Diurnal Pattern of Soil Moisture and Temperature Under Corn and Soybean Fields in South Dakota.

Agricultural drought is an expeditious manifestation of a meteorological drought. Under conditions of limited rainfall input coupled with high temperature values, soil moisture depletes, which led to partial or total crop failure in agroecosystems. The soil moisture and temperature relationship is of special interest to plant growth, and can be used as an indicator of the impact of drought on crop production. In this study, the diurnal pattern of soil moisture and temperature under corn and soybean fields managed with conservation tillage systems was investigated from 5 producers farms located in eastern South Dakota, USA. Measurement of soil moisture and temperature were conducted at 0-15, 15-30, and 30-45 cm soil depths in 2015 and 2016. In addition, soil properties, namely bulk density, soil organic carbon, total nitrogen, pH, and electrical conductivity were measured at each soil depth. Data collection also included precipitation and air temperature records from each individual farm. Preliminary results showed significant soil moisture and temperature changes with season and cropping growth stage. This study suggests that the diurnal patterns of soil moisture and temperature can be useful in detecting the drought conditions.