Studies On Sludge Aerobic Compost And The Application On Ameliorating The Turf In The Greenbelt

In order to solve the problems of sludge disposal, improve the quality of urban turf soil,the study of high-temperature aerobic composting for sewage sludge were conducted, in wichcorn stalks and pine sawdust were used as sludge conditioner Furthermore, the turf soilimprovement experiment with the sludge compost as soil amendments were carried out. Threeapplication methods included blending(H), the mulching(F), blending and mulching(HF), twolevels at2cm and4cm of mature ludge compost were designed in the experiment. The mainresults are as follows.1Sludge+sawdust (1:1) achieved the best composting effect, followed by sludge+sawdust (2:1), the composting effect of sludge+corn stalk (1:1) was poor.2Sludge compost application on soil can decrease soil bulk density, promote waterinfiltration, increase soil water content and improve soil physical properties. Among the threeapplication methods, HF is best, H and F have poor performance. All the three applicationmethods of sludge compost can also increase soil organic matter, Total N, available N,available P, available K in the upper layer soil. H has the greatest influence on soil nutrients,followed by HF. The effect on soil physical properties and nutrients is better with the increaseof applying sludge compost content.3Significantly increase soil carbon pool management index (CPMI), among the threeapplication methods, H is the highest, next is HF. The H4treatment has the highest CPMIwhich is2.5times higher than CK, followed by HF4treatment which is2.2times as much asCK.4Sludge compost application on soil can increase the content of Pb，Cr，Cu，Zn in thetop layer of soil, respectively. The concentration of heavy metals increase higher with theincrease of applying sludge compost content, but all treatments have no effects on the contentof heavey metals below40cm soil depth. And the concentrations of these elements all arewithin the limits of Environmental Quality StandardⅡ, soil environment are not contaminated,reaching the "clean" and "safe"levels.5The application of sludge compost to soil can significantly increase soil microbialbiomass C and N, increase activities of the urease, invertase and alkaline phosphatase activity, and the increase is opositively related to the content of sludge compost. Contrast with eachapplication methods, soil microbial biomass C, N and soil enzyme activity in HF and H aresignificantly higher than F.6The application of sludge compost can promote the growth rate, tiller number,belowground biomass, and improve appearance quality of lawn, both F and HF achieve thehigh appearance quality, H is slightly worse than F and HF. More sludge compost content,better lawn appearance quality. Furthermore, F4, HF4and F2can suppress weed growth, therate of growth suppress are91%,87%and84%respectively.