Simulation of Nitrous Oxide Emissions in Zoysia Turfgrass Using DAYCENT and DNDC Ecosystem Models

Nitrous oxide (N2O) is an important greenhouse gas (GHG) implicated in global climate change. Process-based ecosystem models, such as DAYCENT and DNDC, have been widely used to predict GHG fluxes agricultural systems. However, neither model has yet applied warm-season turfgrasses zoysiagrass. This study parameterized, calibrated, validated the DNDC models for N2O emissions from Meyer zoysiagrass (Zoysia japonica Steud.) using Bayes’ theorem field data Braun Bremer (2018a, 2019) Lewis (2013). Results indicated DAYCENT, but not reasonably simulated impacts of irrigation N-fertilization practices on biweekly annual zoysia turfgrass. When assuming no further change, predicted that typical recommendations (a low-input turfgrass) would reduce its cumulative warming potential (GWP) first 45 years after establishment by encouraging soil carbon sequestration. Thereafter, soils become saturated with hence, reductions N inputs be beneficial mitigating increases GWP.