Life Cycle Assessment of alternative water managements for rice cultivation

Italian rice production is one of the most important Italian agri-food sectors. However, cultivation of rice is one of the cultivation systems with the highest environmental impact, due to the flooding cultivation. This condition involves the degradation of organic matter in anaerobic conditions and the emission of methane that is responsible for about 40-55% of the total impact in terms of climate change. The aim of this study, that is included in BESTsomeRICE project – Development of a flooding management protocol to reduce greenhouse gas emissions in paddy fields, is to demonstrate how an alternative flooding management, characterized by an additional aeration period, can reduce methane emission and carbon footprint of Italian rice production for a greater environmental sustainability. To this purpose, a Life Cycle Assessment methodology was applied with a from cradle-to-farm gate perspective. The environmental impact of the production of two rice varieties (Carnaroli and Caravaggio) grown in 3 farms in Lomellina was analyzed. In detail, the environmental profile of two different water management systems were compared (traditional and alternative). The environmental profile was analysed in terms of 12 different impact categories: climate change (CC), ozone depletion (OD), particulate matter (PM), human toxicity – non cancer effects (HT-noc), human toxicity – cancer effects (HT-c), photochemical ozone formation (POF), terrestrial acidification (TA), terrestrial eutrophication (TE), freshwater eutrophication (FE), marine eutrophication (ME), freshwater ecotoxicity (FEx), and mineral and fossil resource depletion (MFRD). Alternative flooding management decreases emissions of CH4 in all scenarios evaluated (from 15% to 52%), resulting in a reduction in Climate Change of paddy production (from 12% to 32%). Furthermore, the alternative water management does not negatively affect grain production in terms of quantity and quality.