Process of high-temperature compost of sheep manure with addition of wheat straw

The effect of wheat straw on sheep manure high-temperature compost was studied. Results show that addition of wheat straw during sheep manure composting shortens the time to high-temperature fermentation, decreases nitrogen loss and accelerates rate of C/N decline. During composting, high-temperature fermentation layer diffuses from the middle to upper and lower layers. At the initial stage, a positive proportional relation exists between the loss rate of organic matter and wheat straw ratio. At late composting, however, a relatively inverse relationship is observed. At the end of the sheep manure/wheat straw composting, total phosphorus and potassium, and available phosphorus and potassium in all treatments increase over the initial stage by 2.29%~8.41%, 12.51%~24.88%, 1.77%~31.34% and 5.03%~25.45% respectively. The magnitude of the increase is highest under 6︰4 of sheep manure to wheat straw. Available nitrogen drops at the end of composting by 34.62%~14.10% over the initial stage, with the lowest drop under 6︰4 of sheep manure to wheat straw. For practical applications, the ratio 6︰4 of sheep manure to wheat straw is more suitable for composting. Using a germination index of 80% as evaluation index, the mixture of 6︰4 of sheep manure to wheat straw increases composting velocity by one fold over pure sheep manure, reaching thorough decomposing after 28 days of composting.