宁南山区不同放牧强度对天然草地土壤水分的影响

本文对位于宁夏南部黄土高原半干旱区过渡放牧区、中度放牧区和持续禁牧三种条件下的天然草地 0 - 9.9m土壤深度的水分含量进行了测定。三者土壤水分含量的主要差别在 0 - 4m以上土层。 0 - 4m土层的土壤湿度 ,核心保护区显著 ( p =0 .0 2 2 838)高于中度放牧区 ,极显著 ( p <0 .0 0 1 )高于过渡放牧区 ,中度放牧区也显著高于过渡放牧区 (p =0 .0 2 80 2 3)。平均土壤湿度 ,核心保护区分别是中度和过渡放牧区的 1 .2 5和 1 .5 6倍 ,中度放牧区是过渡放牧区的 1 .2 5倍。 4- 9.9m土壤湿度 ,核心保护区、中度放牧区和过渡放牧区没有显著差异 ,平均土壤湿度分别为 1 2 .3%、1 2 .7%、1 2 .7%。

Effects of Different Grazing Intensities on Soil Moisture of Natural Grasslands

This study tested soil moistures in soil depth of 0-9.9m on three natural grasslands of overgrazed, moderate grazed and continuous protected from grazing respectively in the semi-arid area of south Ninxia, Northwest China. There were significant differences in soil water moisture in soil depth of 0-4m among the three lands, but no significantdifference existed in soil depth of 4-9.9m. Soil moisture in continuous protected grassland was significantlygreater than that of moderately grazed grassland (p=0.022838)and most significantlygreater than overgrazed grassland (p<0.001), and the soil moisture in the same soil depth of moderate grazed grass land was also significantly greater than overgrazed grassland (p=0.028023). The average soil moisture of the protected grassland in 0-4m was 1.25 and 1.56 times greater than moderate and overgrazed grasslands respectively, and that of moderately grazed grassland was 1.25 times greater than overgrazed grassland in the same soil depth of 0-4m. In the soil depth of 4-9.9m, average soil water moistures of protected grassland, moderately grazed grassland and overgrazed grassland were 12.3%, 12.7% and 12.7% respectively.