Effect of effective microorganisms on composting characteristics of chicken manure

H.K. Ong, B.H. Chew and M. Suhaimi

Abstract

A composting trial using nine windrow piles of broiler manure was conducted under non-ideal and non-aerated conditions without carbon/nitrogen adjustment to study the effect of effective microorganisms (EM) and Bokashi on composting process and ammonia emission. There were three piles per treatment, with the treatments being a Control, EM-treated and Bokashi-treated. The product EM was a mixture of microbial inoculum in a solution of lactic acid bacteria maintained at pH 3.0–3.5. EM was added in liquid form while Bokashi was also EM-inoculated but in a solid medium of rice bran, burnt rice hull, coconut coir dust and chicken manure. The compost took 7 weeks to stabilise. Moisture loss was about 50%. Carbon losses were 9.0, 10.9 and 9.2%, while nitrogen losses were 17.5, 18.8 and 22.7% respectively for control, EM-treated and Bokashi-treated composts. There was an increase in pH from 6 initially to 9 at the end of composting.Concentrations of other elements including heavy metals were increased at the end of composting due to loss of mass. Ammonia emission was highest in Bokashi-treated piles. Maximum ammonia emission was found at about 15 days of composting. The addition of EM did not shorten the composting period. Based on result of ammonia emission, there was also no evidence to suggest that EM addition reduces odour.

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