Application of DNDC Model to Estimate $N_2O$ Emissions from Green Tea Fields in Japan

• Published in: Journal of crop science and biotechnology Vol. 14; no. 2; pp. 157 - 162
• Main Authors: Kwack, Yurina, Kobayashi, Kazuhiko
• Format: Journal Article
• Language: Korean
• Published: 2011
• Subjects: tea; N fertilization; Japan; DNDC; N_2O
• ISSN: 1975-9479

Heavy doses of N fertilizers are commonly applied to green tea fields in Japan, and cause large amount of nitrate leaching in ground water and emission of ammonia and nitrous oxide ($N_2O$) to the atmosphere. The Denitrification and Decomposition (DNDC) model was tested against experimental data on $N_2O$ emissions from the tea field in Nishio, Aichi, Japan. There were reasonable agreements between the simulated and measured values of $N_2O$ emissions for this site. The model was then applied for estimating the environmental impacts as affected by farm management practices, climate change, and soil properties. The model results were assessed with respect to major indicators of agro-ecosystems including crop yield, soil organic carbon sequestration, nitrate leaching loss, and $N_2O$ emission. The results indicated that use of compost significantly reduced nitrate leaching and $N_2O$ emissions in comparison with N fertilizer. When soil pH and texture shifted to non-acidic and coarser soil, $N_2O$ emission increased; and a change in temperature and precipitation affected $N_2O$ emission, nitrate leaching, and SOC sequestration. This study thus revealed the biogeochemistry model as a powerful tool in addressing the complex efficacy of the alternative farm management practices in tea fields across various climate and soil conditions.