Abstract: In order to explore the ways for promoting litter decomposition in urban protective greenbelts of arid zone, litter falls were collected from the protective greenbelts in north suburb of Karamay, Xinjiang, and a composting experiment with the inoculation of three kinds of microbial agents, i.e., Qingzhu, Jiegan, and Sufu, was carried out for 198 days in late October 2007. At the early stage (0-30 d) of composing, inoculating microbial agents promoted the decomposition of the litter falls, and the effect of Sufu agent was significant, compared with CK. The N, P, and Ca concentrations in the composing litter falls increased persistently with time. By the end of the experiment, the nutrient concentrations in the composed litter falls were 14.2%-252.9% higher than their initial values. During the whole composing process, the decomposition rate of the litter falls organic C increased continuously, and the C/N ratio decreased gradually. It was suggested that inoculating microbial agents could accelerate the composting process, and increase the nutrient concentrations in composted litter falls. Among the three test microbial agents, Jiegan agent was the best one.

Key words: litter fall, composting, nutrient, microbial agent, forest plantation, potato, soybean, intercropping, photosynthetic characteristics, yield, compensation effect.