查詢結果分析
來源資料
頁籤選單縮合
題名 | 應用土壤水分及氮平衡耦合模式評估坡地水稻田氮汙染潛勢=Applying a Coupled Soil Water and Nitrogen Balance Model to Evaluate Nitrogen Contamination Potential of Paddy Field on Slope Land |
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作者 | 陳世楷; 張誠信; 陳昆宏; 葉峻麟; Chen, Shih-kai; Jang, Cheng-shih; Chen, Kun-hung; Yeh, Chun-lin; |
期刊 | 農業工程學報 |
出版日期 | 20120600 |
卷期 | 58:2 2012.06[民101.06] |
頁次 | 頁22-38 |
分類號 | 434.111 |
語文 | chi |
關鍵詞 | 水稻; 硝酸鹽氮; 非點源汙染; 迴歸水; Paddy rice; Nitrate-N; Non-point pollution; Return flow; |
中文摘要 | 水稻為台灣主要作物,每年期作面積達25萬公頃以上,在農業作物的化學肥料消耗量中占極大比例。水稻在種植期間多保持湛水狀態,施用化學肥料時經過氮素轉換過程,其中產生之硝酸鹽氮可藉由滲漏到達地下水或藉由降雨逕流及排水進入其他地表水體。本研究根據Chowdary et al. (2004)所發展之水田及氮平衡耦合模式,配合我國水田環境及現地監測資料進行適用性分析,模式考量水田根系土壤及湛水層之氮素轉換過程,如化肥水解、硝化、脫硝、揮發、礦化、固定、植物吸收及滲透淋洗等。模式以新竹縣新埔鎮水稻實驗田區2010年兩次期作田區排放逕流水質之硝酸鹽氮濃度進行檢定與驗證,其判定係數R2分別為0.95(二期作)及0.012(一期作),利用二期作逕流水質之硝酸鹽氮濃度可獲致極佳之檢定結果,但以一期作驗證時卻無法獲致良好結果,可能導因於兩期作在基肥施用期間,地表排水之硝酸鹽氮濃度存在極明顯之差異,一期作初期低溫造成硝化作用速率下降所致,建議模式之模擬應將溫度效應納入考量,同時利用更長期之觀測資料修正驗證此一模式。本研究利用二期作經過檢定之模式,模擬水稻田不同施肥量對周邊水體之氮污染潛勢,當施用氮肥量達200 kg/ha時,對地表逕流及地下水之汙染負荷均仍在2 kg/ha以下,遠低於揮發及脫硝作用逸失之氮量。模擬結果顯示透過適當之排水控制及肥份管理,可進一步降低水稻田施肥造成之氮汙染潛勢。本研究成果可提供作為農業非點源控制及評估農業迴歸水再利用之參考依據。 |
英文摘要 | Paddy rice is the main crop with the cultivation area about 0.25 million ha per year in Taiwan, accounts for a significant share of fertilizer consumption among agriculture crops. Losses of nitrate from applied chemical fertilizer may be high from paddy fields as they are in flooded condition for most of the cropping period. Nitrate is soluble and moves with the water percolating to groundwater or leave out by drainage or runoff. In order to evaluate the contamination potential of nitrate-N, a nitrate and water budget model developed by Chowdary et al. (2004) was adopted and revised under the environment of paddy field in Taiwan. The model includes all the important N-transformation process such as fertilizer hydrolysis, nitrification, denitrification, volatilization, mineralization, immobilization, plant uptake, and percolation that occur in both soil and pounding water in paddy field. Model calibration and validation was conducted by in-situ data of fertilizer application rate, water budget measurement and water quality analyses continued for two crop periods in Hsin-pu experimental paddy field located at Hsinchu County. Model simulation results indicate that coefficient of determination (R2) for two crop periods are 0.95 (the second crop period) and 0.012 (the first crop period), which is not well enough to meet the verification standard due to the significance difference between the first crop and the second crop on the nitrate concentration of drainage water during the early stage of basal fertilizer application. Low temperature during the early stage of the first crop may reduce the the rate of nitrification which result in the low nitrate concentration of drainage water. It is suggested that the factor of temperature should be taken into account for mode simulation, and long-term monitor on water quality is necessary to improve the effectiveness of this model. Applying the model to simulate the nitrate load from drainage water during the second crop period and assume the fertilizer application rate increase from 120 kg-N/ha to 200 kg-N/ha, the results show that both of nitrate-N loss from drainage and from percolation are smaller than 2 kg-N/ha, far below the N loss from denitrification and volatilization. It can be confirmed that fertilizer application of paddy field not the main non-point pollution source and the potential pollution load could be reduced by well drainage water control and rational fertilizer management. This research can apply a basis for non-point pollution control and assessing the re-use of agricultural return flow in paddy field. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。