A simulation study of wheat crop response to water supply, nitrogen nutrition, stubble retention, and tillage

Abstract

A series of SimUlations was made with a fallow-wheat crop simulation model to examine the effects of stubble retention and tillage on yield for 2 semi-arid environments in north-western Victoria over a 100-200-year period. The fallow treatments comprised 4 combinations of stubble management and tillage in 18-month-long fallows of a fallow-wheat rotation. The 2 sites are representative of the major soil types of the region: a chromic vertisol at Dooen and a calcic xerosol at Walpeup. Stubble retention had the greatest effect on yield, providing a median increase of 0.8 and 0.6 t/ha at Dooen and Walpeup, respectively. Zero tillage had an important but small advantage in the presence of stubble..