Technologies to Improve Water Management for Rice Cultivation to Cope with Climate Change

因應氣候變遷提升稻作栽培水分管理之技術

楊純明(Chwen-Ming Yang)

《作物、環境與生物資訊》 9卷3期 (2012/09) Pp. 193-207

https://doi.org/10.30061/CEB.201209.0006

摘要

為確保世界人口增長所需要的糧食供應，未來農作勢必要求能夠在全球有限水資源狀況下增加生產。很不幸的，依照現行氣候變遷情境的發展，降水型態將更加紊亂失序而無規律，極端天氣事件發生頻率也將愈來愈高，大大提升了農業灌溉淡水供給量的不確定性及農作生產效率的表現。尤有甚者，亦將因此產生區域性的缺水情況，或帶來短期的供水短缺。由於灌溉水量的不足，將使得水資源的管理更為重要，才能改進農業的水分生產效率。所幸農業灌溉用水取自於不同水源（如降雨、地表水、地下水），操作於各式農耕系統（如旱田耕作、雨灌耕作、灌溉耕作），且施用於各種需水量的農作物，因而存在多樣的、不等的改進空間。此外，亦可透過策略性灌溉規劃及耐逆境品種改良等的配合作為輔助措施，來增加農作的水分利用效率。稻米為亞太地區居民的主食之一，許多國家甚至消費其自有生產量的90％以上。作為當地最重要的糧食根源，未來將可能因為人口的增長，造成對稻米的需求超過生產幅度，但是跡象卻顯示有些高產的水稻生產區已呈現生產量停滯或下降現象。如果再加上資源趨於短蹙，農業環境逐漸惡化，則糧食供給前景堪慮。有見於此一複雜而負面的因子干擾，有識之士已著手研擬各種可能的水分管理方案，試以改進水分的利用效率及提高稻米產量，特別注重於善加利用有利的生態環境。這樣的解決方案在當前氣候快速變遷之下尤顯必要，因為氣候變遷對許多已知生產層面都會帶來不等程度的衝擊與影響，亟待因應處理。本文將據此予以突顯問題所在，使讀者瞭解其等對水稻生產力與生產量的可能影響，同時介紹針對水分管理的可行技術與措施，以更有效能的使用有限的水資源來生產稻米，並冀望能夠因而減縮因為資源與限制條件的不對等所造成的生產差異。

關鍵字

水分管理 ； 水分利用效率 ； 稻米生產 ； 氣候變遷 ； 技術

並列摘要

To ensure available food supply to meet the food requirements of the world's growing population, future crop production must be increased under the pressure of limiting global water resources. However, precipitation patterns become more erratic and frequency of extreme weather events will be increased under current climate change scenarios, thereby causing a greater uncertainty on freshwater supply for agricultural uses as well as to the performance of crop productivity. Even worse, it may give rise to regional water deficiency and/or generate water shortage in a period of time. Without sufficient water for irrigation, there is pressing need to betterment of water resource management so as to increase water productivity of agricultural sector. Fortunately, since various water resources are used, such as rainfall, surface water or groundwater, in different types of agriculture (i.e., dryland, rainfed and irrigated) to a variety of crop species, there exists wide scope and potential for the improvement. Strategic planning of water supply for demand and variety improvement for stress tolerance are also strategies that can be adopted as supplements. Rice is the staple food for the people live in the Asia and Pacific region, where nearly 90% of its production is consumed locally in most countries. As the lifeline of the people, demand for rice is expected to grow faster than production. Yet, there is signal indicating the yield deceleration and stagnation observed in some high-yield environments. The reduced resource trend and the deteriorating environment impose further threats and limits. Nevertheless, because of the complexity with incompatible changes of involved factors, different views considering available approaches of water management for improving water-use efficiency (WUE) and increasing rice production have evolved, particularly in favorable rice ecologies. In addition, climate change brings about further impacts and challenges to all aspects of rice production. This paper highlights the impacts and challenges brought by climate change that threaten to rice productivity and production, but also introduces technologies and practices that may be applied for rice culture with smart water use bridging the gap among countries/regions of unequal resources and uneven constraints by climate change.

並列關鍵字

Water management ； Water use efficiency ； Rice production ； Climate change ； Technology