查詢結果分析
來源資料
頁籤選單縮合
題 名 | 水田之N[feaf]O釋放:無機氮肥與水稻品種之效應=The N[feaf]O Emission from Paddy Soil: Effects of Inorganic Nitrogen Fertilizers and Rice Varieties |
---|---|
作 者 | 趙震慶; | 書刊名 | 中華農學會報 |
卷 期 | 174 1996.06[民85.06] |
頁 次 | 頁111-133 |
分類號 | 434.111 |
關鍵詞 | 水稻; 無機氮肥; 氧化亞氮; 根圈; 微生物; 土壤; Paddy soil; Nitrous oxide; Rhizosphere; Inorganic nitrogen fertilizer; Rice; Microorganism; |
語 文 | 中文(Chinese) |
中文摘要 | 氧化亞氮(N₂O)為土壤釋放微量氣體之一,具有溫室效應與破壞臭氧之潛能。降低N₂O生長量為目前重要研究課題。水稻為重要糧食作物,而水田亦證實可釋放於N₂O。本研究採和興系粘質壤土為盆栽與田間試地用土,以密閉室法測不同種類氮肥與兩種施氮量及六個水稻品種於生長期中N₂O淨釋放量之變化。另剪除稻株不同部位,希證明稻株是N₂O由土壤向大氣傳輸之途徑。再比較抽穗期根圈土壤中與N₂O生成相關微生物族群數,酵素活性及化學成分,企能找出調控N₂O生成之因子。 N₂O釋放量因施用化學氮肥而快速上昇隨後漸漸下降,於二期稻作83天生長期中,六個水稻品種釋放N₂O-N之累計量為施氮量之0.8-8.4%,香糯釋放量較低,臺中190號粳稻與臺農秈20號較高,所用三種氮肥中以硝酸鈉釋放量最多,硫酸銨最少,而尿素居中。氮肥施用量增加,水稻盆栽土壤釋放N₂O量亦增加,氮肥用量之效應高於水稻品種間之差異。於一期稻作74天生長期中,二種施用量的尿素,硫酸銨及氯化銨等三種氮肥,釋放N₂O-N之累計量為施氮量之0.39至1.50%,仍以香糯與施用硫酸銨之處理,N₂O累計釋放量低於臺中189號粳稻與臺中秈17號兩水稻品種與所用三種氮肥之各處理。田間觀測水稻品種與肥料種類對N₂O釋放量之趨勢與盆栽相同。於一期作102天生長期中,每公頃施氮量為120 kg時,施用硫酸銨所釋放N₂O-N累計量每公頃為1.27至1.76 kg,而尿素為1.70至2.32 kg,視水稻品種而異。挖除莖基或將莖部剪除至水面下之處理,N₂O釋放量明顯較莖部保持在水面上或全株的處理為低,顯示根圈中生成的N₂O可經由稻株向大氣移動。盆栽與田間根圈土壤的短期硝化活性高於非根圈土,而脫氮活性適相反,並顯示氧化亞氮還原酵素活性潛勢可能為調控N₂O生成主因之一。綜合前述,水田N₂O係由硝化與脫氮作用共同生成,淨釋放量因氮肥種類、施用量及水稻品質而異,稻株為根圈土壤N₂O進入大氣主要途徑之一。 |
英文摘要 | Nitrous oxide (N₂O), one of the important trace gases produced in and emited form soil, is charged contributing to global warming and ozone (O₃) layer depleting. Decreasing N₂O production and emission are the important current research topics. Rice is an important food crop for world's population, however, paddy soil as recognized as a place of N₂O emission. In this study, Hohsing clay loam was used in pot culture and field trial, to see the effect of various nitrogen sources and rice varieties on the N₂O emission during growth period. Partial parts of rice plant were cut to confirm the rice plant is a conduit for N₂O transportation from soil to atmosphere. During the experiments, comparisons were also made among microbial population, activities and chemic al components in rhizosphere soil of various rice varieties at heading stage, which was related to N₂O formation, in the hope of finding the main factors regulating N₂O emission from paddy soil. Results showed that, the rates of N₂O emission from pot culture were increasing with the day receiving of nitrogen fertilizers, and decreased after then. During 84 days of rice growth period in second crop, the total amount of N₂O-N emission from pot culture of six rice varieties was 0.8 to 8.4% of total amounts of nitrogen fertilizer application. Among the varities, the Aroma was the lowest, while Taichung 190 and Tainung Sen 20 the highest. Sodium nitrate was higher than ammonium sulfate, while urea was in intermediate. N₂O emission from paddy soil was increasing with amounts of nitrogen fertilizer application. The effect of nitrogen fertilizers application on N₂O emission was higher than that from rice varieties. During 74 days of rice growth period in first crop of pot experiment, the total amount of N₂O emission from soil were from 0.39 to 1.50% of the total amounts of various nitrogen sources and rates application. Variety Aroma and ammonium sulfate application had lower N₂O emission than the other rice varieties and N-sources. Same results were found in the field as pot culture. During 102 days of rice growth period under the nitrogen fertilizers 120 kg N ha⁻¹ application, the total mounts of N₂O-N emission from field soil were 1.27 to 1.76 kg ha⁻¹ in ammonium sulfate plot and 1.70 to 2.32 kg ha⁻¹ in urea plot. The N₂O emission from pot soil of treatment of rice plant s cut whole culm or cut culm below water level was lower than that from pot soil of treatment of intact plants or plants cut culm above water level, which indirectly confirmed the N₂O produced in rhizosphere and translocated to atmosphere was through rice plant. The activity of nitrification of rhizosphere soil was higher than that in non-rhizosphere soil, and of denitrification in rhizosphere was lower than that in non-rhizosphere soil. The nitrous oxide reductase activity potential was one of main factors to regulate N₂O emission from paddy soil. Based on these figures, this study shows that nitrification and denitrification contributed primarily to the N₂O formation in paddy soil. The magnitude of N₂O evolution rates was dependent on the nitrogen type and amount of nitrogen fertilizer and rice varieties used. And rice plant was one of main ways of translocating N₂O from paddy soil to atmosphere. |
本系統中英文摘要資訊取自各篇刊載內容。