Cover Crop Influence on Soil Water Dynamics Under Corn-Soy Bean Rotation.

Soil moisture plays an important role in plant growth. Cover crops (CC) are being promoted for soil conservation and soil improvement by increasing soil organic matter, moisture and fertility and reducing soil erosion. CC growth during fallow period can also affect soil water dynamics by using plant available water and reducing soil evaporation. This study was conducted at the Chariton County, Cover Crop Soil Health (CCSH) Research and Demonstration Farm, Missouri with the objective of quantifying the effects of CC on soil water dynamics under corn-soybean rotation system. Four plots were used for the study; two with CC and two without, as the control. Initial CC establishment was done in 2012. Volumetric soil moisture (SM) content was estimated at 15 minute intervals by Waterscout SM100 SM sensors (Spectrum Technologies) in three depths (20, 30 and 40cm) at 6 locations per plot, as three replicates in each summit and food slope positions. Analysis of variance (ANOVA) and least significant difference (LSD) mean separation procedures of data showed significantly (p<0.05) higher soil moisture availability at 20cm and 30cm depth at foot slope position in the plots managed with CC compared to the control. The difference between the treatments were not significant during the winter months of 2016. Results of the study will help determine the effects of CC growth on soil water dynamics under corn-soybean rotation in mid Missouri and to develop a comprehensive CC management plan.

Key words: Cover crops, Soil moisture dynamics, Soil health