Computer Modeling of the Effect of Root Architecture on Competition for Diffusive Nutrient Uptake With Neighboring Root Systems

摘要

When plants grow in group, competition for soil nutrient not only occurs within but also between root systems. Simulation of competition for nutrient by competing root systems is necessary to facilitate the quantitative understanding of these processes, to predict the consequences of competition for nutrients, and to prioritize future research on the mechanisms of nutrient competition. The method introduced in this paper is a new procedure for studying competition between different plant root systems (multiroot competition) by quantitatively determining overlap of depletion zone between competing root systems. The multiroot competition can be simulated as a geometric model. With this model multiroot competition was successfully separated from inter-root competition. Programs had been developed to calculate both inter-root competition and multiroot competition for diffusive nutrients like P. In the assembly of root system, subject roots and neighboring roots were defined as two components of multiple root system. Three indices were introduced to estimate and quantify multiroot competition. Result of the simulation shows that distance between roots, root shailowness and soil diffusion coefficient have significant effects on multiroot competition, and consequently affect nutrient uptake.