Corn Yield Response to Excessive Soil Water Conditions

Abstract

ABSTRACT DATA from a long-term field drainage experiment in Ohio were analyzed to develop a relationship be-tween relative yield and stress day index (SDI). The water management model, DRAINMOD, was modified to compute SDI for four treatments for each of the 12 yr of the experiment. Relative yields were obtained for each case by dividing the measured yield by the potential yield. Results of the study showed that there is a strong rela-tionship between relative yield and stress day index for corn. A linear regression line was fitted to the data and the regression model was tested against three other sets of data from the literature two from India and one from Iowa. The model was in good agreement with results from the independent experiments even though there were wide differences in soils, climate and experi-mental conditions. Statistical tests showed that relation-ships for relative yield vs. SDI, obtained from the four in-dependent experiments, were from the same population, and that the Ohio regression model could be used for all conditions considered.