短期封育对伊犁绢蒿荒漠草地土壤氮及其粒径组成的影响

为探讨短期封育对荒漠草地土壤特征的影响,以天山北坡玛纳斯县、呼图壁县、奇台县伊犁绢蒿(Seriphidi-um transiliense)荒漠为对象,采用常规方法,测定了封育内外草地土壤全氮、碱解氮及其粒径组成,结果表明:封育后伊犁绢蒿荒漠草地0～50 cm土层全氮含量范围为1.16～1.82 g·kg-1,差异不显著...

Effects of Short-term Grazing Exclusion on Soil Nitrogen and Particle Size Composition of Seriphidium transiliense Desert Grassland

In order to investigate the effects of short-term grazing exclusion on soil characteristics of desert grassland,a pair experiment design was used to determine the soil total nitrogen,alkali-hydrolytic nitrogen and particle size composition of Seriphidium transiliense desert grassland in Manasi,Hutubi and Qitai counties on the Northern Slope of Tianshan Mountains.The results showed that the total nitrogen content in 0~50 cm soil layer was not significantly changed and ranged from 1.16 to 1.82 g·kg^-1,and the soil alkali-hydrolyzated nitrogen content was ranged from 20.58 to 62.35 mg·kg^-1.Compared with the control,it was significantly decreased by 14.62%in Manasi sample plot and increased by 16.76%in Qitai sample plot after grazing exclusion.However,the increase in Hutubi plot was not significant.Grazing exclusion increased the content of clay silt in 0~50 cm soil layer and reduced the content of sand.After grazing exclusion,the content of sand in Hutube and Qitai samples decreased by 6.09%and 14.86%,respectively,and the content of clay silt increased by 10.63%and 15.36%,respectively.However,soil silt content in Manas plot increased by 5.57%~7.23%.Soil total nitrogen content was negatively correlated with soil sand content and positively correlated with soil clay content,while soil alkali-hydrolyzable nitrogen content was only positively correlated with soil clay content.In general,after the short-term grazing exclusion,the soil particle size of Seriphidium transiliense desert grassland changed to fine granules,and soil total nitrogen did not improve significantly.However,soil alkali-hydrolyzed nitrogen needed to be treated differently due to regional differences.Therefore,continued grazing exclusion might be beneficial to the recovery of soil nutrients.