Studies on the Tendency of Soil Environmental Quality in Suburban Vegetable Base of Chengdu

Surveys has been developed for the quality of the soil environment in the vegetable plot, choosing some vegetable bases in Chengdu´s suburb- Pengzhou as the study area. In order to analyze the changing trend of soil environmental quality in the suburban vegetable base, comparisons from the soil pH, soil nutrient composition, soil heavy metals to pesticide residues have been made with the previous results which were published in the Second National Soil Survey in 1984. The results show that compared with 1984, nowadays (2009) the soil pH is significantly declined and the soil (pH ≤ 6.0) accounts is nearly as much as 82.35% of all the soil studied in Pengzhou; as for the nutrient content, total nitrogen, ammonium nitrogen, available phosphorus and potassium in the pick-up soil have been improved respectively, while the organic matter content has been lowered obviously; in the heavy metal content survey, almost all the kinds of metal involved here are increased except Hg. The conclusion can be made: in recent 25 years, the soil environmental quality of the vegetable base in Pengzhou is overall becoming worse and worse.