腾格里沙漠南缘沙漠化逆转过程中的土壤化学性质变化特征

在腾格里沙漠南缘,应用空间代替时间的方法,选择了流动沙丘、封育5 a、封育15 a和封育25 a样地的恢复演替序列,代表沙漠化逆转的不同阶段,研究了干旱区沙漠化逆转过程中的土壤化学性质变化特征。结果表明,腾格里沙漠南缘沙漠化逆转过程中,0-300 cm土壤pH、电导率、速效磷、速效钾、全氮、有机质呈现不同程度的波动变化,但均值持续增大;各阶段表层土壤pH逐步减小,而电导率和代表土壤肥力状况的速效钾、速效磷、全氮、有机质在封育恢复过程中均持续增大,且各阶段表层土壤化学性质总体差异显著。研究认为,腾格里沙漠南缘的沙漠化逆转过程,是土壤化学性质逐步向良性化方向发展的过程,是土壤的形成与改良过程。

Variations of Soil Chemical Properties in Reversion Process of Desertification at the South Edge of the Tengger Desert

At the south edge of the Tengger Desert,chose the moving dune,enclosure for 5 years,enclosure for 15 years and enclosure for 25 years of the restoration successive series,It represents the different stages of reversion process of desertification.The soil chemical properties of the decertified land were studied in reversion process of desertification with the method of substituting time with space.The results showed that the soil pH,soil electrical conductivity,soil available potassiumat,soil available phosphorus,soil total nitrogen and soil organic matter showed varying degrees of fluctuation changes at depth of 0-300 cm,but the mean valuehave increased continuously.Surface-soil pH gradually decreased in reversion process of desertification,but surface-soil electrical conductivity and soil fertility on behalf of soil available potassiumat,soil available phosphorus,soil total nitrogen and soil organic matter gradually increased in reversion process of desertification,and the overall difference of the surface soil chemical properties in various stages was significant.It is concluded that the soil chemical properties gradually develop in the benign direction in reversion process of desertification at the south edge of the Tengger Desert.