围封禁牧对退化草原土壤性状的影响

以希拉穆仁草原为研究对象,通过对比分析不同围封年限草原土壤机械组成、含水率、容重、孔隙度、有机质含量、碱解氮及速效磷、钾等各项指标,探讨了围封对低山丘陵退化草原土壤性状的影响。结果表明,随着围封年限的增加,草原0-20 cm土层土壤黏粒含量、孔隙度逐年增大,容重和含水率逐渐降低。随着围封时间的延长,土壤速效钾含量逐年降低,土壤有机质、速效磷、碱解氮含量逐渐增加。回归分析结果表明,土壤有机质、碱解氮、速效磷以及速效钾含量的变化同围封年限有显著的相关性。由此可见,围封是促进退化草原土壤改良及植被恢复的一项有效措施。

Effect of Enclosure and Grazing Prohibition on Soil Properties of Degraded Grassland

Taking the Sheila Muren grassland as the research object, based on the comparision of soil mechanical composition, moisture content, density, porosity, organic matter content, alkaline hydrolysis nitrogen, available phosphorus, available potassium and other indicators in degraded grassland with different terms of enclosure, the effects of enclosure on degraded grassland soil properties was explored. The results showed that with the increase of enclosed years, 0-20 cm layer soil clay content and porosity increased, but the bulk density and moisture content gradually reduced year by year in grassland. As the enclosed time going on, the soil available potassium content reduced, but soil organic matter, available phosphorus and alkaline hydrolysis nitrogen content increased gradually. Regression analysis results indicated that the change in soil organic matter, alkali-hydro nitrogen, available phosphorus and available potassium content had significant correlation with enclosed years. Thus, it can be seen that enclosure is an effective measure to promote soil improvement and vegetation restore in degrded grassland.