Abstract

From June 2001 to October 2002, we investigated soil fauna in the loess soil croplands of Shaanxi Province under different fertilizer treatments. Based on a long-term fertilization experiment, we studied the effects of six types of treatments on soil fauna, including non-fertilizer (CK), abandonment (ABAND), N, P and K fertilizer combined (NPK), straw and NPK combined (SNPK), organic material and NPK combined（MNPK）, and 1.5 times of MNPK(1.5MNPK). Seventy-two soil samples were collected and 5495 soil fauna individuals were obtained by hand-sorting and the Cobb methods, belonging to 6 phyla, 11 classes, 22 orders, 61 families, 2 subfamilies, and 35 genera. The result showed that the number of individuals and groups of soil macrofauna reached their peaks in 1.5MNPK and SNPK treatment，respectively, while mesofauna peaked in SNPK and microfauna in 1.5MNPK treatments. Of the six treatments, the largest abundance of the dominant faunal group occurred in the NPK plot, the largest abundance of the most com-mon groups was in the CK plot, and the largest abundance of rare groups was found in the 1.5MNPK plot. Similarity coefficients were generally low among the soil fauna in the six treatments, especially that of the macrofauna between ABAND and other treatments, and that of mesofauna and microfauna between non-fertilizer treatment and other treatments. The results indicate that the soil fauna community was affected by different fertilizers.