稻作環境親和栽培之環境影響評估
Journal
臺中區農業改良場特刊
Journal Issue
119
Pages
85-98
Date Issued
2013
Author(s)
Abstract
氣候與環境變遷，是現今環境生態上的重要議題。除了因人類活動產生溫室氣體所引起的全球暖化之外，優養化、酸化、水資源缺乏、能源危機等都將是未來可能遭遇的困難。面對變遷的趨勢，科學家提出的對策之一為「減輕（Mitigation）」，即調整目前產業運行方式，期望能降低現行產業造成之環境衝擊。評估環境衝擊的方式，目前常應用環境工程學之中所謂「生命周期評估（Life Cycle Assessment，LCA）」的工具，「生命周期評估」藉由調查產品從原料開採、運送、製造、加工、包裝、販售至廢棄的一連串過程之中的投入與產出，由此分析包括溫室效應潛勢（碳足跡）、優養化潛勢、酸化潛勢、水資源耗用、能源消耗等各種面向之環境衝擊。農業為人類最重要的產業，在農作物生產過程中同樣會帶來各種環境衝擊。以碳足跡為例，每生產1公斤的玉米與小麥，將分別排放0.33與0.38公斤的二氧化碳當量，然而，稻米生產的碳足跡卻是遠高於其他作物，主因在於水田的大量甲烷排放。前人研究亦顯示：農業生產過程的環境衝擊最顯著處在田間栽培階段，且可以藉由調整栽培方式，改變環境衝擊程度。例如：節水灌溉顯著降低田間碳足跡；合理化施肥可改善慣行方式的優養化與酸化衝擊；有機栽培則可以有效降低肥料製造端的能源消耗。如何平衡各項環境效益，探討一整合型的永續栽培方式，並兼顧產量及品質，發展新型的「環境親和農業」，是農業專家學者的重要目標。
Climate and environmental changes are crucial environmental and ecological issues nowadays. Greenhouse gases produced by human activities can contribute to global warming. Additionally, eutrophication, acidification, water shortages, and energy crises are potential challenges that may be encountered in the future. To face the challenges caused by climate and environmental changes, scientists have proposed a solution - ”mitigation”; that is to adjust current industrial operational models in an effort to mitigate the environmental impact from industries. Environmental engineers commonly conduct ”life cycle assessment (LCA)” that investigate the input and output of production, from the exploitation of raw materials, to the transportation, manufacturing, processing, packaging, selling, and waste of products, to evaluate the environmental impact. Life cycle assessment can evaluate various environmental impacts, including global warming potential (carbon footprint), eutrophication potential, acidification potential, water use, and energy use. Agriculture is the most essential human industry; however, the crop production process also has diverse environmental impacts. Regarding carbon footprints, 1 kg of corn and of wheat can emit 0.33 kg and 0.38 kg of CO2 equilibrium, respectively. The carbon footprint for rice is significantly higher than that of other crops and primarily results from substantial methane emissions during the field farming period. Previous studies have indicated that the most significant environmental impact of agricultural production occurs during the field farming period; however, the degree of environmental impact can be reduced by adjusting farming methods. For example, water-saving irrigation can significantly reduce the carbon footprint during the field farming period, rational fertilization can mitigate the eutrophication and acidification resulting from conventional fertilization methods, and organic farming can effectively reduce the energy used to manufacture fertilizer. How to balance various environmental benefits, establish integrative substantial farming methods that can sustain quantity and quality, and develop a new environmental-friendly agricultural industry are essential goals for agricultural experts and scholars.
Subjects
氣候變遷
水稻
碳足跡
環境衝擊
生命周期評估
有機栽培
Climate change
Rice
Carbon footprint
Environmental impact
Life cycle assessment
Organic farming
Type
journal article