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Nitrous oxide emissions and nitrogen cycling in managed grassland in Southern Hokkaido, Japan
Title: | Nitrous oxide emissions and nitrogen cycling in managed grassland in Southern Hokkaido, Japan |
Authors: | Shimizu, Mariko Browse this author | Marutani, Satoru Browse this author | Desyatkin, Alexey R. Browse this author | Jin, Tao Browse this author | Nakano, Kunihiko Browse this author | Hata, Hiroshi Browse this author | Hatano, Ryusuke Browse this author |
Keywords: | grassland | gross mineralization | manure | nitrogen surplus | nitrous oxide |
Issue Date: | Aug-2010 |
Publisher: | Blackwell Publishing |
Journal Title: | Soil Science & Plant Nutrition |
Volume: | 56 |
Issue: | 4 |
Start Page: | 676 |
End Page: | 688 |
Publisher DOI: | 10.1111/j.1747-0765.2010.00496.x |
Abstract: | Nitrous oxide (N2O) emissions were measured and nitrogen (N) budgets were estimated for two years in the fertilizer, manure, control and bare plots established in a reed canary grass (Phalaris arundinacea L.) grassland in Southern Hokkaido, Japan. In the manure plot, beef cattle manure with bark was applied at a rate of 43-44 Mg fresh matter (236-310 kg N) ha^[-1] year^[-1], and a supplement of chemical fertilizer was also added to equalize the application rate of mineral N to that in the fertilizer plots (164-184 kg N ha^[-1] year^[-1]). Grass was harvested twice per year. The total mineral N supply was estimated as the sum of the N deposition, chemical fertilizer application and gross mineralization of manure (GMm), soil (GMs), and root-litter (GMl). GMm, GMs and GMl were estimated by dividing the carbon dioxide production derived from the decomposition of soil organic matter, root-litter and manure by each C : N ratio (11.1 for soil, 15.5 for root-litter and 23.5 for manure). The N uptake in aboveground biomass for each growing season was equivalent to or greater than the external mineral N supply, which is composed of N deposition, chemical fertilizer application and GMm. However, there was a positive correlation between the N uptake in aboveground biomass and the total mineral N supply. It was assumed that 58% of the total mineral N supply was taken up by the grass. The N supply rates from soil and root-litter were estimated to be 331-384 kg N ha^[-1] year^[-1] and 94-165 kg N ha^[-1] year^[-1], respectively. These results indicated that the GMs and GMl also were significant inputs in the grassland N budget. The cumulative N2O flux for each season showed a significant positive correlation with mineral N surplus, which was calculated as the difference between the total mineral N supply and N uptake in aboveground biomass. The emission factor of N2O to mineral N surplus was estimated to be 1.2%. Furthermore, multiple regression analysis suggested that the N2O emission factor increased with an increase in precipitation. Consequently, soil and root-litter as well as chemical fertilizer and manure were found to be major sources of mineral N supply in the grassland, and an optimum balance between mineral N supply and N uptake is required for reducing N2O emission. |
Rights: | The definitive version is available at www.blackwellsynergy.com |
Type: | article (author version) |
URI: | http://hdl.handle.net/2115/46870 |
Appears in Collections: | 農学院・農学研究院 (Graduate School of Agriculture / Faculty of Agriculture) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 波多野 隆介
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