Early impacts of cover crop selection on soil biological parameters during a transition to organic agriculture

Although Texas is not widely known for organic production, it is responsible for most organic peanut production in the United States. When managed effectively, this can be a lucrative practice due to consumer demands. However, farmers pursuing organic management must undergo a 3-year transition period to obtain United States Department of Agriculture certification, which is often associated with depressed yields. The objective of this study was to measure the impact of organic management and cover crop selection on biological indicators of soil health during the second year of transitioning to an organic cotton–peanut rotation in West Texas. We conducted a field study at two locations, and soil health indicators including in situ respiration, carbon mineralization, enzyme activities, and phospholipid fatty acids (PLFAs) were measured. The use of a cover crop resulted in generally greater biological activities compared to the fallow after only one cover crop rotation, representing early elevated biological activities under plots treated with a cover crop. However, cover crop species selection typically does not affect soil biological parameters. Cover crop use also did not contribute to yield losses when compared to a fallow treatment. When comparing organic management to conventional management, both sites experienced elevated PLFA counts under organic management. Importantly, results indicated that although reduced peanut yields could be expected under transitional organic management, this was not cover crop species-specific, nor was it a guarantee. Given the economic risk of organic management for farmers, this study will benefit producers deciding whether to pursue organic production and cover cropping.