Organic versus conventional citrus. Impact assessment and variability analysis in the Comunitat Valenciana (Spain)

Abstract

[EN] Purpose Taking into account the large area of citrus in Spain and the impacts generated by agriculture, reducing the environmental impact of this crop represents an important goal. This study attempts to compare the environmental impact of two citrus cropping systems, organic and conventional, in the region of Valencia (Spain), and to assess the variability within both farming systems in order to highlight the influence of management practices on the environmental performance. Methods A survey was carried out on citrus farmers, 145 corresponding to organic production and 122 to conventional. Life cycle assessment (LCA) was used to estimate the environmental impacts of farms and the contribution of each production stage to impacts. Two functional units (FUs), massand area-based, were chosen. The variability and confidence intervals of the average impact results were assessed by means of a bootstrap technique. Finally, a k-means cluster analysis was performed to identify groups of farms with comparable impact levels . Results and discussion The mean impact values of the conventional farm sample were higher than those of the organic farms, when using 1 ha year−1 as FU, whereas for the FU of 1 kg no differences were found for some impact categories. Most of the impact results were also observed to be highly variable. The distribution of the mean after the bootstrap confirmed both the variability of the impacts and the differences between the farming systems. The cluster analysis determined two groups via their impact categories. Cluster-1, which showed higher impacts, was made up of part of the conventional farms while cluster-2 included the remaining conventional farms and all the organic ones. No difference in yield was found between the conventional farms of both clusters. Conclusions Bootstrapped LCA offers the ability to assess the variability of the impacts, regardless of the sample size and the non-normal impact distributions. The cluster analysis shows that conventional farms can attain similar impacts than the organic ones, while maintaining the yield. FU selection is crucial, since a mass-based FU reduces the difference in the environmental performance between conventional and organic farms. To attain a more sustainable citrus farming, a careful selection of the management practices is needed