Life cycle analysis of lettuce (Lactuca sativa) cultivated under an organic and conventional management system, as input for decision-making in two Costa Rican agricultural farms

Abstract

The potential environmental and economic risks of an organic and a conventional lettuce production system were evaluated and compared through a Life Cycle Analysis (LCA) and Life Cycle Cost (LCC). The kilogram of lettuce was defined as a functional unit, for a productive process with established limits between the acquisition of inputs (cradle) and transport to the commercialization (gate). Based on the findings, a multicriteria decision method known as Analytic Hierarchy Process was applied to prioritize factors of interest and the system of preference in the context under study. The main results are that the conventional system presented increased environmental impact in comparison with the organic system for indicators of global warming potential in 13%, eutrophication in 85%, acidifying gases in 62% and deterioration of the ozone layer risk in 96%. As for the LCC, the costs were higher in the organic system for the pre-production stages by 45%, production by 13% and commercialization by 32%. While in conditioning, the cost was 9,1% greater for the conventional system. It is concluded that management practices with environmental and economic potential should be oriented to aspects such as efficient use of transport, use of bio-inputs, recycling, wastewater treatment, plant waste management and participation in environmental programs and it is recommended that practices decrease focus on the stages where the greatest impacts and costs were found.