封育对昭苏马场春秋草场土壤理化性质的影响

对昭苏马场封育与未封育春秋草场土壤理化性质进行测定和分析，结果表明：封育后各土层土壤容重较未封育有不同程度的减小，表层变化幅度大，差异性显著（P〈0．05），平均土壤容重比未封育草地减小5．08％。土壤总孔隙度变化趋势与土壤容重相反，封育后平均土壤总孔隙度较未封育增加2．39％。土壤含水量在7月中旬0-20cm的含水量封育草地小于未封育草地，7月末以后降水减小，封育草地土壤含水量比未封育草地大。0-10cm土壤养分含量差异均达到显著水平（P〈0．05），土壤有机质、全量养分含量封育草地大于未封育草地，而速效养分含量未封育草地大于封育草地，速效养分变化幅度较大，尤其是速效氮和速效钾。未封育草地土壤温度相对较高，各土层变化幅度均大于封育草地，封育草地土壤各层温度变化缓慢，为植物生长提供了稳定的土温条件。

Effects of Fencing on Soil Physical and Chemical Properties of Spring-Autumn Grassland in Zhaosu Horse Ranch

Soil physical and chemical properties of fencing and non- fencing spring -autumn grassland in zhaosu horse ranch were investigated, the results showed that the soil bulk density decreased about 5.08% after the grassland was enclosured, and the surface soil changed significantly. The soil prosity increased about 2.39% after the grassland was enclosured, which was opposite to the trend of bulk density. The moisture content of soil was higher in enclosured grassland than that of non-enclosured grassland in mid-July and the trend decreased after late-July because of reduction of precipitation. The contents of soil organic matters and other total nutrients were higher in enclosured grassland in comparison with that in non-enclosrued grassland, however, the trend of contents of available nutrients was opposite, especially available N and K. The soil temperature in non-enclosured grassland was higher and varied greately in each layer than that in enclosured grassland, the variation of temperature in enclosured grassland was less, which provided good environment for growth of vegetation.