Abstract: Cotton slags, characteristic agriculture wastes in Xinjiang Province, were applied in the present study for composting. Cattle manure was added as conditioning agent to explore its effects on cotton slags composting, as well as to reveal the differences of physicochemical properties of material in different depths during composting. The maturity was evaluated on the basis of germination index (GI). It was shown that addition of cattle manure could accelerate the heating up of material, increase the primary fermentation temperature, and shorten the fermentation time. Compared with control, the T index (ratio between final and initial C/N) was reduced to 0.6 in advance of 12 d, and GI was increased with cattle manure added, indicating a lower phytotoxicity. The temperature in the middle layer rose the fastest and was the highest. The increase rate of TOC (total organic carbon) and decrease rate of TN (total nitrogen) in the middle layer was also the greatest, and was followed by the bottom layer and then the surface layer. Due to the easily generated anaerobic zone in the bottom layer, material decomposed slower there, and GI was the lowest before fully composting. After composting, there was no obvious difference of physicochemical properties in different depths.

Key words: cotton slags, compost, cattle manure, physicochemical properties, maturity