Environmental effect of improved forage fertilization practices in the beef production chain

Feeding is one of the most important factors influencing production efficiency and the environmental impact of livestock production. This study evaluates the possibility of reducing the impact of beef cattle production by optimizing the fertilization management of home-grown forage on the same farms. To this end, two scenarios were compared on two beef cattle farms in northern Italy, a baseline scenario (BS) and a scenario with optimized management (OMS) in terms of nitrogen fertilizer use. The cradle-to-gate LCA (Life Cycle Assessment) approach was used to compare the environmental performances in the different scenarios. Two different functional units (1 t dry matter of forage self-produced and 1 kg live weight of beef cattle produced) were used to express the results in relation to different stages of the supply chain. Inventory data were translated into indicators to reflect environmental pressures as well as resource scarcity by means of the ReCiPe 2016 Midpoint (H) method. The reduction of synthetic nitrogen fertilization, particularly during top fertilization, maintain yields at satisfactory levels while substantially reducing most of the evaluated impacts (e.g., Climate change from 17 % to 23 %). On the other hand, trade-offs among the different impact categories can be identified (e.g., terrestrial acidification grows up to 52 % for wheat silage). The optimization of the fertilization also involves a reduction in the impact of the feed as a whole and then of the beef cattle produced, even though the increasing number of external inputs, not affected by best fertilization practices, for each of these two phases leads to increasingly smaller reductions in impact. Ultimately, the optimization of internal crop production practices is important from an environmental point of view for farms but represents only one of the possible mitigation interventions necessary to mitigate the entire agricultural supply chain.