Ameliorating Topsoil Conditions by Biosolid Application for a waste Landfill landscape

Sanitary landfills, created for the disposal of solid waste, usually are developed into parks afterthey are closed. However, soil amelioration with organic matter is usually needed to restore fertility andpromote revegetation. Sewage sludge creates a massive waste disposal problem. The use of composted sewage sludge (biosolid) as a soil conditioner might restore the soil fertility at landfill sites and simultaneouslyalleviate the need for sewage sludge disposal. We applied biosolid to waste landfill soil and evaluated its effects on soil properties and tree growth in a field experiment. Biosolid improved soil characteristics including moisture, organic matter, and nitrogen content and also increased tree height and diameter at breast height.Physiological measures, such as chlorophyll content and photosynthetic rate, showed positive responses intrees grown in biosolid treatments. Heavy metal concentrations in soil and tree leaves after applying compost did not differ from concentrations measured at control sites. Therefore, we conclude that the use of biosolid in waste landfills would be an efficient, environmentally beneficial, and cost-effective method to restore the conditions of landfill soil for plants.