Three-dimensional dynamic simulation of the rice root system under different phosphorus concentrations

Phosphorus is a vital element for plant growth, and it exerts a significant influence on the growth, development, and yield of rice. In order to study the dynamic growth status of rice roots under different phosphorus concentrations, this paper takes the roots of two rice varieties, HuaJing (HJ) and Metzam (MTZ), as the research objects, simulate the growth of the root system under phosphorus deficient (LP), 50% phosphorus (MP), and normal phosphorus (HP) conditions, and proposes an L-system-based three-dimensional rice root-environmental growth model DRoots, which employs the idea of the operator-splitting approach to the extended movement of soil phosphorus and the root growth of the two processes are modelled separately, and then they are coupled by iteration. Root growth is simulated in a rectangular geometry planter during root growth modelling, and collisions between roots and between roots and the inner wall of the planter are considered. The root growth of two varieties of rice at different phosphorus concentrations was compared by three-dimensional dynamic simulation studies, which analysed the existence of differences in the phosphorus demand and response of the root systems of the two varieties of rice from different perspectives, as well as the correlation between the indicators of each parameter. The results showed that these parameters were significantly correlated with each other, and thus the model could simulate the growth of rice root system more accurately. This study provides a reference for other crop root systems to explore the mechanism of phosphorus effect on rice root growth.