旱地地膜穴播春小麦田的土壤水分状况模拟及其水分敏感系数的探讨

Study on simulation of soil moisture condition in plastic mulching and hole sowing of dryland spring wheat and it's water sensitive coefficient

根据农田土壤水分平衡原理 ,综合应用詹森 -海斯公式和缺水条件下的作物蒸散计算公式 ,模拟了旱地地膜穴播春小麦的土壤水分变化状况。模拟结果令人满意 ,其相对误差小于 5 % ,可用于旱地地膜春小麦的土壤水分监测和指导补充灌溉。同时 ,用非线性回归技术计算了旱地地膜穴播春小麦的水分敏感系数。结果表明 ,旱地地膜穴播春小麦的播种 -出苗 ,出苗 -拔节 ,拔节 -抽穗 ,抽穗 -扬花和扬花 -成熟期的水分敏感系数分别为- 0 .2 318,0 .0 5 94 ,0 .770 9,0 .32 96和 0 .0 181,说明拔节

On the principle of soil water balance, soil moisture variation in plastic mulching and hole sowing of dryland spring wheat was simulated by Jensen Hayes formula and computation formula of crop evapotranspiration under water stress. The results of simulation was satisfactory, the relative error is less than 5%. They could be used to monitor soil moisture condition and to guide supplementary irrigation. In the meantime, the water sensitive coefficient of the spring wheat was computed by nonlinear multiple regression methods. The results of the water sensitive coefficient of the spring wheat in seeding sprouting stage, sprouting stem extension stage, stem extension heading period, heading florescence stage and florescence full ripe stage are -0.2318, 0.0594, 0.7759, 0.3296 and 0.0181 respectively. The results show that the stem extension heading period is the suitable time for supplementary irrigation.