蒸散发条件下农田土壤水盐动态简化模型

利用需水系数、蒸腾系数和潜水蒸发经验公式,引入水分迁移系数和盐分迁移系数,建立了蒸散发条件下农田土壤水盐动态简化模型。提出作物根系吸水比例系数,用以区分计算土层下边界的根系吸水项和土壤毛管水上升项。引入盐分影响下的作物蒸散发修正系数,并与水盐生产函数相反馈进行土壤水盐动态的修正。该模型简单适用,可用于蒸散发期间田间水盐状况的调控管理。

The simplified model of salt-water regimes in farm land soil under the processing of evaportranspiration

According to the principle of salt-water balance and the observation and experimental data about ground water, irrigation and salt regimes, making use of water-need coefficient and transpiration coefficient and introducing salt and water migration coefficients, this paper presents a simplified model of salt-water regimes of upper soil layer under the processing of evapotranspiration. Based on the growth function of the crop roots, a water uptake ratio coefficient of crop roots is presented also, so that divide the lower boundary water flow into root extraction and soil capillary water movement. Introduced salt modified coefficient to evapotranspiration and feedback with the salt and water production function, evapotranspiration and the salt-water regime model are modified. The model is simple and suitable for the regulation and control of water and salt regimes on farmland under the processing of evapotranspiration.