台灣水田、旱田與濕地土壤氧化亞氮之釋放通量及其減量對策

Estimation and Mitigation Strategies of Nitrous Oxide Emissions from Paddy, Upland Field and Wetland Soils in Taiwan

錢元晧(Yuan-Hao Chien) ； 賴朝明(Chao-Ming Lai) ； 楊盛行(Shang-Shyng Yang)

《土壤與環境》 13卷1&2期 (2010/12) Pp. 23-42

https://doi.org/10.30058/SE.201012.0002

摘要

本研究選擇台灣兩處水稻田、十三處旱田與一處濕地，以密閉罩法於田間或現地實測一年其土壤氧化亞氮之釋出通量，並估計民國九十年台灣農田土壤釋出氧化亞氮之總量，再與IPCC （Intergovernmental Panel on Climate Change，政府間氣候變遷委員會）方法之估計結果進行比較；另同時量測其環境影響因子與分析土壤性質，再以SAS統計軟體進行簡單相關分析與逐步迴歸分析，並據以提出其減量對策。結果顯示：水稻田、旱田及濕地之全年釋放量分別估計為3.15~5.23、3.65~121、5.53kgN2O ha^（-1） yr^（-1）。據以估計民國九十年台灣水稻田、旱田及濕地土壤釋出氧化亞氮之總量分別為696、8,117、63 ton N2O。進一步以IPCC方法估計民國九十年台灣農業土壤釋出氧化亞氮之總量為18.4 Gg N2O，高於本研究實測估計之8.8 Gg N2O。環境影響因子與土壤氧化亞氮釋出通量之統計分析結果顯示：簡單相關分析與土壤氧化亞氮之釋放通量顯著相關者，水稻田為氣溫、全氮與銨態氮，旱田為pH、水分充滿孔隙率、有機質含量、全氮、銨態氮與比導電度，濕地則為氣溫與土溫。逐步迴歸分析對土壤氧化亞氮之釋放通量顯著貢獻者，水稻田依序為氣溫、pH、硝酸態氮含量，旱田依序為pH、水分充滿孔隙率、無機態氮含量、全氮，濕地則為土溫。根據本研究結果進一步提出台灣農田土壤氧化亞氮釋出之減量對策為：注意不宜施用過量氮肥與注意旱田不宜灌溉過量。

關鍵字

氧化亞氮 ； 水稻田 ； 旱田 ； 濕地 ； 土壤 ； 釋出 ； 減量對策

並列摘要

Two paddy, thirteen upland, and one wetland soils in Taiwan were selected to estimate the nitrous oxide fluxes by a closed chamber method. The results were further used to estimate the total N2O emission amounts of paddy, upland field, and wetland soils of Taiwan in 2001, which were then compared with those by the IPCC (Intergovernmental Panel on Climate Change) method. The environmental affecting factors and selected soil properties were also measured and used to examine their relationships with the nitrous oxide emission by simple correlation analysis and stepwise regression analysis. The results were also used to suggest the mitigation strategies of nitrous oxide emissions from the paddy and upland field soils in Taiwan.The results showed that yearly N2O emissions from paddy, upland field, and wetland soils were estimated to be 3.15 ~ 5.23, 3.65 ~ 121, and 5.53 kg N2O ha^(-1) yr^(-1), respectively. The total estimated N2O emission amounts of paddy, upland, and wetland soils of Taiwan in 2001 were 696, 8,117, and 63 ton N2O yr^(-1), respectively. The estimated nitrous oxide emissions from agriculture soils of Taiwan in 2001 by the IPCC method (18.4 Gg N2O yr^(-1)) were higher than those obtained by the closed chamber method (8.8 Gg N2O yr^(-1)) in this study. The results of simple correlation analysis showed that the significant correlation affecting factors were air temperature, total nitrogen content, and ammonium content for paddy soils; pH, water filled pore space, organic matter content, total nitrogen content, ammonium content, and electrical conductivity for upland soils; air temperature and soil temperature for wetland soil. The results of stepwise regression analysis showed that the significant contributing factors to nitrous oxide fluxes were: air temperature, pH, and nitrate nitrogen content for paddy field soils in a decreasing order; pH, water filled pore space, inorganic nitrogen content, and total nitrogen content for upland field soils in a decreasing order; and soil temperature for wetland soil. The results further suggested that the mitigation strategies of nitrous oxide emissions from paddy and upland field soils in Taiwan were ”don't apply too much nitrogen fertilizer to both soils” and ”don't irrigate too much water for the upland field soil”.

並列關鍵字

Nitrous oxide ； Paddy field ； Upland field ； Wetland ； Soil ； Emission ； Mitigation strategy