Abstract:

Ginkgo biloba is a traditional economic tree species in China, and it is often cultivated by using agroforestry pattern. In order to understand the effects of different agroforestry patterns of G. biloba on soil fertility, three agroforestry patterns were selected, including G. biloba +Wheat+Soybean (G+W+S), G. biloba+Mulberry (G+M) and G. biloba+Rape+Soybean (G+R+S), and as CK, another two planting patterns were also selected, including Mulberry (M) and Rape+Soybean (R+S). The soil chemical properties of the five patterns were determined after three years, and the soil fertility of five patterns was also evaluated by using improved Analytic Hierarchy Process (AHP). The result showed that the pH, organic matter, total N, hydrolyze N, available P, total K and available K of the soil of the five patterns were different remarkably, and these parameters at different soil layers were also different remarkably. The total N, total P, organic matter, available P and available K of soil of five patterns decreased with increasing soil depth, however, the pH increased. The organic matter, total N, hydrolyze N, available P and available K of soil in R+S were the lowest among five patterns. The result of comprehensive evaluation of soil fertility showed that the soil fertility of the five patterns were different significantly, and the values of soil fertility quality indicators (FI) of five patterns were G+W(0.973)＞G+W+S(0.424)＞M(0.388)＞G+R+S (0.255)＞R+S (0.233). Therefore, Ginkgo agroforestry could improve soil fertility.

Key words: Ginkgo biloba, agroforestry, soil fertility, comprehensive evaluation