Cover crop influence on soil water dynamics for a corn–soybean rotation

Abstract

Crop production is reduced by insufficient and/or excess soil water, which can significantly decrease plant growth and development. Therefore, conservation management practices such as cover crops (CCs) are used to optimize soil water dynamics, since CCs can conserve soil water. The objective of this study was to determine the effects of CCs on soil water dynamics on a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation at three soil depths over 3 yr. The study was conducted at the Chariton County Cover Crop Soil Health Research and Demonstration Farm (CCSH) in Missouri. Initial CC establishment occurred in 2012. Volumetric soil water content (VWC) was monitored at 15-min intervals with calibrated Waterscout SM100 soil moisture sensors (Spectrum Technologies) at three depths (10, 20, and 30 cm) in 2016, 2017, and 2018. Cover crop soils maintained numerically higher VWC values compared with no CC (NCC) at both 10- and 20-cm depths throughout the study period where the differences were significant in some weeks. The subsurface soil water recharge was greater in CC soils at both 10- and 20-cm depths compared with NCC in March 2017. The results imply that CC soils have maintained higher VWC levels during vegetative period of the CC growth where the differences were significant in some weeks compared with NCC at all three soil depths. These findings can be used to promote CC adoption for better soil water storage and develop CC management plans for corn–soybean rotations on claypan soils.