城郊结合区蔬菜种植地土壤性质特征

Human activity and urbanization result in urban-rural environmental gradients.Undersanding effect of the gradients on soil properties is necessary for management of the soils around urban areas.In this study,soil quality of some vegetable fields was characterized along an urban-rural gradient in shaoxing County,Zhejiang Province.Fifteen soilphysical and chemical properties were evaluated by using principal component analysis.Results showed that there was a great variation in the soil quality along the gradient.From rural to urban zones,soil organic matter,water-stable aggregates,cation exchangeable capacity(CEC),total N and P,and available K increased,whereas soil pH value decreased.In addition,Pb,Cu,Ni,Co,Zn and Cr in the soils tended to be accumulated toward the urban zone.Sequential chemical extraction showed that mobility of all the heavy metals in the soils tended toincrease from the rural to the urban zones.The variation of soil properties accounted for by the first principal component was significantly explained bythe difference in application rates of municipal wastes.

Characterization of soil quality under vegetable production along an urban-rural gradient

Human activity and urbanization result in urban-rural environmental gradients. Understanding effect of the gradients on soil properties is necessary for management of the soils around urban areas. In this study, soil quality of some vegetable fields was characterized along an urban-rural gradient in Shaoxing County, Zhejiang Province. Fifteen soil physical and chemical properties were evaluated by using principal component analysis.Results showed that there was a great variation in the soil quality along the gradient. From rural to urban zones, soil organic matter, water-stable aggregates, cation exchangeable capacity (CEC), total N and P, and available K increased, whereas soil pH value decreased. In addition, Pb, Cu, Ni, Co, Zn and Cr in the soils tended to be accumulated toward the urban zone. Sequential chemical extraction showed that mobility of all the heavy metals in the soils tended to increase from the rural to the urban zones. The variation of soil properties accounted for by the first principal component was significantly explained by the difference in application rates of municipal wastes.