Nitrogen Conservation of Calcium Superphosphate in Swine Manure Compost
WENG Jun-ji(Agricultural Products′ Quality and Safety Inspection Center,Sanming,Fujian 365000)
[Objective] The research was conducted to reduce the nitrogen loss of co-composting of swine manure and rice bran.[Method] Static forced-aeration composting reactors were used to study the effects of calcium superphosphate on reducing nitrogen loss of co-composting of swine manure and rice bran.[Result]Calcium superphosphate could increase compost temperature,reduce pH obviously,increase the contents of soluble NH4+-N,reduce the amounts of NH3 emission and postpone the maximum period of NH3 emission.Compared to the control,1%,2% and 3% of calcium superphosphate could reduce nitrogen loss by 33.56%,49.18% and 52.88% respectively.Calcium superphosphate addition could also increase phosphorus contents of compost.[Conclusion] The optimized ratio of calcium superphosphate usage for composting was 2%-3%.