西北枣林土壤水分自然修复及其模拟

以节水型修剪下矮化密植枣树为研究对象,设置4种不同初始土壤含水率,在雨养条件下连续2 a观测土壤水分、生物量,结合HYDRUS 1D模型分析评价了林地水分修复。结果表明,自然降雨条件下,4个小区土壤水分趋向一个稳定值,该值大小取决于当年降雨量。基于HYDRUS 1D模拟的枣园土壤水分相对误差为1.52%,均方根误差未超过0.5,决定系数平均达94%,说明该模型在该地区具有较好的适用性。HYDRUS 1D模拟节水型修剪下的枣林土壤水分显示在今后60 a可以保持多数年土壤水分处于良好水平。

Self-recovery of Soil Water in Jujube Orchard in Northwest China: Experiment and Numerical Modelling

A two-year field experiment was conducted to study the dynamics of soil moisture and biomass in a in-tensively cultivated and rain-fed jujube orchard. We pruned the jujubes to control their height. Four different ini-tial soil moistures were examined. We then simulated the soil water dynamics using the HYDRUS 1D software. The results showed that, under natural rainfall condition, the dynamic patterns of the soil water under different ini-tial moistures were the same, differing only in their absolute values. The error of the results simulated from the HYDRUS 1D was only 1.52%compared with the measurement, with the RMSE less than 0.5 and the coefficient of determination being 94%. The results predicted using the model reveal that, by pruning the jujubes to save wa-ter, the moisture content in the orchard can remain at a good level for the jujube to grow in most time of the next 60 years, and that pruning can improve water use efficiency.