Dissertations and Theses

Summary

Strategies for reducing greenhouse gas (GHG) emissions in agriculture have been discussed for some time, especially in Brazil, where agricultural soils contribute with 9.3% of national emissions. The objective of this work was to estimate the GHG emissions from the sources of emissions from the agricultural sector and mobile combustion in the conversion of the systems for the harvesting of burnt manual cane (mechanized cane) and compare it with the results obtained from the field evaluations of C-CO2 emissions induced by soil preparation, liming and application of agricultural gypsum, presenting possible mitigation strategies. The results indicated that the synthetic nitrogen fertilization and the burning of residues are responsible for the higher emissions observed in areas of raw and burned cane, with 1,167.6 and 941.0 kg CO2eq ha^-1ano^-1, respectively. The areas of cane burned presented the highest emissions with 3,103.9 kg CO2eq ha-1ano-1. Estimates indicated that the conversion of burned sugar cane to areas of raw cane can reduce emissions by 310.7 kg CO2eq ha^-1ano^-1 (without considering soil carbon sequestration) and 1,484.0 kg CO2eq ha-1ano-1 (considering soil carbon sequestration). The C-CO2 emissions related to the reform of the raw cane area with the usual management practices considered resulted in 1,103.8 kg C-CO2ha-1 in 25 days, as well as the simple removal of the straw from the soil surface resulted in additional emissions of 252.4 kg of C-CO2ha-1 or 925.3 kg CO2. The development of sugarcane production in Brazil should certainly be aimed at reducing the practice of burning waste and the use of diesel, reducing some soil preparation operations and also adopt more efficient fertilization practices to reduce the use of N fertilizers, obtaining reductions of greenhouse gas emissions from the agricultural sector of sugarcane.