Location: Soil Dynamics ResearchTitle: Evaluation of cover crop mixtures for improving soil health in ultisols
|JOHNSON, ANNA - Auburn University
|GAMBLE, AUDREY - Auburn University
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/3/2019
Publication Date: 11/11/2019
Citation: Johnson, A., Balkcom, K.S., Gamble, A.V. 2019. Evaluation of cover crop mixtures for improving soil health in ultisols[absstract]. ASA-CSSA-SSSA Annual Meeting. CD ROM.
Technical Abstract: The restoration of soil health is a crucial step in maximizing productivity in the historically-eroded Ultisols of the Southeast. The utilization of winter cover crops in southeastern row-crop production systems can potentially improve soil health by increasing soil organic matter, improving soil structure, and enhancing nutrient-use efficiency. Studies were established in southeast and north Alabama to examine the impact of cover crop monocultures and mixtures on dynamic soil health indicators in cotton production systems. Eight treatments including monocultures and combinations of cereal rye (Secale cereal), crimson clover (Trifolium incarnatum), and Daikon radish (Raphanus sativus) were arranged in a randomized complete block design with winter fallow controls. Cover crop biomass was collected at termination, and soil samples were collected two weeks following termination. Soil health indicators measured include permanganate-oxidizable carbon (POXC), water stable aggregates (WSA), and soil compaction. In both 2018 and 2019, POXC in north Alabama was not different between treatments at the 0-5 cm and 5-10 cm depths, while POXC was higher under crimson clover compared to the rye/crimson clover mixture at 10-15 cm. There were no differences in POXC between treatments in southeast Alabama, but POXC was higher in 2019 than in 2018. WSA values from both locations were not different between treatments within the same depth class in both 2018 and 2019. At both locations, soil was less compacted in 2019 than in 2018. No differences between treatments were observed in North Alabama, while the rye monoculture was less compacted than the crimson clover monoculture and crimson clover/radish mixture at the southeast Alabama location. Continuation under these treatments may be required to detect changes in soil health.