Using the methodology of "the temporal for the spatial"

this paper studies the relation of soil physicochemical properties and soil enzymatic activities with plant organic C and total N in different desert lands in Yulin Prefecture

North Shaanxi Province.Results showed that with the process of increasing desertification

soil physicochemical properties changed regularly.At the same time

soil pH value in different profiles at the same desertification degree increased with soil depth increasing and soil urease activity was reduced sharply although the variation of soil pH value was not so obvious.Soil catalase activity in the whole profile was relatively higher and it first decreased and then increased with profile depth increasing.Correlation analysis showed that in the study area

there was little relevance between soil pH value and other factors and a close correlation among all factors except soil pH value.Except plants and the soil C/N value

the correlation between soil bulk density and other indexes was negative and the correlation among other indicators was positive.