Corn yield variation as related to soil water fluctuation and nitrogen fertilizer. I. Soil water‐yield relationships

Abstract

Abstract The objective of this work was to study the effect of plant available soil water (PAW) in different soil layers before and during the growing season on corn yields (Zea mays L.) and to determine if the soil water may be a reliable index in forecasting the grain yield. The experiments were carried out for 10 years at the same site on a deep‐permeable well‐drained chernozem with good physico‐chemical and biological properties situated in a temperate‐continental dry climate with annual precipitation of about 500 mm and wide seasonal and annual fluctuation. The results show that the maximum yields (MY) were highly correlated to water stored in the soil as well at the beginning as during the growing season. In most cases the yields were better correlated to PAW at the beginning of June (r = 0.96∗∗) than at the beginning of March (r = 0.87∗∗) or July (r = 0.91∗∗). Nevertheless, the July PAW was more efficient in terms of yield per unit of PAW. Thus, 1 mm of PAW within 0–150 cm in March, June and July 1...