Simulating root growth dynamics

Abstract

We present a simple root-growth model that is capable of reproducing root distribution patterns as conditioned by varying soil conditions. The model assumes that the lateral growth of roots at any depth is governed by two factors: (i) the current root mass or root-length density at a given depth, and (ii) an environmental factor that may limit the further growth of roots at that depth. Using the relative soil-water content as the environmental factor, it is shown that an exponentially declining root distribution, commonly observed under wet soil profiles, can be reproduced by the model. Other non-exponentially declining root profiles observed under spatially varying soil-water contents can be simulated. The results indicate that the simple root model is capable of predicting differing root growth and distribution patterns, consistent with empirical observations under varying soil conditions.