On the basis of the theory about the kinetics of crop growth, this paper develops a model to express soil water-integrated dry-matter accumulations in roots and shoots, and their mutual relations. It compares the simulated and actually measured accumulations of dry matter in roots and shoots, illustrating that the simulated and actually measured values tally with each other and significantly correlate with each other at p=0.01, which proved the model presented by the paper reasonable and logical. This model...