Profile characteristics of available nutrients and heavy metal concent rations in greenhouse soils

The profile characteristics of available N,P,K and heavy metal concentrations in greenhouse soils of Shenyang suburb were studied.The results show that with the planting years going by,the available N and P have a significant increase,have a significant positive correlation with the planting years and the available K also has increased for some extent,but not so high. The contents of heavy metals copper,zinc, cadmium and lead in the protected soil of the greenhouse are higher than those of field,and with the prolongation of planting years,their concentrations are also going up,but they do not exceed the quality criterion of soil environment.