Changes of Temperature and Nutrients in Cow Dung with Different Amendments During Composting Process

Composting cow dungs is an effective way to dispose the wastes. However, different amendments greatly affect nutrient transformations during composting process. In this experiment, urea, oil residue, bean cake and two types of fermentation agents were added to the mixture of cow dung and straw materials to examine changes in temperature, acidity of compost product and contents of nitrogen and phosphorus. Additions of fermentation agents could increase temperature of cow dung compost, bringing the compost to high temperature phase quickly and extending the high-temperature duration. Composting increased total nitrogen contents. Adding our own developed fermentation agents led to greater nitrogen contents, but reduced the ratios of NH+4-N to NO-3-N, thus having the compost matured in 21 days(NH+4-N/NO-3-N≤0.5). In addition, the fermentation agents also promoted the transformation of inorganic into organic phosphorus and improved the ratio of organic phosphorus to inorganic phosphorus of the compost products. Considering both nitrogen conservation and compost maturity,different amendments were in order of our fermentation agentscommercial fermentation agentsbean cakesoil residuesurea.