broiler litter (BL) supplemented with inorganic amendments as indicated by soil testing. All plots will be managed under strip-tillage and include field edge native wildflower habitat to enhance pollination and populations of pest arthropod natural enemies. Seasonal soil and plant sampling and analyses will be used for quantifying GxExM effects on productivity, forage and soil quality, and beneficial insect dynamics.
In objective 2, we will modify an existing three-year plot-scale experiment of continuous summer corn and winter rye conventional tillage system that examined BL and Flue gas desulfurization gypsum (FGDG) effects on P, N, carbon (C) and metals loss in runoff, and yield. The BL and FGDG annual application rates will be reduced by two-thirds for three years followed by three years with no BL and FGDG amendments. Soil cores down to 100 cm were collected at the start and are collected at three-year intervals thereafter for detailed analyses of distribution of nutrients, soil acidity, and metals. We will track nutrient dynamics in the soil, runoff, and plants from residual sources of BL and FGDG. We will also investigate factors influencing persistence of antimicrobial resistance and crop metal toxicities.
In objective 3, data acquired under objectives 1 and 2 will be used to compare farm-level economic and ecosystem services benefits and risks associated with the three cropping systems (ASP + 2BAU). Economic and environmental models will be used to synthesize the five- and ten-year outcomes of each cropping system under four weather and two land use scenarios.
All research within SEWRL is conducted as part of the ARS Long Term Agroecosystem Research (LTAR) Project. This NP 216 Project Plan is intended to augment NP 211 Conservation Effects Assessment Project (CEAP) research on crop-livestock production systems and develop an option suitable for inclusion as an LTAR ASP system.
Progress Report
Objective 1.1. ARS researchers in Tifton, Georgia, successfully completed the third year of fall/winter 2021, and the fourth year of spring 2022 field activities at 48 irrigated and 48 dryland plots at the Belflower Farm. Summer crops and forages are corn, cotton, peanuts, tifleaf3 (millet), and sorghum followed by sun hemp (double crop). Forages are harvested multiple times simulating foraging by cattle. Winter covers include carinata as an oil crop, a rye/black oat mix cover as a soil builder, and rye that is either hayed (simulating grazing) or chemically killed. Fertilizer rates are determined based on soil test results and the cropping system (BAU-1, BAU-2, ASP-1, and ASP-2). All plots are continuously monitored for soil water content and soil water potential with sensors that are removed before planting then re-installed after planting. Logging equipment (one for paired plots), with modem and solar charged batteries, is used to collect and transmit data to a base station. We have had difficulty establishing a good stand of carinata using strip tillage in small plots, weed competition has been intense, and late winter frosts have resulted in considerable crop damage. We will attempt minimum tillage in small plots in the fall to improve soil-seed contact and add larger plot trials to evaluate potential management strategies to reduce late frost damage risk.
Objective 1.2. The collaborating researcher responsible for this objective retired in late December 2020. The data on the bees collected from the 2020 peanuts were sent off for identification. The plots were mowed in 2020. A replacement researcher (Entomologist) was recruited in 2021. Native wildflowers were planted on the borders of the irrigated and dryland plots in April 2022. The flowers at the dryland plots did not survive this year’s heat and drought and will be replanted this fall. Bees are being collected on blue vane traps placed in the wildflower areas.
Objective 2.1. ARS researchers in Tifton, Georgia, continued research activities at micro-plots at Gibbs Farm under Phase III (cease poultry litter amendments; 2020, 2021, and 2022). The research assesses the impacts of application of flue gas desulfurization gypsum and poultry litter on corn production, soil properties, and nutrients in runoff. Thirty of the plots with and without grass buffers are equipped for runoff water quality sampling. In Phase III, fertilization is all inorganic (NPK) with no gypsum application except for 3 plots in each replication that during Phase II were under NPK fertilization with 2 tons per acre per year of gypsum application. The phasing allows monitoring of the residual effects of poultry litter and gypsum applications as rates were reduced or eliminated. A winter rye cover was grown in 2022 and biomass determined. In early spring 2022, soil samples were collected and analyzed for determining fertility status and fertilizer recommendations. The rye was rolled and chemically killed before incorporating into the soil by disking and planting of the 2022 summer corn crop which is expected to be harvested in September 2022. Processing started of the 3-year interval 3-ft deep soil cores collected in spring 2020. The final set of soil cores will be collected in the spring of 2023 and event-based runoff sample collection from the 30 plots will continue until this time. A manuscript by ARS scientists at Tifton, Georgia on treatment effects on water quality during Phase I (2014- Jan. 2017) has been published in the Journal of Soil and Water Conservation. Data on treatment effect on corn grain yield during Phase I & II have been compiled.
Objective 2.2. The collaborator has indicated that he will no longer be able to continue working with us vis-à-vis Objective 2.2 as his assignment has moved to a new project that does not fit any of the objectives of this NP216 project. Future efforts on antimicrobial resistance elements and food-borne pathogens have been discontinued, but submission of a draft manuscript, Management and environmental factors influence the prevalence and abundance of food-borne pathogens and commensal bacteria in peanut hull-based broiler litter, is expected in FY22. A postdoc was onboarded in 2021 to begin working on the soil microbial community profiling.
Objective 3. ARS researchers in Tifton, Georgia, continued to acquire continuous weather data from the fully operational weather station installed at Wilson Farm (Cooperator). Before passing away in 2022, the cooperator was accessing the data on his mobile phone and checking on rainfall amount to initiate or limit irrigation and used our soil temperature data to initiate planting, often two weeks ahead of neighboring farmers. ARS researchers in Tifton, Georgia, continued raising Mott Napier grass in green houses and replanting in marginal production areas of the farm; this grass has proven popular with cattle and producer alike and will be expanded. A cooperative agreement was signed with the cooperator that allocates a six-acre field for scaled up research on one rotation from Objective 1.1. The first cover crops of rye and carinata were planted and harvested followed by planting of cotton and peanuts on 3-ac each. These activities demonstrated that carinata could be grown and perform well in large fields. Bi-weekly water sampling (grab samples) for water quality analyses was initiated in April 2020 at the inlet and outlet of the farm. Water quality analyses including measurements of dissolved nitrate+nitrite, dissolved ammonia, dissolved orthophosphate, and dissolved chloride have been completed up to fall 2021. The cooperator’s site has also been included in an ARS Beltsville NP108 project, Development and Validation of Farm-Scale Microbial Quality Model for Irrigation Water Sources.
Accomplishments
1. Byproducts from poultry production and coal-fired power generation have beneficial uses in agricultural production systems of the U.S. Coastal Plain. ARS researchers in Tifton, Georgia, demonstrated that flue gas desulfurization gypsum (FGDG) and grass buffer strips (GBS) reduce edge-of-field nutrient losses from corn production under organic (broiler litter) fertilization. When fertilizing corn with broiler litter, the combined use of FGDG and GBS was found to reduce nitrogen (N) and phosphorus (P) loads by 35 to 60%. These results indicate the potential for FGDG and GBS to improve edge-of-field runoff water quality in cropping systems of the southeast, where broiler litter is commonly used as a fertilizer source.
2. Winter cover crops can improve summer crop yields even when harvested. Legumes planted as winter covers on Southern fields can improve soil health and enhance the following summer crops by capturing nitrogen from the air. Winter covers are often tilled under or left in the field and rolled, but they could be harvested for forage. ARS researchers in Tifton, Georgia, conducted a 5-year study to compare biomass yields of five different legumes or rye, along with fallow checks. The covers were either harvested or rolled and were followed with high-biomass sorghum or cotton. Narrow-leaf lupin was the highest-yielding winter cover. Lupin, vetch, and winter pea covers had positive effects on summer biomass sorghum yields. Cotton lint yields were highest after lupin and vetch. Harvesting the covers reduced sorghum yields following some covers but not following lupin or vetch. Cotton yields were not affected by harvesting versus rolling of any winter covers. The study suggests that growers could harvest lupin and vetch for animal feed or other uses and still improve summer row crop yields, thus increasing overall farm income and improving soil health.
3. Brassica carinata, commonly known as carinata or Ethiopian mustard, is gaining interest as an oilseed biofuel crop suitable for winter production in the southeastern U.S. Other Brassica species are known to be excellent hosts for whiteflies which spread viral diseases to crops. ARS researchers in Charleston, South Carolina and Tifton, Georgia, demonstrated that whitefly egg laying, hatching, and survival to adulthood on carinata was equal to collard, which is known to support high whitefly populations. Whiteflies survive the mild winters in the southeastern United States and although populations are typically suppressed during winter, the potential exists that the presence of preferred host plants during mild winters may support a buildup of whiteflies during the spring. While whitefly-transmitted viruses have yet to be reported in carinata, it would add to the numerous plants that can support whitefly populations during mild winters and may have implications for whitefly ecology and management.
Review Publications
Endale, D.M., Strickland, T.C., Schomberg, H.H., Bosch, D.D., Pisani, O., Coffin, A.W. 2021. Flue gas desulfurization gypsum and grass buffer strips influence on runoff and nutrient loss from inorganically and organically fertilzed corn on a US Coastal Plain soil. Journal of Soil and Water Conservation. https://doi.org/10.2489/jswc.2021.02156.
Timper, P., Strickland, T.C., Jagdale, G.B. 2021. Biological suppression of the root-knot nematode Meloidogyne incognita following winter cover crops in conservation tillage cotton. Biological Control. 155:104525. https://doi.org/10.1016/j.biocontrol.2020.104525.
Olaniyi, O.G., Andreason, S.A., Strickland, T.C., Simmons, A.M. 2021. Brassica carinata: new reproductive host plant of Bemisia tabaci (Hemiptera: Aleyrodidae). Entomological News. 129(5):500-511. https://doi.org/10.3157/021.129.0504.
Bryant, R.B., Endale, D.M., Spiegal, S.A., Flynn, K.C., Meinen, R.J., Cavigelli, M.A., Kleinman, P.J. 2021. Poultry manureshed management: Opportunities and challenges for a vertically integrated industry. Journal of Environmental Quality. 1-12. https://doi.org/10.1002/jeq2.20273.
Anderson, W.F., Knoll, J.E., Olson, D.M., Scully, B.T., Strickland, T.C., Webster, T.M. 2022. Winter legume cover effects on yields of biomass-sorghum and cotton in Georgia. Agronomy Journal. 114(2):1298-1310. https://doi.org/10.1002/agj2.21018.
