Assessing potential desertification environmental impact in life cycle assessment. Part 2: agricultural case study in Spain and Argentina

Abstract

Purpose: Land use in dry lands can result in a final stage where land is completely depleted or entirely degraded causing the desertification phenomenon. The first part (part 1) of this series of two articles proposed a methodology to include desertification in life cycle assessment (LCA). A set of variables to be measured in the life cycle inventory, characterization factors, and an impact assessment method for the life cycle impact assessment phase were proposed. This second part (part 2) aims at showing the application of the model proposed in part 1 on two case studies of agricultural activities. Methods: The impact model proposed is applied to plots of land devoted to agricultural activities in two countries: Argentina and Spain. In the agricultural plots of Spain (1SP to 9SP), two crops were analyzed: winter wheat (Triticum aestivum) and rapeseed (RS, Brassica napus). Two crops were considered in the Argentinean case study: rapeseed (RS, B. napus) and digit grass (Digitaria eriantha) (10AR to 17AR). A bare soil state is considered in both countries as a reference state. Both case studies consider only the agricultural stage in the inventory of a complete life cycle assessment study. Both also consider only one impact category in life cycle environmental assessment: desertification impact due to land occupation. Results and discussion: On the basis of the obtained results, it can be inferred that cultivating 1 ha of rapeseed and 1 ha of wheat has the same impact on the analyzed plots in Spain and improves the reference state conditions in 50 % of the cases. Moreover, rapeseed grown in Mendoza produces almost the same impact as in some of the Spanish plots. Normalized areas of plots could be useful to compare results in different regions of the world to avoid the influence of the area of occupation in results. Conclusions: The proposed model implies a contribution of significant importance because so far there has not been an impact assessment tool for land use in dry lands within the LCA framework. The main strength of the proposed model is that it allows a simple way to quantify the desertification impact. Also, it is emphasized that the model can be adapted virtually without difficulty to the evaluation of all types of crops with different management practices in different regions in the life cycle impact assessment stage.