Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8846466 | Acta Oecologica | 2018 | 6 Pages |
Abstract
Decomposition of plant litter during the freeze-thaw season has recently gained attention as having a significant role in nutrient cycling in many cold ecosystems. However, few studies have examined decomposition of crop remnants during the freeze-thaw season in an agronomic setting when microbial activity is presumably low. We examined decomposition of four cultivars of sorghum (Sorghum bicolor) leaves in a field in Southern Minnesota, USA using the litterbag method. Three of the four cultivars we examined expressed the brown midrib (bmr) mutation which have altered/reduced levels of lignin in their secondary cell walls compared to the wild-type (WT). Litter was buried in the fall and harvested during the spring thaw. After 160Â d the bmr mutants lost 57-62% of their initial mass, compared to 51% in the WT. Mass loss agreed with presumed initial litter quality, as the bmr litter had higher initial N, and holocellulose:lignin and lower lignin, C:N and lignin:N values compared to the WT. The increased decomposition of the bmr cultivars appears to be related to increased loss of hemicellulose and holocellulose (cellulose+hemicellulose) or higher initial N concentrations. Alterations in cell-wall deposition in the bmr cultivars may increase accessibility of microbial cell-wall degrading enzymes that accelerate mass loss. Our results demonstrate that alterations in initial lignin chemistry may influence decomposition of sorghum litter in an agronomic setting.
Related Topics
Life Sciences
Agricultural and Biological Sciences
Ecology, Evolution, Behavior and Systematics
Authors
Christopher T. Ruhland, Amanda J. Remund, Celsey M. Tiry, Timothy E. Secott,