Abstract: The microbial preparation EM has been used as an additive to chicken manure compcot for decompositioncomparison tests. The results show that the NH-N contents of EM treatment are 41.86% (10 days)to 56. 71 %(20days) less than that of the controls and the NH-N emitted from EM treatment reduced significantly. In the late peri-od of EM treatment composting,a relatively strong brewery fragrance could be smelled,indlcating its high efficiency ofodor control.In addition,it can shorten the pollutlon-free treatment period to 20 days. Those effects are resulted fromEM introduced outside microbials.

Key words: microbial preparation, chicken manure compost, odor control, NH-N