在河西走廊中部沙区，分别于１９９７年５月、１９９８ 年５ 月和７月，给梨园树行覆宽１ ｍ ，厚１５～２０ ｃｍ 麦草。观测土壤含盐量、湿度、温度、有机质、树下杂草和梨树根系在土壤中的分布、１ ａ生枝的生长量。树行内覆草降低了０～３０ ｃｍ 土层的Ｋ＋ ＋ Ｎａ＋ 、Ｃａ２＋ 和ＳＯ４ ２－ 的含量。当土壤含水量较小时，０～１０ ｃｍ 覆草土壤含盐量随气温的变化趋势与未覆草土壤相似，但变化幅度小；土壤含水量较大时，覆草土壤含盐量与气温呈负相关。随着覆草时间的延长，单位时间内土壤有机质增长率相对减小。０～６０ ｃｍ 覆草土层根系的分布量为未覆草的２．６７ 倍，覆草有利于梨树地上部分的生长。覆草初期，树行内的１ ａ生杂草增加；随着覆草时间的延长，１ ａ 生杂草减少；梨树行覆草１８ 个月后，１ ａ 生杂草和多年生杂草数量分别为未覆草的８．６％ 和７７．８％ 。在河西走廊，果园覆草可选在５ 月至８ 月初。 In the sand area in the central Hexi Corridor, the branches of Liyuan trees were covered with 1 m wide and 15-20 cm thick grass in May 1997, May and July 1998, respectively. Observed soil salinity, humidity, temperature, organic matter, tree weeds and pear root distribution in the soil, 1 a growth of the branches. The mulching of trees reduced the content of K + + Na +, Ca2 + and SO4 2- in 0 ~ 30 cm soil layer. When the soil moisture content is small, the change tendency of salt content in 0 ~ 10 cm mulched soil with temperature is similar to that of uncrowded soil, but the variation range is small. When the soil moisture content is large, the salinity and temperature of mulched soil are Negative correlation. With the extension of mulching time, the growth rate of soil organic matter per unit time is relatively reduced. The distribution of roots in 0 ~ 60 cm mulched soil was 2.67 times of that of bare mulch, and mulching was beneficial to the growth of aerial parts of pear. In the early stage of mulching, the number of 1-year-old weeds in the tree rows increased; the number of weeds in 1-year-old weeds decreased with the extension of mulching time; the number of 1-year-old weeds and perennial weeds after pears were covered with grass for 18 months 8.6% and 77.8% of the uncultivated grass. In the Hexi Corridor, orchard grass mulch optional in May to early August.