Exogenous enzyme addition affects litter decomposition by altering the microbial community and litter nutrient content in planted forest

Abstract

Abstract Litter inputs have great impacts on the soil properties and ecosystem functioning in forests. Rapid litter decomposition leads to decreases in planted forest agricultural waste and enhances the nutrient cycle in forests. The breakdown of litter and the release of various components depend heavily on enzymes. However, the effects of exogenous enzyme preparations on litter decomposition have been hardly investigated. In this study, we examined how these enzymes affected the remaining rate of litter quality, nutrient content (C, N, K), and microbial community diversity. Taking Eriobotrya japonica litter as the research object, five exogenous enzymes (laccase, lignin peroxidase, leucine arylamidase, cellulase, and acid phosphatase) were applied to litter leaves. The mass remaining rate and main nutrient content of the litter were measured during the decomposition period. The microbial diversity attached to the surface of the litter was determined after decomposition at constant temperature and humidity for 189 days. Application of laccase and lignin peroxidase increased litter degradation by affecting microbial diversity, N and K contents. Addition of leucine arylamidase leaded to an increase in N content, and decreased the quality of the litter. The cellulose and lignin decomposition rate in litters was unaffected by the addition of cellulase, laccase, and lignin peroxidase. These results indicate that exogenous addition of enzymes may alter the nutrient content and microbial community, thus affecting litter decomposition. It is imperative to investigate the effects and mechanisms of exogenous enzymes on litter decomposition for regulating decomposition of agricultural waste litter.