Combining reference trials, farm surveys and mathematical models to assess carbon footprint and mitigation measures in tropical agriculture

This study aimed at estimating carbon footprint (CF) and assessing mitigation options for selected tropical crops using excel-based models, parameterized with data collected through closed-ended questions questionnaires, combined with a reference trial (RT). Most of the estimates using structured interviews were similar to those measured in the RT and the literature. Total average emission intensities ranged from 24 to 290 kg CO2eq·Mg−1, where the extreme values corresponded to cassava in the RT (24 kg CO2eq·Mg−1) and maize in interviewed farmers in Barranca province (290 kg CO2eq·Mg−1). Overall, fertilizer production and application contributed to 77% of total greenhouse gas (GHG). Transportation generated emissions comparable to field estimates. Farm emissions can be reduced in 17 to 27% with incorporation of mitigation practices. The methodology used in this study constitute a useful and easily applicable tool to assess ex-ante the impact of policies and decisions on CF under farm conditions. It can also be used by different stakeholders for different purposes; including but not limited to: label products offered in the market with GHG emission estimates, make decisions to regulate the emissions in the agricultural sector, and to enable farmers to negotiate prices and incentives for environmental preservation with quantitative information.