sewage sludge is rich in organic matters and nutrients including N and P. therefore, the application of composted sludge in barren loess is supposed to inevitably improve the content of organic matters in the loess, add necessary nutrients for the growth of plants, and increase dry weight of plants. meanwhile, because the composted sludge belongs to aggregate structure with weak acidity, its application can reduce the alkalinity of loess and improve soil environment, which is beneficial for the plant growth. after planting, significant correlations were found between the heavy metals contained in soil and the organic matter and ph of soil. particularly, the organic matter was extremely correlated with Cd with their contents respectively as 0.995 and 0.997 in the soils of corn and wheat. the analysis results are illustrated in table 4.