The Root Growth And Distribution Model Of Winter Wheat

This study was based on laboratory soil column cultivation experiments. Experiments had been completed in the soil-plant system simulation laboratory of source and environment department in China Agriculture University. Designing soil column cultivation experiments of winter wheat under different conditions of water supply (traditional irrigation and subirrigation )and different water treatments(traditional irrigation A1, traditional irrigation A2, subirrigationB1, subirrigationB2) to study the root growth and distribution rule of winter sweat under these conditions. The results achieved in the experiments were as follows:1. As the statistic result about wheat normalized root length density distributions Lnrd(zr) (Zuo et al., 2004) was only based on the condition of traditional irrigation, this experiment showed that this statistic result is available for subirrigation condition.2. Based on this experiment, wheat root growth distribution model advanced by Asseng et al (1997) was built, this model could simulate the wheat rooting depths well, but the simulated root length density distributions had a large difference with the measured datum.3. Based on the rooting depths and the root length in different stages and water treatments of winter wheat which were simulated by the model advanced by Asseng et al(1997), roots were distributed in the root zone in the way of the statistic result of wheat normalized root length density. Results showed that the improved wheat root growth distribution model simulate the wheat root growth distribution better than original model.4. The original root growth distribution model involved many parameters which are difficult to obtain. Firstly, based on three constants of winter wheat(Water Utilization Efficiency WUE, Specific Leaf Weight SLW and Specific Root Length SR) , we calculated the wheat root length of different stages and water treatments according to transpiration and leaf area easily measured. Later, the distribution of wheat root length density in root zone were simulated according to the statistic result about the wheat normalized root length density and the model advanced by Asseng et al (1997). An efficient wheat root growth distribution model was built completely.