Water Use by Maize at Three Plant Densities

Abstract

SUMMARY Water use by maize at three densities was measured by a complete water balance, including soil moisture, rain, applied irrigation and deep drainage in crops irrigated so that relative turgidity at noon remained above 90 per cent (i.e. no-stress conditions). Total evapotranspiration between planting and harvest, 56 cm., was not significantly affected by density, but evapotranspiration was slightly higher at higher densities when ground cover was less than 50 per cent. Actual evapotranspiration rose to 1 cm. per day during anthesis and grain filling. A fifth of the water applied moved beyond the root zone, indicating that work on more permeable soils would be inaccurate if the deep drainage component was ignored.