The evaluation of soil elements in topsoil of the sewage irrigation area in Shijiazhuang

Abstract：In this paper soil elements in topsoil of the sewage irrigation area in Shijiazhuang are evaluated, with three aspects of soil quality taken into account. Studies suggest that elements reflecting soil fertility quality are in a rich or desirable state except for Mo, Co, alkali-hydrolyzable N, available phosphorus and effective Mo which are relatively deficient. The concentrations of heavy metal elements which can reflect the soil environment quality are all below the secondary standard limits in "soil environmental quality standard" (GB-15618-95), with the concentrations of Cu, Ni, As, Hg, Pb completely reaching the senior standard. A morphological analysis of heavy metal elements show that the bio-availability and potential harmfulness of Cd are relatively serious and hence this element may be the most ecologically harmful element in the study area. Among the elements which reflect the quality of soil health, F is in abundant or desirable state while I is in relatively deficient state.