NOTE SIMULATION OF ROOT GROWTH AND ITS EFFECT ON THE PATTERN OF SOIL WATER UPTAKE BY A NONUNIFORM ROOT SYSTEM

Abstract

An approach is described toward evaluation of the effect of root growth on soil-water-plant relations in the context of a dynamic simulation model of moisture extraction by a nonuniform root system. The method accounts for root proliferation in each layer and of root extension into deeper layers, the rates of which are assumed to depend on soil moisture potential. The death rate of roots in each layer is also taken into account. The overriding importance of root extension as a factor prolonging the period of time a plant can continue to thrive on the unreplenished reserve of moisture contained in an initially-wet soil profile was demonstrated.