The agricultural intensification through sugarcane cultivation is associated with the deterioration of aquatic ecosystems and riparian forests. Among its main impacts, the fertilization procedure draw attention because can cause eutrophication of aquatic ecosystems and generate greenhouse gases. Therefore, the aim of this study is to evaluate the potential of riparian forests in capture and transform the nitrogen from the sugarcane crops for bioenergy production and to estimate the greenhouse gas emission in these environments. One of the final destinies of the nitrogen that hasn't been processed by riparian vegetation are the streams. Therefore, it will be evaluated the role of nitrogen and other nutrients and environmental conditions in the denitrification and greenhouse gas emission from streams. For this purpose, 3 streams and riparian forests draining sugarcane crops and 3 streams and riparian forests draining preserved areas will be sampled and submitted to experiments of denitrification and greenhouse gas emissions. We will follow the push-pull method with 15N for the denitrification estimation in riparian forests and the open-channel method for the estimation of denitrification and carbon dioxide and methane emissions in the streams. Nitrous oxide emissions in riparian forests will be correlated with the soil physical and chemical characteristics and with the abundance of microbial functional genes (nirK/S, norB/C and nosZ), which codifies essential enzymes in the denitrification process. Nitrous oxide, carbon dioxide and methane emissions in streams will be related with physical and chemical characteristics of stream water. From these results, it will be possible to analyze which are the main variables that stimulates the denitrification and greenhouse gas emissions in tropical riparian buffers and streams.
News published in Agência FAPESP Newsletter about the scholarship: