ALFASM: Alfalfa Growth Simulation Model

Based on the alfalfa (Medicago sativa) biological characteristics, field crop experiment and widely collected data, the alfalfa growth simulation model (ALFASM) was established. The software of ALFASM was developed.ALFASM includes crop dynamic module, water dynamic module, nitrogen dynamic module, management module, and input/output module. Crop dynamic module is the keystone among these modules. It consists of phenology, photosynthesis, respiration, leaf area dynamic, dry matter production and assimilation pa titioning, grain yield module, etc.The verification and validation of the ALFASM model has been conducted by experiment data in Beijing and Hebei province in 2000~2002. The results showed that the ALFASM simulation outcomes are very similar to the experiment data, and the ALFASM model possesses quite good simulation function. It can simulate the uptake of soil water, nitrogen and alfalfa growth biological and ecological processes such as phenology, photosynthesis, respiration, dry matter production, yield and leaf area dynamic, etc, under different climate and soil conditions. The ALFASM model provide abundant output, and it can reflect alfalfa growth and develop for simulated conditions.ALFASM system can be an important tool for scientific research, teaching and managenet decision support.The study based on plant physiology, soil physics, plant nutrition, crop cultivate and agricultural meteorology knowledge, etc and syncretize scientific research methods such as crop simulation modeL statistics and computer programming. The study brings forward the way of alfalfa growth model both home and abroad.