An Environmental Impact Assessment of Lettuce Production by Farmers Adopting Good Agricultural Practices （GAP）

Abstract

Good Agricultural Practice （GAP） measures environmental conservation and food security achievements in agricultural production. The environmental impacts of agricultural production by farmers who have introduced GAP were compared to those of conventional farmers using a lifecycle assessment based on case study scenarios. The farmers following GAP fertilized with unique method, and their lettuce cultivation global warming potential and eutrophication impacts were lower than those of conventional farmers for both open-field and greenhouse conditions. Unique fertilization techniques did not exhibit a direct relationship with environmental impact; however, an indirect relationship with global warming potential was indicated through the reduction of other inputs including pesticides and lime. The eutrophication impact was greater for conventional farmers, who tend to overfertilize with phosphorous compared to the GAP farmers, who established individual fertilization. Although heating was not employed in the greenhouses in this study, the impacts of greenhouse farming were greater than those of open-field farming. The differences are due to the production process of the greenhouse covering material.