PRODUCTION OF HYDROPONIC BARLEY FORAGE AND THE ENERGY FOOTPRINT OF BUFFALO MILK: RESULTS FROM A STUDY CASE

Hydroponic forage production in a controlled environment has gained attention in recent years due to the scarcity of arable land and the adverse effects of climate change on forage production. However, little is currently known about the impact of hydroponic technology on sustainable resources use by dairy farms. In this study we compare the impact of replacement of maize silage (MS) with hydroponic barley forage (HBF) on the energy footprint of buffalo milk production through a single-issue life cycle assessment. The system boundary was defined from the cradle to the farm gate, implying that direct and indirect energy inputs were quantified for all processes involved until milk left the farm gate. All inputs were referred to the functional unit of 1 kg of energy-corrected milk (ECM) produced by buffaloes fed diets based on HBF and MS. The crop energy balance highlighted that the total energy for producing 1 kg of DM from forage amounted to 1.96 and 26.97 MJ, respectively for MS and HBF. Total net energy for producing HBF was negative (-982446 MJ yr-1 ), indicating the loss of energy during the production process. Barley seed production was by far the main energy-consuming input for HBF production (81% of total energy inputs). The dietary inclusion of HBF did not alter the intake of DM (14.6 vs 14.92 kg, respectively for MS and HBF based diets) and quantity of ECM produced by cows (20.4 vs 21.7 kg). However, replacing MS with HBF raised the energy embedded into the daily ration from 45.1 to 138.9 MJ, resulting in an additional energy cost of 3.9 MJ per kg of ECM produced. Based on these results, the analyzed HBF production cannot be considered an environmentally friendly alternative to conventional maize silage production