长期施肥对黄土区农田土壤动物群落的影响

 2001年7月至2002年10月，采用手捡法和Cobb过筛法,对陕西黄土区6种长期施肥，即对照组（不施肥，CK）、撂荒（不施肥、不耕种，用ABAND.表示）、施氮磷钾（NPK）、施氮磷钾+秸秆（SNPK）、施氮磷钾+有机肥（MNPK）和施1.5倍（氮磷钾+有机肥）（1.5MNPK）与农田土壤动物群落间相互关系进行研究。两年4次共采集72个定点土壤样品，获农田土壤动物标本5 495只，隶属6门11纲22目61科2亚科35属。调查结果表明，不同施肥处理对土壤动物的影响差异性显著（F = 2.24，P＜0.007)。土壤动物数量变化与长期施肥导致土壤性质的变化有关。主成分分析表明，SNPK、NPK、MNPK和1.5MNPK对土壤动物类群的影响能力显著不同，SNPK和NPK对土壤动物优势类群有正向作用，而MNPK和1.5MNPK则相反，对其它的解释不明显。从第一主分量看，各种施肥处理对土壤动物个体总数的综合影响最明显，对土壤动物群落均匀性、多样性影响最小；从评价值大小看，第一主成分特征向量最大值和最小值之间相差较大，表明6种施肥对农田土壤动物的影响不平衡。

Effect of Long-Term Fertilization on Cropland Soil Fauna Community in Loess Soil, Shaanxi, China

The relationship between long-term fertilization and cropland soil fauna was studied at the station's experiment research network for soil fertility and fertilizers in Shaanxi Loess soil from Jul. 2001 to Oct.2002 in Shaanxi. Six types of long-term fertilization were carried out in this study including control (CK), abandonment (ABAND.), nitrogenous and phosphorus and potassium fertilizers (NPK), straw and NPK (SNPK), organic material and NPK (MNPK) and double MNPK. Seventy-two soil samples were collected and 5 495 species of cropland soil fauna were obtained by handsorting and Cobb method at 4 times, belonging to 6 phyla, 11 classes, 22 orders, 61 familia, 2 superfamilia and 35 genus. The result showed that different fertilization had significant effect on cropland soil fauna (F = 2.24，P <0.007). The number of crop soil fauna was related to soil physicochemical properties caused by long-term fertilization. The result of principal component analysis, focusing on the number of 15 key soil fauna species group's diversity, evenness of community and the total soil fauna individuals, indicated that the effects of SNPK, NPK, MNPK and 1.5MNPK were significantly different on cropland soil fauna, in which, SNPK and NPK had a positive effect on cropland soil fauna，and MNPK and 1.5 MNPK had a negative effect, others cannot been explained. By principal component Ⅰ, the synthetic effect of different fertilization on the total soil fauna individuals and the group was most significantly, and the effect was little on evenness and diversity. By value of eigenvectors, the maximum one was 9.6248, and the least one was -1.0904, which means that the effects of six types of fertilization on cropland soil fauna are unbalance.