Effect Of Organic And Inorganic Matter On The Maturity And Nitrogen Conservation In Pig Manure Compost

Aerobic thermophilic composting is one of the most important method to disposal livestock manure ,but ammonia volatiliztion in composting can decrease the agricultural value of composting product and cause environment pollution problem .This paper basically studied the nitrogen changing of swine manure composting with different organic matters and the influence of chemical amendments on nitrogen changing in pig manure composting. The results followed by:1 , The four bulking agents showed significant effect on nitrogen conservation when composted with pig manure. The water-soluble NH₄—N in different four bulking agents(chaff, sawdust, straw and mushroom-dust ) co-composting with pig manure elevated gradually in the 0^th -4^th ,then it decreased dramatically until the end of composting .finally its were stable on the level of < 500ppm;The water-soluble NO₃—N in four treatments (PMC, PMS, PMST and PMMR)had the same changing trend ,in the 0-8^th its almost detected no NO₃—N but after this time the water-soluble NO₃—N in the four treatment increased rapidly and at last its were stable in the level of 600～ 700ppm;The total nitrogen of the four treatments had a certain degree reduce in 0 ⁸ and then its gradually increased until the end of composting. The total nitrogen of PMC, PMS, PMST and PMMR were 2.30%, 2.28%, 2.50% and 2.67% respectively. But the nitrogen changing level of contract treatment(net Pig Manure) was not significant.2, The four bulking agents had speeded up the maturity process in different extents. Solid-state C/N ratio , electric conduct(EC) and germinate index(GI) were the most popular criteria to evaluate swine manure compost maturity . When the pig manure compost solid-state C/N ratio <20, EC< 4ms/dm, GI>80%,its were matured . Based on the above maturity criteria and the temperature changing in composting process .water-soluble carbon, water-soluble C/N etc, PMMR reached mature at 22days after composting, PMS and PMST were both 26days, PMC estimated reach mature and stabilization after 30 days composting. Almost all the data of PM treatment could not meet the above criteria until the end of composting, so the PM treatment had not reach maturity and stabilization at last.Considered the compost matters changing and mature process , the mushroom-dust(PMMR) is the best organic bulking agent.