Deep Litter System for Management of Livestock Manure:I Profile Characteristics of Litter in Deep-litter System

Deep-litter systems have been developed as an alternative of managing domestic animal manure. The characteristics of the litter profiles in two deep-litter systems were investigated. The fresh system has been used to raise pig for two months, and the old system had been used for two years, but stop raising pig for one month before sampling. The litter samples were collected from the top to the bottom of litter profiles, and analyzed for physical, chemical and bacterial properties. The temperature of the litter was significantly higher in fresh system than in old system and increased with litter profiles. No significant difference in pH of the litter was detected between fresh and old systems, but the pH values decreased with litter profiles and ranged from 7.0 to 7.6. The content of soluble salinity was significantly higher in old than in fresh system, and showed more than 20 mg·kg-1 over 0~80 cm in the old litter profiles, indicating salt accumulation in the old litter system Total porosities were over 70% in both litter systems, with no effect on biodegradation of pig manure. Numbers of the fibre degrading bacterial, antinomyces and mold were higher in the fresh litter than in the old litter system. The concentration of total N was higher in old than in fresh system, but the reverse results were obtained for the concentration of inorganic N. The results suggested that the key to prolong the life of the deep litter system was to minimize salt accumulation and refresh the old system.