Comparison among different techniques for slurry spreading: effect on the environmental performance of maize cultivation

Agriculture plays an important role on greenhouse gases emissions and most of them are caused by cattle enteric fermentation as well as by slurry management. Since in Italy, and mainly in Northern Regions, intensive livestock holdings are considerably spread, slurry management should aim to the selection of spreading techniques able to reduce ammonia and other nitrogen and phosphorous compounds emissions. In this paper, the environmental impacts of different pre-sowing fertilisation schemes for the cultivation of a maize hybrid FAO Class 700 have been evaluated using the Life Cycle Assessment (LCA) method. The evaluated fertilisation schemes differed according to a scenario with only mineral fertilisers and scenarios with both organic and mineral fertilisers. These latter included the evaluation of a superficial slurry spreading with incorporation either after 48 hours or within 2 hours and the direct slurry injection solution. Considering 1 ton of grain maize as Functional Unit (FU) and cradle-to-farm gate system boundaries, the LCA results obtained from the comparison of the scenarios were not univocal. However, the scenarios with the highest environmental benefits were the fast incorporationand the direct slurry injection. These techniques should be recommended and supported in order to benefit from a more sustainable slurry management agriculture.