Introducing lupin in autochthonous wheat rotation systems in Galicia (NW Spain): An environmental and economic assessment.

Abstract

Crop diversification, as a sustainable land management practice, is a potential strategy to face soil degradation, climate change and food security, being the incorporation of legumes in cereal rotation systems, a strategy that improves soil nutrient levels. In a context of sustainable agriculture, this manuscript aims to evaluate the effect of lupin cultivation from an environmental and economic perspective in Galician winter wheat-based rotation systems. The life cycle analysis (LCA) methodology was applied for three rotation systems over a six-year period: lupin + wheat + oilseed rape (RA1), lupin + potato + wheat (RA2), and lupin + wheat + oilseed rape + maize (RA3). The general approach of this study was to collect primary data associated with the rotation crops to quantify their environmental impacts and economic benefits and to identify their advantages or disadvantages. Comparing and contrasting the environmental profiles based on three functional units: hectare land (ha), financial indicator (gross margin, €) and yield production (kg of wheat grain) allows a robust evaluation of each crop rotation system. Relating to rotations without lupin, the results indicate that for the impact categories evaluated, the introduction of lupin proved to be favourable with notable reductions of 64% and 30% in the environmental categories of Global Warming and Marine Eutrophication, respectively. Moreover, favourable economic consequences were evident in rotations RA1 and RA2 with a 19% and 51% increase in financial indicators, respectively, but with a marginal reduction of 2% in gross margin in RA3. This study motivates stakeholders to understand the environmental impacts of diversification strategies in agricultural systems and serves as a baseline to address the assessment of the social aspects of these systems for a complete sustainability perspective.