環境こだわり農業における温室効果ガス排出のLCA 評価

―水稲栽培を対象として―

抄録

The standards vis-à-vis environmentally friendly agriculture practices in Shiga prefecture include r eductions in the frequency of synthetic pesticide application and in chemical nitrogen fertilizers inputs to less than 50% of the levels seen in conventional agriculture. This study examines whether envir onmentally friendly rice production practices help mitigate global warming; it does so by using the life cycle assessment method. Organic fertilizers used in environmentally friendly rice production caused a large increase in methane emissions from paddy fields; consequently, environmentally friendly rice production practices actually increased total greenhouse gas emissions, compared to conventional production practices. Our results suggest that efforts to control methane emissions—such as midseason drainage prolongation—should be included in standards vis-à-vis environmentally friendly rice production, in order to reduce greenhouse gas emissions.