Study on Aerobic Fermentation of Dairy Manure Composting in Large-scale Farms

Use of composting is a rational processing and effective utilizing of dairy manure.In the present study,an aerobic fermentation test was conducted using dairy manure and cereal husk by means of ventilation and turning in three different groups.Group A mixed dairy manure and cereal husk at a ratio of 4:1and added 3‰ microbial fermentation agent in compost;group B added 3‰ microbial fermentation agent to dairy manure and group C,also control group,used only dairy manure.The results showed that ratio of carbon to nitrogen(C/N)was improved to 25.48:1in group A.Moisture content,organic matter,C/N ratio decreased with the composting process in successive speed from group A,B to C.C/N ratio of group A and B were reduced to 16:1or less in 28 dand 35d,while C/N ratio of group C remained 17.40:1till 35 din compost.The pH value of three groups increased at first and then declined.The content of total humic acid dropped with the composting process,and the content of total humic acid of group A,B were obviously lower than that in group C.But the ratio of humic acid to total organic carbon increased obviously.Ratio of humic acid to total organic carbon of group A,B,C were increased by40.28%,23.44%,21.67%after fermentation.Temperature in the group A,B,C rose to above 55℃respectively in the 5,9,11 dafter composting and maintained till 25,18,14 d.After 35 days of fermentation,organic matter,pH,heavy metals,total organic fertilizer nutrients of three groups kept in line with standard NY525-2012.The results indicated that adding cereal husk and microbial fermentation agent in dairy manure compost worked beneficially to maturity of manure in terms of all related physiochemical indicators.