SIMULATION OF ROOT DEVELOPMENT BASED ON THE DIELECTRIC-BREAKDOWN MODEL

Knowing the root distribution in soil is essential for estimating wate r uptake by plant roots. It is difficult, however, to characterize and model undisturbed root systems. Root development in a two-dimensional potential field is simulated with the dielectric breakdown model (DBM ), which implies a similarity between electric discharge and root dist ribution. A weighted potential gradient with an exponent II was used t o create probability distributions of root growth. Each root was gener ated step-by-step by selecting random numbers from probability distrib utions. Simulations were performed for point sources and horizontal li ne sources. In both cases, as eta increased, the root system changed f rom a cluster and dense type to a slender and sparse type and the frac tal dimension decreased. For a point source of water, there was a defi nite pattern of root development toward the source. It is concluded th at the DBM effectively describes root development under various water conditions.