Abstract:

Soil nematodes are useful as indicators of soil health. To understand the contribution of overuse of pesticides to soil pollution, we investigated the total number and relative abundance of soil nematodes in several different land use types with different degrees of pesticide use. These different land use types, found inside and outside the factory of Anhui Huaxing Chemical Industry Co., Ltd. in Hexian county, Anhui Province, China, include bare land inside the factory (BIF), stands of pagoda pine (Pinus armandii) trees inside the factory (PIF), bare land outside the factory (BOF), soybean field outside the factory (SOF), paddy field outside the factory (POF), and corn field outside the factory (COF). Soil nematode numbers varied greatly among landuse types, and when ranked in order of greatest to lowest number were PIF>SOF>COF>POF>BOF>BIF. Total count of soil nematodes was higher in lands with vegetation than in bare lands (P<0.01). The number of trophic levels except bacterivores and predators/omnivores were higher in areas with vegetation coverage. Land uses with vegetation coverage had the largest number of plant-parasites while bare land had the largest number of bacterivores. Relative abundance of plant-parasites of PIF was 84% while relative abundance of bacterivores of BOF and BIF were 74% and 72%, respectively. Taken together, these results indicate overuse of pesticides has an effect on the amount and relative abundance of soil nematodes, and an important role for vegetation coverage in mitigating environment pollution.

Key words: pesticide, nematode, bio-indicator, different land use types