熱帶氣候環境下水稻灌溉水深之研究 推動永續灌溉管理之策略

Irrigated Paddy Rice Water Depths in Tropical Climate Conditions for Promoting Sustainable Irrigation Water Management Strategy

賽維林(Aim#westeur042# S#westeur042#v#westeur042#rin Kima)

指導教授 ： 王裕民 博士

國立屏東科技大學/國際學院/熱帶農業暨國際合作系/博士(2014年)

https://doi.org/10.6346/NPUST.2014.00297

摘要

本研究調查位於撒哈拉地區的布吉納法索三個省份的陸稻產量與氣候條件應分析兩者之間的關係。布吉納法索的撒哈拉地區是受氣候影響最大，因為其典型的氣候條件與作物的低接受度，當無人推動永續灌溉管理策略經常受到資料的限制使得分析作物產量與地區性氣候關係成為困難的課題。此外，因為氣候變遷引起季節性降雨的不確定性與可用灌溉水的減少及其他需水量的增加導致水稻灌溉乾溼交替技術的發展與應用來解決水量缺少的問題。但是，當考量到季節性水源乾溼交替法是可以最佳化地使得灌溉用水的效率提升，土壤飽和水耕作方法是另一個節水的方法。實際上，這個方法的實施需要耗費更多的時間與能源。因此本研究首先試圖以多基因表示程式(GEP)及傳統的區域性時間序列迴歸來找出降雨量、溫度與陸稻產量的關係。再者以田間試驗進行尋找合適的水深減少水稻灌溉用水將4個不同水深的治療（T2CM，T3cm，T4cm和T5cm）帶大，通過有3次重複的隨機區組設計。水深從移栽至抽穗期應用週。第三，從相同的實驗研究的目的找出有效的水深可以保持土壤水分接近飽和的普遍實行灌溉間隔結合以提高水的生產力降雨模式。據統計是有影響水稻產量大幅氣候變量的組合因素。結果發現在一年到一年旱作水稻產量變化的均方差為31、37和52％是由氣溫和降水變量觀察研究區域的變化解釋。據觀察，結合溫度200毫米減少降雨的增加1℃所引起的產量減少7〜21％。實驗結果證明了GEP模型是按比例縮小（CC =0.88-97，RRSE=0.474-0.261）一個功能強大的工具表達產量反應函數（CC =0.88，RRSE=0.472，RAE=0.070）首次被遺傳編碼的氣候變量在薩赫勒，雨在屈服模型數量為70％，最重要的變量而最高溫度計算為29.3％。
研究結果顯示，一個強大的適應氣候變化的措施應該在雨水管理被削減。從實驗結果表明水分脅迫在營養生長階段減少株高和分蘗之間的7％，並在幼穗分化33％的數量，其次是完全和部分恢復增長。此外每穴穗數呈53％至180％的跌幅在抽穗期。嚴重缺水引起的最低水處理產量構成顯著減少15％，收穫52％之間。結果發現，每週應用為3cm水深加上降雨改善了全輪驅動的有效性，並取得了最高的有益用水效率與產量較少的費用。飽和度為180％的申請12.37、20.84、7.59和70.98％，分別降低株高、分蘗數、葉綠素含量和穗數每蔸。這些參數的降低跟總回收率由於有效降雨的貢獻，這導致了產量的減少6％。

關鍵字

熱帶氣候 ； 多基因 ； 局部範圍回歸 ； 乾濕交替 ； 土壤水飽和栽培 ； 水稻產量

並列摘要

This study investigated the yield response to climate variables towards the causal interdependency analysis between upland rice yield and major climatic variables in three provinces located in Sahelian region, Burkina Faso. Sahel is amongst the most vulnerable regions to weather stressors largely attributed to its typical climatic condition and low capacity to adapt. When promoting sustainable irrigation management strategy in climate change context, data limitation makes very hard to analyze crop yield responses complexity to local weather variables. Also, the uncertainty of monsoon rainfall and the decreasing availability of irrigation water, as a result of climate change, and high water demand of other sectors have resulted to wide adoption of alternate wetting and drying (AWD) technique especially in irrigated lowland rice production to overcome water scarcity. However, under climate change circumstances, AWD can be optimized when taking advantage of favorable water seasonality conditions to increase crop yield and irrigation water use efficiency. Saturated soil culture is another water saving technique that can improve water productivity. However, practically, it is either less implemented or adopted because it consumes more time and energy consuming. Therefore, this study attempts first to assess the upland rice yield response to rains and temperature factors by using multi-gene-expression programming (GEP) and a conventional local scale time series regression approaches supported by ground station data for promoting climate adaptation measures. Second, a field trial was conducted to find suitable water depth for reducing rice irrigation water use by combining four different water depth treatments (T2cm, T3cm, T4cm, and T5cm) with rainfall through a randomized complete block design having 3 replications. Water depths were applied weekly from transplanting to heading. Third, from the same experiment the study aimed to find out the effective water depth that can keep soil moisture close to saturation for a commonly practiced irrigation interval combined with rainfall pattern for increasing water productivity. Statistically, the results suggested that there is a substantial climate variables combination factors affecting rice yield. It was found that 31, 37 and 52% of the variance in year-to-year rainfed rice yield changes were explained by the changes observed in temperatures and precipitation variables in the study area. It was observed that a 1oC increase of temperature combined with 200mm decrease of rains caused yields reduction from 7 to 21%. The results attested that GEP model is a powerful tool in downscaling (CC=0.88-97, RRSE=0.474-0.261), and in expressing yields responses function (CC=0.88, RRSE=0.472, RAE=0.070) to climate variables, which is genetically coded for the first time in Sahel. Rain is the most important variable in the yield model counting for 70%, while maximum temperature counts for 29.3%. The findings suggested that a robust climate adaptation measure should be axed on rainwater management. The results from the experiment showed that water stress at vegetative stage decreased plant height and tillers number between 7 % and 33 % at panicle initiation, followed by total and partial growth recovery. In addition, panicle number per hill showed a 53 % to 180 % decrease at the heading stage. Severe water stress induced by the lowest water treatment significantly reduced yield components between 15 % and 52 % at harvest. It was found that weekly application of 3cm water depth combined with rainfall improved AWD effectiveness, and yielded the highest beneficial water productivity with less yield expenses. The application of 180% of saturation decreased plant height, tiller number, chlorophyll content, and panicle number per hill by 12.37, 20.84, 7.59, and 70.98%, respectively. The decrease of these parameters is followed by total recovery due to effective rainfall contribution; that led to low yield sacrifice (6% of reduction). Weekly application of 3 cm water depth and matching crop needed-water period with the onset of rainfall induced 40% of water saving and can be recommended as sustainable saturated soil culture practice for rice production in high water demand conditions.

並列關鍵字

tropical climate ； multi-gene ； local scale regression ； alternate wetting-drying ； saturated soil culture

參考文獻

Lee, P.P. 2011. Development trends of international agriculture. National Pingtung University of Science and Technology, Taiwan, 432 p.

Wang, Y.M., W. Namaona, S. Traore, and Z. C. Zhang. 2009a. Seasonal temperature-based models for evapotranspiration estimation under semi-arid conditions of Malawi. African Journal of Agricultural Research, 4: 878-886.

Allen, R. G., L. S. Pereira, D. Raes, and M. Smith. 1998. Crop evapotranspiration, guidelines for computing water requirements, Irrigation and drainage paper No 56, Food and Agriculture Organization of United Nations, Rome, Italy.

Almaraz, J. J., F. Mabood, X. Zhou, E. G. Gregorich, and D. L. Smith. 2008. Climate change, weather variability and corn yield at a higher latitude local: Southwestern Quebec. Climate Change 88: 187-197.

Annandale, J. G., G. S. Campbell, F. C. Olivier, and N. Z. Jovanovic. 2000. Predicting crop water uptake under full and deficit irrigation: An example using pea (Pisum stivum L. cv. Puget). Irrigation Science 19:65-72.