基于水量平衡方程推求盐分胁迫条件下春玉米根系吸水模型参数

The calculating of the root water uptake model parameters of spring maize under salt stress conditions based on water balance equation

为了探究作物根系吸水与根区土壤盐分运动的关系,在甘肃省石羊河流域开展春玉米田间试验,试验在测坑中进行,引入Feddes提出的根系吸水模型,在春玉米生育期内选择7个时间段作为研究春玉米根系吸水时间段,设置淡水灌溉、3 g/L水与6 g/L水灌溉处理,利用水量平衡方程分别计算各处理在各时段的根系吸水量.在此基础上,利用最小二乘法优化得到盐分胁迫修正系数的参数p为1.397,并且对3 g/L水与6 g/L水处理的根系吸水量模拟值和实测值进行了比较,相关系数在0.99以上,模拟值和实测值的误差在允许误差15%范围之内.建立了盐分胁迫条件下春玉米根系吸水模型,为该地区研究春玉米种植条件下土壤水盐运动规律奠定基础.

In order to study the relations between the root-water-uptake of crop and soil water salt transport in root zones,field experiments were conducted under the conditions of spring maize growth in Shiyang River Basin of Gansu province. The field experiments were carried out in test-pits. It was introduced into the root-water-uptake model,which was proposed by Feddes. During the growing period of spring maize,the seven time periods were selected to study the root-water-uptake of spring maize. Fresh water,3 g/L and 6 g/L irrigation treatment were set up in field experiments. The root-water-uptake content of each treatments at different period was calculated using water balance equation. The parameter（ p） of salt stress reduction function was optimized by the least square method and the parameter（ p） was 1. 397. The root-water-uptake content of 3 g/L and 6 g/L irrigation treatment was simulated and compared with measured value. The correlation coefficient was above 0. 99 and the error between the simulated and measured values was within the allowable error range of 15%. It establishes the root-water-uptake model of spring maize under salt stress conditions. This model is conducive to understanding of the law of soil salt movement under spring maize growth.