Combining cleaner production and life cycle assessment for reducing the environmental impacts of irrigated carrot production in Brazilian semi-arid region

Abstract

Agriculture is the activity that contributes most to the emission of greenhouse gases, water quality degradation, soil loss and nutrient runoff worldwide. These harmful environmental impacts are issues in irrigated agriculture in the Brazilian semi-arid region. The rational use of natural resources and the efficiency of agricultural systems can reduce the environmental impacts and are essential for a more sustainable agriculture. However, a limited amount of data concerning the environmental impacts of horticultural practices is available. To date, no evaluation of a carrot crop life cycle in Brazil could be found in the literature. The purpose of this paper is to present a methodological approach combining Life Cycle Assessment (LCA) and Cleaner Production (CP) principles in the environmental and economic evaluation of irrigated carrot farming. Life Cycle Impact Assessment was carried using the International Reference Life Cycle Data System (ILCD, 2011) method, including data uncertainty. We evaluated the base scenario based on management practices widely adopted in the studied area, and the recommended scenario based on adoption of CP selected opportunities using agronomic recommendations for the carrot production system. By these means, the environmental impacts can be reduced between 15 and 70% in the evaluated categories from the base to the recommended scenario. Most environmental impacts were related to fertilizer production and field emissions. The global warming effect related to the emission of 0.12 kg CO2 eq/kg product from the base scenario can be reduced to 0.07 kg CO2 eq/kg product in the recommended scenario. This represents a lower value than most global warming rates for carrots found in literature. The costs of inputs were reduced by 49% from in the recommended scenario. Most costs of inputs were related to fertilizers and seed purchasing. The combined use of the two methods proved feasible as LCA identifies the main hotspots of the analyzed system, while CP support practices that reduce costs and the use of inputs such as water, energy, fertilizers, seeds and pesticides. CP provided a higher level of compliance with the technical requirements for the studied system and proved to be more economically and environmentally efficient than ‘end of pipe’ practices. The complementary use of CP and LCA provided better support for a more sustainable irrigated carrot production in the semiarid region of Brazil.