Research Project: Conservation Systems to Improve Production Efficiency, Reduce Risk, and Promote Sustainability

Location: Soil Dynamics Research

2023 Annual Report

Objectives
1. Determine weed suppression, soil coverage, and agronomic and economic benefits for monoculture and mixed species high-residue cover crops in conservation tillage for diverse crop production systems of the southeastern U.S. 1a. Evaluate monoculture and mixtures of cereal, legume, and selected Brassica cover crop species on weed dynamics in corn, cotton, peanut, and soybean. 1b. Evaluate and develop integrated weed control systems to diminish herbicide resistant and troublesome weed yield loss in cotton. 1c. Evaluate cover crop management across single species and mixtures to compare soil health benefits, while improving biomass production. 2. Integrate new equipment, high residue cover crops, and conservation tillage into cropping systems that foster sustainability and resiliency, increase efficiency, and reduce risk by promoting soil health and yield stability. 2a. Evaluate effects of different planting factors in a no tillage cotton system with a rye cover crop. 2b. Develop a no tillage equipment system compatible with a modular tractor for vegetable production. 2c. Determine the effects of cereal rye seeding rates and timing of termination methods on soybean production in a no tillage conservation system. 2d. Determine cash crop performance across high residue conservation tillage systems and different agronomic management factors. 3. Increase environmental sustainability of pasture and forage-based beef production systems. Research can include, but is not limited to, incorporating broiler litter into pasture-based grazing systems; cropping systems with beef cattle production through grazing cover crops utilized in soil conservation programs; production of forages adapted to local growing conditions and resilient to a changing southern climate to improve production efficiency and environmental benefits; and lowering fertilizer and energy inputs and associated production costs to maximize profitability.

Approach
Research objectives are designed to develop conservation systems that will improve soil quality, conserve natural resources, and increase production efficiency, increase environmental sustainability of pasture and forage-based beef production systems, while reducing risk for producers. These objectives will be accomplished by examining cover crop benefits (agronomic and economic) for single species and mixtures across diverse cropping systems of the southeast. In addition, we will also examine how integrating cover crops with management strategies designed to maximize benefits for cropping systems will promote soil health and productivity. Major areas of focus include: (1) examining weed germination across single species cover crops and mixtures for popular row crops grown across the southeast; (2) integration of cover crop mixtures into herbicide resistant weed control strategies; (3) comparisons of cover crop management strategies across single species cover crops and mixtures to identify how to maximize benefits; (4) evaluation of cover crop seeding rates, termination timing, and cash crop planting speeds on cash crop productivity; (5) development of equipment for a modular tractor suitable for vegetable production; (6) evaluation of cash crop performance across high residue cover crop systems; and (7) identifying tillage and seeding rate guidelines for a carinata biofuel crop. In addition, the research will focus on incorporating broiler litter into pasture-based grazing systems; cropping systems with beef cattle production through grazing cover crops utilized in soil conservation programs; production of forages adapted to local growing conditions and resilient to a changing southern climate to improve production efficiency and environmental benefits; and lowering fertilizer and energy inputs and associated production costs to maximize profitability.

Progress Report
This is the final report for this project. New project currently going through research review. Experiments, data analysis, and manuscript synthesis have been accomplished for numerous experiments designed to examine how cover crop management affects cover crop benefits and challenges. Experiments, data analysis and manuscript synthesis are also concluding that include comparisons between single cover crop species and multi-species cover crop mixtures for soil C levels, microbial activity, and weed suppression across various cropping systems. Research was concluded for carinata, a potential biofuel crop for the Southeast, that involved investigating interactions between carinata seeding rates and conventional and conservation tillage systems. Studies were also concluded for tillage comparisons among different forms of surface tillage across different N rates for winter wheat production. Cooperative research with Auburn University to examine how single and multi-species cover crops affect soil properties is also continuing in final stages, as well as determining how cover crop grazing duration affects soil and crop productivity. In addition, experiments evaluating cover crop termination and transplanting machinery design and subsequent design refinement continue in final stages. New research efforts were established at the NSDL for sustainable production of forage using plant growth-promoting rhizobacteria (PGPR). Evaluation of PGPR as an alternative or supplement to fertilizer for tall fescue and bermudagrass under field conditions were conducted in Alabama and Tennessee. Technology transfer activities have continued, which are related to many facets of all the previously described research. As this project is coming to an end, we summarize this research in this paragraph. Due to this research, Extension recommendations throughout the southeast for integrated weed management are revised to reflect weed suppressive attributes that high-residue cover crops provide when establishing weed management strategies in conservation tillage cotton. Alternative control strategies that include cover crops and residual herbicides are being widely promoted by NRCS and cooperative extension systems across the Southeast to help control resistant weeds without the need for intensive tillage, which is a detriment to soil quality. Due to specialty crop research, Extension, USDA-NRCS and growers increasingly recommend and adopt integrated weed management recommendations that control weeds, decrease economic risk, and protect the environment. Much of the research related to cover crops served as the basis for numerous speaking invitations to educate growers and technical service providers on successful cover crop management. For example, the American Society of Agronomy selected two separate projects to construct self-study exams sent to 14,000 certified crop advisors to educate them about these conservation tillage practices and fertilizer interactions. Other examples include a national NRCS webinar, as part of training for employees, and an on-demand webinar available through the Plant Management Network website https://www.plantmanagementnetwork.org/edcenter/seminars/cotton/CoverCropManagement/, under the Focus on Cotton tab to educate viewers about how cover crop management decisions affect soil health and benefits for subsequent crops in the Southeast. The wheat/tillage research was also highlighted in a congressional report designed to illustrate significant NP 216 research results. In addition, development of rollers/crimpers for cover crop management, planting and transplanting equipment allowed for increasing cover crops use on limited resources small farming operations. There have been many inquiries from producers regarding availability of this equipment on the market. A tractor company in Alabama continues interest in cooperation with the inventor to develop a commercial specialized equipment. The accomplishments above result from research generating approximately 35 peer reviewed journal publications over the project’s five-year lifespan.

Accomplishments
1. Viability of carinata in the southeastern United States shown through evaluation of agronomic practices. A major limitation to carinata adoption as a winter crop in the region was a lack of information on double-cropping with popular summer commodity crops (i.e., peanut and cotton). Agronomic management practices to optimize yield and ensure winter carinata production compatibility with existing cropping systems are crucial for successful development of a carinata supply chain in the southeastern United States. Different studies were conducted by Univ. of Florida researchers and an ARS researcher in Auburn, Alabama, to evaluate carinata performance across land preparation methods and seeding rates, double-crop performance following popular summer crops, and carinata effects on subsequent summer crops. Results from these studies showed carinata was not affected by previous summer crops, but double-cropping carinata caused a delay in timely planting of cotton and peanut. A planting delay is a limitation that may hinder adoption of carinata double-cropping systems in the region until an early maturing carinata cultivar can be developed. However, these series of studies proved winter carinata’s viability as a replacement for winter fallow across the region to boost grower revenue and increase land use efficiency.

2. Soil health changes vary across soil types. The southeastern United States has degraded soils caused by intensive conventional agriculture and detrimental climatic factors (e.g., extreme heat and rainfall) that can benefit from management practices that promote soil health. ARS researchers at Auburn University and an ARS researcher in Auburn, Alabama, studied cover crop performance and short-term effects on soil health indicators for a north (silt loam) and south Alabama (loamy sand) soil across winter fallow, monocultures, and two- and three-way mixtures of rye, crimson clover, and forage radish. All cover crops, except the radish monoculture, increased soil organic carbon 19-30% in the surface at north Alabama compared to winter fallow after five years, but this effect was not observed in south Alabama. Cover crop mixtures were no better than monocultures at improving soil health indicators compared to fallow. Results showed cover crops can increase soil organic carbon across degraded soils and under the region’s extreme climate, but these effects were dependent on soil type and cover crop.

3. A clover cover crop delays weed competition in corn. An increasing number of herbicide-resistant weeds, in addition to troublesome weeds, pose a significant challenge for chemical weed control in corn. Simultaneously, high-biomass cover crop adoption has gained popularity among farmers as an efficient weed control strategy. ARS researchers in Auburn, Alabama, conducted a two-year field experiment to estimate the influence of a high biomass crimson clover cover crop and conservation tillage on the critical timing of weed control (CTWR) and the critical weed free period (CWFP) in corn. These factors determine when weed control needs to be initiated within the crop and the end of when control is needed to maintain yield. The presence of a crimson clover cover crop delayed the CTWR and caused the early beginning of CWFP and hence shortened the time weed control needed to be maintained in 2019. During most of the growing season, weed biomass production was less following conservation plus clover compared to conventional tillage plots or conservation tillage with winter fallow stems in both years.

4. Development of a no-till transplanter for walk-behind tractors utilized in limited resource farming. A no-till vegetable transplanter powered by a walk-behind tractor was developed by ARS researchers in Auburn, Alabama, to reduce difficult physical labor that is required in limited resource small scale farming operations. Currently, there are no existing commercially available no-till transplanters made for walk-behind tractors. The original patented concept was heavy (103 kg) and included complex mechanical assemblies to be powered by the tractor’s PTO (power-take-off). The improved version of the transplanter has fewer components and weighs only 83 kg, a decrease of 20 kg (19% weight reduction). This new version of a modular design allows easier and faster transplanter fabrication, giving farmers an option to fabricate their own transplanter to reduce costs and increase adoption of no-till vegetable systems with cover crops. Based on the results, the modified electric transplanter provided more uniform spacing of transplanted tomato seedlings compared with the original mechanically driven transplanter and is a viable solution for small scale farm operators who already own 2-wheel walk-behind tractors as their power source and can provide a way to further adopt conservation agriculture practices in limited resource small-scale farming systems.

5. Plant growth regulator applications for conservation tillage cotton. Conservation tillage and cover crops, which may enhance soil moisture conservation, could delay cotton maturity that can negatively affect harvest. In these systems, cotton nitrogen rates may be increased to offset potential immobilization of applied nitrogen associated with surface residues, but more nitrogen may promote excessive growth that also delays maturity and/or reduces yield. Plant growth regulator (PGR) applications applied during the season are one strategy to limit excessive vegetative growth and alter maturity to promote timely harvest, but over-application can also decrease yield. Therefore, an ARS researcher in Auburn, Alabama, in conjunction with researchers from North Carolina State University and Auburn University, compared how different PGR strategies affected cotton plant growth and yield across two nitrogen rates in a conservation tillage system. Yield response to different PGR strategies varied across the five site-years and ranged from a 16% yield decrease to a 9% yield increase, but growing conditions for excessive growth that would call for aggressive PGR strategies were not observed. Although PGR response was variable in these systems, cotton growers using conservation systems can expect PGR performance comparable to observed PGR performance across different cotton systems.

6. Source of plant available nitrogen does not affect nutrient accumulation in corn ears. Mineral composition of corn ears affects their nutritional value and potential use as human food and animal feed. Broiler litter (BL), a readily available source of mineral elements in the southeastern U.S., could be an economical source for corn ear nutrition, but broiler litter’s ability to supply mineral elements compared to conventional fertilizers is unknown. Auburn University collaborators and ARS researchers in Auburn, Alabama, conducted a 2-yr study to investigate the mineral composition of corn ears as affected by nutrient source (BL or urea), application rate (0, 168, and 336 kg total N ha-1), and application time (single or split) at three locations in Alabama, USA. Broiler litter, regardless of application rate and application time, did not increase any elemental concentrations in the corn ear. However, corn fertilized with urea had the greatest corn ear concentrations of N, P, K, Ca, Mg, Zn, Mn, Fe, and Cu across all locations. Corn growers should recognize that an optimal supply of plant available nitrogen in the soil, regardless of nutrient source, produced corn ears with the highest N and other mineral concentrations.

7. Grazing of cool-season cover crops has been shown to be a viable tool in extending the grazing season while mitigating environmental risks associated with row crop farming systems. Results indicate that grazing of cool-season annual cover crops will reduce forage yield, but removal date of cattle will not further affect forage yield, quality, or individual cattle performance. Thus, ARS researchers in Auburn, Alabama, can reduce winter supplementation needs for cattle by increasing grazing days; however, under continuous grazing for stocker cattle production, forage availability may inevitably be the limiting factor.

Review Publications
Kornecki, T.S., Kichler, C.M. 2022. Development of a no-till transplanter for walk-behind tractors. Journal of the ASABE. 38(6):865-872. https://doi.org/10.13031/aea.15126.
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.
Kumar, V., Kumari, A., Price, A.J., Bana, R.S., Singh, V., Bamboriya, S.D. 2023. Impact of futuristic climate variables on weed biology and herbicidal efficacy: a review. Agronomy. 13(2):559. https://doi.org/10.3390/agronomy13020559.
Kumari, A., Price, A.J., Koores, N., Gamble, A., Li, S. 2023. Effect of crimson clover on the critical period of weed control in conservation tillage corn. Frontiers in Agronomy. 4:1068365. https://doi.org/10.3389/fagro.2022.1068365.
Iboyi, J.E., Mulvaney, M.J., Leon, R.G., Balkcom, K.S., Bashyal, M., Perondi, D., De S Noja Junior, R., Devkota, P., Small, I.M. 2023. Brassica carinata physiological response to land preparation method and seeding rate. Journal of Crop Improvement. 38(1):25-39. https://doi.org/10.1080/15427528.2022.2163950.
Iboyi, J., Mulvaney, M., Leon, R., Balkcom, K.S., Bashyal, M., Devkota, P., Small, I. 2023. Double-cropping effects of Brassica carinata and summer crops: I. Effects of summer cropping history on carinata production. Industrial Crops and Products. 194:116364. https://doi.org/10.1016/j.indcrop.2023.116364.
Iboyi, J., Mulvaney, M., Leon, R., Devkota, P., Bashyal, M., Balkcom, K.S., Small, I. 2023. Double-cropping effects of Brassica carinata and summer crops: II. Effects of winter cropping history on subsequent summer crop production. Industrial Crops and Products. 197:116609. https://doi.org/10.1016/j.indcrop.2023.116609.
Ul Khabir, I., Topps, D., Jhumur, J., Adesemoye, A.O., Brown, J., Newman, A., Robertson, B., Iqbal, J., Saleem, M. 2023. Linking rhizosphere soil aggregates with belowground and aboveground plant traits. Ecologies. 4(1):74-87. https://doi.org/10.3390/ecologies4010007.
Balkcom, K.S., Monks, C., Brown, S.M. 2022. Mepiquat chloride applications across two nitrogen rates in a conservation tillage cotton system. Journal of Cotton Science. 26:1-13.
Decker, H., Gamble, A.V., Balkcom, K.S., Johnson, A., Hull, N. 2022. Cover crop monocultures and mixtures impact soil health indicators in the southeast United States. Soil Science Society of America Journal. 86:1312-1326. https://doi.org/10.1002/saj2.20454.
Banerjee, P., Rodning, S.P., Diniz, W.J., Dyce, P.W. 2022. Co-expression network and integrative analysis of metabolome and transcriptome uncovers biological pathways for fertility in beef heifers. Metabolites. 12:708. https://doi.org/10.3390/metabo12080708.
Banerjee, P., Diniz, W.J., Hollingsworth, R., Rodning, S.P., Dyce, P.W. 2023. mRNA Signatures in peripheral white blood cells predict reproductive potential in beef heifers at weaning. Genes. 14:498. https://doi.org/10.3390/genes14020498.
Diniz, W.J., Banerjee, P., Rodning, S.P., Dyce, P.W. 2022. Machine learning-based co-expression network analysis unravels potential fertility-related genes in beef cows. Animals. 12:2715. https://doi.org/10.3390/ani12192715.
Diniz, W.J., Ward, A.K., Mccarthy, K.L., Kassetas, C.J., Baumgaertner, F., Reynolds, L.P., Borowicz, P.P., Sedivic, K.K., Kirsch, J.D., Dorsam, S.T., Neville, T.L., Forcherio, J.C., Scott, R., Caton, J.S., Dahlen, C.R. 2023. Periconceptual maternal nutrition affects fetal liver programming of energy- and lipid-related genes. Animals. 13(4):600. https://doi.org/10.3390/ani13040600.
Diniz, W.J., Ward, A.K., Mccarthy, K.L., Kassetas, C.J., Baumgaertner, F., Reynolds, L.P., Borowicz, P.P., Sedivic, K.K., Kirsch, J.D., Dorsam, S.T., Neville, T.L., Forcherio, J.C., Scott, R., Caton, J.S., Dahlen, C.R. 2023. Dataset of RNA-Seq transcriptome of the fetal liver at day 83 of gestation associated with periconceptual maternal nutrition in beef heifers. Data in Brief. 48:109173. https://doi.org/10.1016/j.dib.2023.109173.
Banerjee, P., Diniz, W.J., Rodning, S.P., Dyce, P.W. 2023. miRNA expression profile of peripheral white blood cells from beef heifers with varying reproductive potential. Frontiers in Genetics. 14:1174145. https://doi.org/10.3389/fgene.2023.1174145.
Anas, M., Diniz, W.J., Menezes, A.C., Reynolds, L.P., Caton, J.S., Dahlen, C.R., Ward, A.K. 2023. Maternal mineral nutrition regulates fetal genomic programming in cattle: a review. Metabolites. 13(5):593. https://doi.org/10.3390/metabo13050593.
Banerjee, P., Diniz, W.J., Rodning, S.P., Dyce, P.W. 2023. Transcriptomic dataset from peripheral white blood cells of beef heifers at weaning. Data in Brief. 48:109046. https://doi.org/10.1016/j.dib.2023.109046.
Wagoner, M.P., Reyes, T.M., Zorn, V.E., Coursen, M.M., Corbitt, K.E., Wilborn, B.S., Brandebourg, T.D., Belk, A.D., Bonner, T., Sawyer, J.T. 2022. Influence of vacuum packaging on instrumental surface color characteristics of frozen beef steaks. Journal of Food Science and Nutrition. 5(3):658-663. https://doi.org/10.26502/jfsnr.2642-110000111.
Wagoner, M.P., Reyes, T.M., Zorn, V.E., Coursen, M.M., Corbitt, K.E., Wilborn, B.S., Starkey, C.W., Brandebourg, T.D., Belk, A.D., Bonner, T., Sawyer, J.T. 2022. Vacuum packaging maintains fresh characteristics of previously frozen beef steaks during simulated retail display. Foods. 11(19):3012. https://doi.org/10.3390/foods11193012.
Mullenix, M.K., Stewart, R.L., Jacobs, J.L., Davis, D.L. 2022. Invited review: Using whole cottonseed and cotton harvest residue in southeastern US beef cattle diets: Quality, intake, and changes in feed characteristics. Applied Animal Science. 38(5):447-455. https://doi.org/10.15232/aas.2022-02301.
Pandey, S., Bag, S., Roberts, P., Conner, K., Balkcom, K.S., Price, A.J., Jacobson, A.L., Srinivasan, R. 2022. Prospective alternate hosts of an emerging polerovirus in cotton landscapes in the southeastern United States. Viruses. 14(10):2249. https://doi.org/10.3390/v14102249.
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.
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.