Accumulation and spatial variability of heavy metals in soil-crop system around a chemical factor in northern Shaanxi province

• 1、College of Natural Resources and Environment, Norhtwest A&F University, Yangling Shaanxi 712100

Abstract：In this paper, accumulation and spatial variability of Cu, Zn, Pb and Cd in soil-crop system around a chemical factor in northern Shaanxi province. Results show that wastewater irrigation led to Cd and Cu accumulation in soils, and concentrations of Cd was higher than the critical of soil environmental quality (II). All the heavy metals were mainly accumulated in the top layer (0-20cm). Spatially, soils and plants high in heavy metal concentration were distributed within the radius of about 100 m to 200 m from the waste water outlet, and decreased exponentially with the distance from the factory. Affected by wastewater irrigation, contents of Cd and Pb in maize were significantly higher than the control area, and affected by the vehicle exhaust, the over standard rate was 8%. All the heavy metals not showed significant correlation between soil and crop, except Cd. Therefore, the chemical factor has contributed to the accumulation of heavy metals in the soil around it, but no higher contribution to the crop, and no threat to human health temporarily. But more attentions should be put on to the higher accumulation of Pb in the maize caused by the vehicle.

Keywords： soil science heavy metal soil crops spatial variance wastewater irrigation