A single parameter is described, comprising the moisture-holding capacity of the root zone and the capillary rise, giving the total water-supplying capacity and thus being a single characteristic of the drought sensitivity of a soil. Yields on soils with different water-supplying capacity could be compared and a relation could be derived between this parameter and yields. The parameter could not be adapted to yield depressions due to high watertables. (Abstract retrieved from CAB Abstracts by CABI's permission)