Effect of Spent Mushroom Compost on Nutrient Transformation of Litter Compost

The effect of the spent mushroom compost on nutrient transformations during litter composting was evaluated by studying the nutrients transformations of litter compost in a cylindrical composting barns for 50 days through batch forced aerated static pile model under the treatments with and without spent mushroom compost(SMC) added (treatment I and treatment Ⅱ). Changes of temperature, pH, electric conductivity, NH4+-N, NO3--N, organic matter, volatile solid, total nitrogen, total phosphorus and total potassium during composting were determined. The results indicated that when the ventilation quantity was 0.20 m3·h-1 and time of ventilation was 20 min·h-1, the temperature in treatment Ⅱ was up to 50 ℃ but was still 46 ℃ in treatment I after 35 h, and the duration of the temperature above 50 ℃ was up to 96 h which was longer than that in treatment Ⅰ by 24 h. Spent mushroom compost added increased the degradation of the organic matter, decreased the loss of nitrogen, increased total K accumulation and the concentration of nitrate, decreased electric conductivity and accelerated maturity. The total P, pH and C/N ratio during composting were not affected significantly. Obviously, adding spent mushroom compost could increase the degradation of litter compost and accelerated the maturity of compost.