Fertilizer type influences tomato yield and soil N2O emissions

Improvements in crop management for a more sustainable agriculture is fundamental to reduce environmental impact of cropland and mitigate effects on global climate change. In this study three fertilization types - ammonium nitrate (control), mineral fertilizer added with a nitrification inhibitor (DMPP), and an organo-mineral fertilizer (OM) - were tested on a tomato crop in order to evaluate effects both on crop production and soil N2O emissions. Plants grown under OM fertilization had a greater relative growth rate (RGR) compared to mineral fertilization, due to an higher net assimilation rate (NAR), which was related to greater light interception rather that to a higher photosynthetic efficiency. OM fertilization determined the highest fruit production and lower soil N2O fluxes compared to NH4NO3, although the lowest soil N2O fluxes were found in response to mineral fertilizer added with a nitrification inhibitor. It can be concluded that organo-mineral fertilizer is a better nutrient source compare to mineral fertilizers able to improve crop yield and to mitigate soil N2O emission.