新疆棉花膜下滴灌基于消退指数的土壤水分预报方法研究

Study on Soil Moisture Forecast Method Based on Exponential Depletion Relations for Cotton Drip Irrigation under Mulch in Xinjiang Autonomous Region

根据北疆膜下滴灌棉花全生育期土壤水分观测数据,研究了不同深度的棉田土壤水分消退指数随作物生长时间的变化规律,探讨了棉花生育期土壤水分预报的经验递推方法,实验结果分析表明:棉花生育期消退指数在不同深度都呈现先增大后减小变化趋势,并且随其深度的增大而减小,其离散程度也随深度有所变化;利用消退指数法对40和60cm层土壤贮水量进行预报,预报误差最小为0.16%,预报所需资料少,结果可靠,精度较高,是一种适合新疆棉田土壤水分预报的实用方法。

According to the survey data of soil moisture of cotton drip irrigation under mulch during whole growth stages in the north of Xinjiang autonomous region, the change rules of soil moisture exponential depletion relations in different depths and different growth stage are analyzed and the empirical method for soil moisture forecast is discussed. The experimental results indicate that the soil moisture exponential depletion relations in different depth show the trend of increase at first and then decrease. Moreover, it decreases with the increase of depth, and the dispersion degree also changes with the depth. Using the exponential depletion relations method, the soil water storage at the layer of 40 and 60cm are forecasted, and the minimum forecast error is 0. 16%. The method does not need much data, and its result is reliable and precise. So it is a practical method for soil moisture forecast in cotton field of Xinjiang Autonomous Region.