Location: Soil Dynamics Research
2022 Annual Report
Accomplishments
1. Cover crop grazing in southeastern U.S. cropping systems. Grazing livestock on winter forages in the Southeast U.S. raises questions about the possibility of these forages also serving as cover crops. Extended grazing periods may benefit livestock but diminish surface residue and subsequent soil health benefits. Auburn University collaborators and ARS researchers at Auburn, Alabama, examined winter grazing impacts on soil health indicators for three cattle removal dates and an non-grazed control in a cotton/peanut rotation. Increasing soil organic content (SOC) and improving soil health with winter grazing of cover crops exists for producers with row crop and livestock operations. After two years, microbial biomass carbon (C) was highest in the control treatments, likely due to greater cover crop biomass on the soil surface at termination. No differences were observed between treatments for other soil health indicators that suggests integrating winter grazing livestock does not negatively nor positively impact selected dynamic soil properties in the short-term. More time under grazing treatments is needed to thoroughly evaluate how winter grazing livestock impact soil health.
2. Soil health changes minimal from short-term cover crop use. Soil health restoration is crucial to maximize productivity in historically eroded soils of the southeastern United States. Cover crops are one management strategy to improve soil health and future productivity. Auburn University collaborators and ARS researchers at Auburn, Alabama, examined various soil health indicators following 2 years of cover cropping before cotton in fine-textured soils of north and coarse-textured soils of south Alabama. Monocultures, which may cost less, produced equal biomass to potentially more expensive mixtures. However, soil health indicators seldom differed between monocultures and mixtures after 2 years of cover crop treatments, although soil carbon (C) increased on the fine-textured soil. Our results demonstrate that long-term cover crop use may be required to produce documentable, consistent changes in soil health properties.
3. Sunn-hemp cover crop management in a no-till corn system in Cambodia. Conservation agriculture (CA) is gaining popularity in Cambodia to sustain soil fertility, productivity, and profits. However, the adoption remains low due to the insufficient engagement of local equipment services into CA machinery and knowledge. Kansas State University and Cambodia Royal University of Agriculture collaborators and ARS researchers at Auburn, Alabama, compared different no-till seeders and sunn hemp residue retention methods for corn sowing and to determine their effects on growth and yield. The results show plant population, plant diameter, and kernel characteristics were greater with the ‘Brazilian’ seeder, when compared to the ‘Morrison’ seeder. Soil moisture was also significantly affected by residue retention with higher volumetric moisture content following rolled and crimped residue compared to disked/incorporated residue. Our study demonstrates that using rollers/crimpers and no-till planters is feasible in Cambodia’s small farming CA systems although more research is needed to study long-term effects on crop yield and soil health.
4. Cover crop termination methods on no-till cantaloupe. In a no-till system, there are many methods to terminate cover crops including mechanical termination by rolling and crimping or mowing, but mowing can result in cover crop re-growth and loose residue interfering with the planter during subsequent cash crop planting. ARS researchers at Auburn, Alabama, conducted research to determine the effects of different cover crops and termination methods on cantaloupe yield in a no-till system. Crimson clover, cereal rye, and hairy vetch cover crops were terminated using two different roller-crimpers, including a two-stage roller-crimper attached to a traditional four-wheel tractor and a powered roller-crimper attached to a two-wheel walk-behind tractor, and evaluated weekly for three weeks after rolling. Three weeks after rolling, higher termination rate was found for flail mowing compared to lower termination rates for a two-stage roller and powered roller-crimper. There were no significant differences in cantaloupe yield among the rolling treatments; however, yields were higher for cereal rye and hairy vetch cover crops compared to crimson clover.
Review Publications
Kornecki, T.S., Kichler, C.M. 2022. Effectiveness of cover crop termination methods on no-till cantaloupe. Agriculture. 12(1):66. https://doi.org/10.3390/agriculture12010066.
Singh, R., Prasad, R., Guertal, E., Balkcom, K.S., Lamba, J. 2021. Effects of broiler litter application rate and time on corn yield and environmental nitrogen loss. Agronomy Journal. 114:415-426. https://doi.org/10.1002/agj2.20944.
Crowell, H., Gamble, A., Feng, Y., Balkcom, K.S., Yang, A. 2021. Impacts of winter grazing on soil health in southeastern cropping systems. Agrosystems, Geosciences & Environment. 5:e20240. https://doi.org/10.1002/agg2.20240.
Johnson, A.M., Gamble, A., Balkcom, K.S., Hull, N.R. 2021. Influence of cover crop mixtures on soil health in southeastern crop production. Agrosystems, Geosciences & Environment. 4:e20202. https://doi.org/10.1002/agg2.20202.
Korres, N.E., Loka, D.A., Gitsopoulos, T.K., Varanasi, V.K., Chachalis, D., Price, A.J., Slaton, N.A. 2022. Salinity effects on rice, rice weeds, and strategies to secure crop productivity and effective weed control. A review. Agronomy for Sustainable Development. 42:58. https://doi.org/10.1007/s13593-022-00794-4.
Greene, W., Tredaway, J., Price, A.J., Monks, D. 2022. Cotton (gossypium hirsutum) cultivar response to glufosinate plus s-metolachlor applied post using two nozzle types. Weed Technology. 35:1023-1028. https://doi.org/10.1017/wet.2021.102.
Hin, L., Kornecki, T.S., Reyes, M., Tivet, F., Hok, L., Buntong, B., Lor, L., Leng, V., Suos, V., Clemmons, H. 2021. Effects of different management methods for sunn-hemp cover crop on corn production in a no-till system in Cambodia. Applied Engineering in Agriculture. 37(5):805-818. https://doi.org/10.13031/aea.14345.