Physical Sciences and Mathematics Commons^™

Soil Extracellular Oxidases Mediated Nitrogen Fertilization Effects On Soil Organic Carbon Sequestration In Bioenergy Croplands, Jianjun Duan, Min Yuan, Siyang Jian, Lahiru Gamage, Madhav Parajuli, Kudjo E. Dzantor, Dafeng Hui, Philip A. Fay, Jianwei Li

Agricultural and Environmental Sciences Faculty Research

Nitrogen (N) fertilization significantly affects soil extracellular oxidases, agents responsible for decomposition of slow turnover and recalcitrant soil organic carbon (SOC; e.g., lignin), and consequently influences soil carbon sequestration capacity. However, it remains unclear how soil oxidases mediate SOC sequestration under N fertilization, and whether these effects co-vary with plant type (e.g., bioenergy crop species). Using a spatially explicit design and intensive soil sampling strategy under three fertilization treatments in switchgrass (SG: Panicum virgatum L.) and gamagrass (GG: Tripsacum dactyloides L.) croplands, we quantified the activities of polyphenolic oxidase (PHO), peroxidase (PER), and their sum associated with recalcitrant C acquisition …