Heavy Meatal Accumulation And Crops Yield Response To Agricultural Application Of Sewage Sludge Compost

With the course of urbanization has being accelerated,the sewage treatment factory will produce large amount of city life sludge waiting for dealing with every year.Since the city life sludge is rich of plant nutrition elements such as phosphorus,nitrogen, potassium,agricultural and forestry deposing has become an important way to deal with it,But the sewage sludge contains heavy metals,which maybe contaminate the field and crop quality if it dose not used efficiently.This article researched the agricultural and environmental affection by pot and field experiment,and the main purpose are: researching(1)Whether Cu,Zn,Cr,Pb,Hg,As,Ni,Cd would contaminate soil and crop quality when apply the sewage sludge compost to filed;(2)The impact on soil fertility and crop yields(3)Nitrogen and phosphorus supplying characteristic of sewage sludge compost,and the fertilization efficiency compare with urea and chicken organic fertilizer. The main conclusion are as the following:(1)In the condition of two years pot experiment Cu,Zn,Cr,Pb,Ni,Cd six heavy metals did not contaminate the soil and crop quality,when applied 50,100,200,400g sewage sludge compost every 10 kg soil respectly,and the results are the same when the compost application dose are 300,600,1200,2400 kg per hectare.(2)At the second crops growing season nitrogen recovery of sludge compost is higher than the first season,Urea form nitrogen recovery is higher than compost form during the entirety two growing seasons.But when apply 0.15 to 0.375 g net nitrogen per one kg soil the nitrogen recovery of compost form is higher than the urea form.The mineralization of compost form nitrogen of second season was higher than the first growing season.(3)The crop yield is increased significantly when applying the sewage sludge compost to the soil,the celery yields is increased by 29.07%applying compost than routine urea dosage at highest,and the amaranth yields is increased by 203%at highest.(4)The soil fertilizer was improved when applying the sewage sludge compost.The available N,P content of treatment S100,S200,S400 are increased by 8.25%,213.18%, 251.3%and 24.48%,73.40%,138.87%respectively than U1 and CK.(5)The fertilizer efficiency of 9 t sewage sludge compost join with 90 kg net nitrogen,9 t chicken organic fertilizer join with 90 kg net nitrogen is equal with 180 net nitrogen per hectare dosage.