Effect of the composting system of hickory shell on the degradation of lignocellulose

Abstract

Three experimental groups were designed to study the effects of different exogenous nutrients on a composting process and the degradation extents of cellulose, hemicellulose, and lignin. Hickory shell was the main raw material, and spent mushroom substrate and composted chicken manure were used as exogenous nutrients. The C/N ratios of these groups were adjusted to 34 by using soybean meal. The study results showed that the duration of high-temperature stage of composting was shortened and the maturity of composting products was improved by adding exogenous nutrients. The seed germination index with spent mushroom substrate and composted chicken manure were 112% and 101%. The addition of exogenous nutrients reduced the composting weight loss and increase the degradation extents of cellulose (≥64.6%), hemicellulose (≥82.4%), and lignin (≥64.3%). In particular, the degradation of compost products with composted chicken manure was higher than that of the composting products with the spent mushroom substrate. In the hickory shell composting system, bacteria played a dominant role in the initial and thermophilic phase, and the lignin degradation is related to the quantity of fungi and actinomycetes in composting process.