Economic and environmental sustainability analysis of guar (Cyamopsis tetragonoloba L) farming process in a Mediterranean area: two case studies

摘要

Guar (Cyamopsis tetragonoloba L.) is a spring-summer legume with a high drought tolerance, grown mainly in India, Pakistan, United States and South Africa, whose seeds contain galactomannans. These can be used as an emollient, softening or thickeningagent, a floccu-lant, as well as in hydraulic fracturing, and as a stabiliser in a wide range of other industrial activities: the production of cosmetics, paper, textiles, paints and varnishes, detergents, in construction, and in food products Qams, jellies, yogurt, mayonnaise, ketchup, diet foods, foods for coeliacs, etc.). In the light of a growing industrial demand for guar flour, in May 2012 a trial was carried out in southern Italy. Seeds from South Africa were sown in large plots on two farms withdifferent soil characteristics. The crop showed yields varying between 1.8 and 2.2 t ha~(-1). Agronomic results were then used to conduct an integrated sus-tainability analysis using the production cost analysis and the life cycle assessment, in order to assess, respectively, the cost-effectiveness and the environmental impact of the production process of guar in a Mediterranean environment. Compared to other competitive crops, guar, with less than 3000 kg of CO_2 eq. emissions, can be considered as alow-emission crop. Given the above-mentioned yield, guar growing is economically sustainable when the purchase price of seeds is not less than 0.96 6kg~(-1).