Utility of a simple soil water budget model in agronomic research. 1. Effects of plant density, time of sowing and fallow water on available soil water under spring wheat

Abstract

A simple soil water budget model was used to estimate weekly changes in available soil water as affected by plant density, time of sowing and level of available fallow water for spring wheat cultivars grown on a black earth in northern New South Wales. Estimated values of available water were mostly within ±10 mm of observed values (ranging from 50-270 mm) obtained at four intervals during the growing season. The results are discussed in relation to both the interpretation of agronomic field experiments and use of the model in regions where conserved fallow water contributes significantly to cereal production.