The simplified model of salt-water regimes in farm land soil under the processing of evaportranspiration
蒸散发条件下农田土壤水盐动态简化模型

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.