This study investigated the relationships between corn (Zea mays L.) grain yield and weather over a range of soil rooting depths with and without irrigation. The purpose was to test if variability of corn grain yield over a range of soil rooting depths could be reduced if water is supplied via irrigation. An additional goal was to test a simple water balance simulation model which calculates a seasonal moisture stress index based on relative evapotranspiration deficits. Such a water budget model could be used to estimate variations in corn grain yields as a function of spatial differences in soil depth and available water holding capacity in site specific agriculture. Corn grain yields were measured over a 3-yr period from 70 plots at the Cornell University Robert Musgrave Research Farm at Aurora, NY, USA. Soil depths ranged from 0.2 to 1 m. During one year of the study, paired irrigated and non irrigated plots were placed at locations that had varying soil rooting depths. Irrigation resulted in significant increases in grain yield with the greatest response occurring on the soils with less than 0.5 m of rooting depth. Yields under irrigation were similar at all soil depths suggesting that, as soil depth decreased on these soils, water was the major limiting factor. The water budget model gave satisfactory estimates of grain yields as a function of soil depth and available water capacity and appears to be a useful tool to estimate corn grain yield as a function of soil depth and available water. The estimated potential yields can be used as a guide for site specific soil management given variations in available water holding capacity that affect potential soil productivity.
All Science Journal Classification (ASJC) codes
- Soil Science