Abstract:

Studied the soil fertility on south slope in Qinling Mountains,the spatial distribution and variation pattern and its relation with altitude. The results showed that the spatial distribution range of soil fertility in Qinling forest area on south slope was soil pH volue 5.97～6.89,organic matter 6.6～50.1 g·kg^-1, total N 0.5～3.8 g·kg^-1 ,available N 33.6～257.3 mg·kg^-1,available P 0.81～5.8 mg·kg^-1,available K 38.9～262.4 mg·kg^-1,clay particle content 11.3%～18.1%,capacity of exchangeable base 68.5～310.2 mmol·kg^-1 respectively; The spatial variation degree of available P, organic matter, and total N was big,whereas clay particle content and active acid pH value was small;the spatial variation degree of soil pH value, organic matter, available P, clay particle content, and capacity of exchangeable base decreased with the deep of soil,whereas soil total N、available N, and available K increased. The horizontal spatial variation degree of soil available K、available P and capacity of exchangeable base influenced much more by altitude,whereas soil pH value and clay particle content influenced less. The soil pH value decreased with the altitude, whereas organic matter and available P、K increased;The soil fertility spatial variation decreased as the altitude went up, which may have something to do with mankind disturbance strength lowering and forest type inclining to sameness.

Key words: south slope in Qinling, soil fertility, space distribution and variation, altitude