N2O emissions from sugarcane production in South-central region of Brazil: Scientific basis for "carbon footprint" estimation in biofuel production

Abstract

The sugarcane activity in Brazil is rapidly expanding due to increased global demand for fuel ethanol. The objective of this proposal is to estimate N2O emissions of the sugar cane to produce ethanol using the level of detail required in Tier 2 as described by the IPCC (2006). For this, field experiments will be conducted to determine the N2O emissions in different cycles in the management of cane sugar. Experiment 1 will consist of an area of reform in which the measurements of N2O emissions will begin during the soil preparation for planting and driving to the regrowth of the harvest period. For emissions due to fertilizer nitrogen in the soil, the experiment will be conducted at 2 factorial scheme (2x2x2): two systems cover crops (with and without straw), two systems of management (with and without application of vinasse) and two nitrogen sources (urea and ammonium nitrate), plus a control treatment for each land cover and management system. Experiment 3 will consist of the application of isotopic techniques with enrichment of 15N fertilizer in order to distinguish N2O emissions from other sources of fertilizer (waste decomposition, mineralization of soil organic matter, etc.). And thus enhance the emission factor generated in Experiments 1 and 2. Experiment 4 will evaluate the spatial variability of N2O emissions with the use of geostatistics for understanding the distribution patterns of N2O in the soil. Once the information generated in this field will be integrated into the model parameterization and calibration of the TEM (Terrestrial Ecosystem Model) that will predict N2O emissions with different management scenarios in the sugar cane. This research aims to produce scientific information in order to assist in estimating the emissions of greenhouse effect gases in the production of ethanol for use as biofuel, and can serve as a basis for drawing up inventories of GHG emissions with different levels of complexity (Corporate, Regional or National) to the cultivation of cane sugar in order to produce ethanol. (AU)