Comparison between organic and conventional farming systems using Life Cycle Assessment (LCA): A case study with an ancient wheat variety

Abstract

Assessing the environmental impact of agriculture is a key factor towards reducing human impacts on the food production chain. Because of the growing consumer interest in healthy foods cultivated with low-impact approach, a study assessing the impacts of ancient wheat variety in organic and conventional farming appears to be of great importance. Thus, this study was aimed at assessing and comparing the environmental impacts and resources consumptions of organic and conventional farming practices on an ancient soft wheat variety (var. Verna) in Tuscany, Italy. The fact that Verna wheat falls within the PDO bread specification, one of the few at the European level, increases the importance of this work. A cradle-to-grave life cycle assessment (LCA) from raw material extraction, through to industrial processing, field utilization, grain harvesting and finally transportation to storage centres was carried out. This study analysed data sampled over a five-year period (2014/2015 to 2018/2019) derived from five organic and conventional farms, respectively. The impact categories considered included: global warming, freshwater ecotoxicity, seawater ecotoxicity, terrestrial ecotoxicity, human toxicity, acidification, eutrophication, photo-oxidant formation, non-renewable energy resource consumption, renewable energy resource consumption, water consumption and land use. In almost all the impact categories, organic farming was shown to have lower environmental impacts, while conventional farming had a lower impact on land use. Results relating to acidification, photo-oxidant formation, ozone layer depletion and non-renewable energy resource consumption were considered similar for the two cultivation systems. Normalization of the results showed that seawater ecotoxicity had the greatest impact among all impact categories (> 99%) for both cultivation systems. Moreover, major environmental problems in conventional farming and organic farming were the use of synthetic N fertilizers and low yields, respectively. Results showed that 192 ×106 hectares of organic farming would be needed to maintain current wheat production in the EU, compared to just 99 ×106 hectares cultivated with the conventional farming. Accordingly, yield increase in organic farming, and reduction of nutrient losses/emissions from conventional farming, are the two most promising strategies towards maintaining a high agricultural production with concomitant reductions in the related environmental impact.