山地荒漠草地封育对土壤质量的影响

Effects of Enclosure on Soil Quality in Mountain Desert Grassland

[目的]评价封育草地土壤的质量.[方法]以北疆山地荒漠草地放牧和围封7年草地土壤为研究对象,分析土壤总有机碳、活性有机碳及碳库管理指数的变化.[结果]随着土层深度的增加土壤有机碳、土壤易氧化碳、土壤微生物量碳含量均呈降低趋势.与放牧相比,围封7年土壤易氧化碳与土壤有机碳含量升高,但差异不显著;土壤微生物量碳含量在5～ 50 cm各土层显著升高（P＜0.05）.0～20 cm、35～ 50 cm土层碳库管理指数＞ 100.表明草地封育使土壤有机碳活度增大,同时增加了土壤碳的截存,土壤质量有所提升.[结论]围封后,土壤易氧化碳与土壤有机碳含量升高;土壤微生物碳含量显著升高;土壤表层与下层碳库管理指数高于放牧;荒漠漠地长期封育改善了土壤有机质状况和土壤碳库质理,增强了土壤碳汇功能.

[Objective and Method] Taking the soil of grazing and enclosure 7 years grassland in mountain desert grassland as the research object,changes of soil total organic carbon,active organic carbon and carbon pool management index were analyzed for evaluating the soil quality of enclosure grassland.[Result] The results showed that soil organic carbon,readily oxidizable organic carbon and microbial biomass carbon content were gradually lower with the increase of soil depth.Compared with the grazing,readily oxidizable organic carbon and soil organic carbon content of enclosure for 7 years were higher,but the difference was not significant,but soil microbial biomass carbon content was significantly higher in 5-50 cm soil layer （P 〈 0.05）.Soil carbon pool management index was greater than 100 in 0-20 cm and 35-50 cm.[Conclusion] In conclusion,enclosure could increase activity of soil organic carbon,at the same time,increase soil carbon sequestration and improve soil quality.Readily oxidizable organic carbon and soil organic carbon content of enclosure were higher,Soil microbial biomass carbon content was significantly higher;Soil surface and the low er carbon management index were higher than the grazing;Desert grassland longterm nu rture and improve the soil organic matter and soil carbon library quality,enhance the funct ion of soil carbon sequestratio.