ABSTRACT

Burning of sugarcane residues has been associated with several environmental and human health problems. In order to alleviate these problems and maintain sustainability of the system, sugarcane industries have started to adopt a mechanized method of harvesting that does not include burning of the residue. The objective of this study was to evaluate the impact of the conversion of burnt to unburnt sugarcane harvesting systems on soil organic carbon (SOC) stocks and soil organic matter (SOM) compartments of the northeastern region of Brazil. The study was carried out in two sugarcane mills in the state of Alagoas. In each farm, chronosequences or comparison pairs were selected, totaling seven areas (three burnt and four unburnt). The unburnt system in the conditions of the northeastern region of Brazil accumulated carbon (C) in the soil at rates similar to those found in the south-central region of Brazil (2.00 Mg C ha⁻¹ year⁻¹). Therefore, the results obtained contribute to consolidating the results of other studies and reinforce the potential of the unburnt system to promote the soil C sequestration, which is important considering the area cultivated with sugarcane. Under the qualitative point of view, the unburnt systems resulted in lower values of soil bulk density and higher values of SOC stocks, fulvic and humic acids, and also of C fractions with greater stability, which are positive indicators that this type of system is gradually improving the quality of the soils.

摘要

甘蔗残留物的燃烧与若干环境和人类健康问题有关。为了缓解这些问题并保持系统的可持续性，甘蔗行业已开始采用不包括残渣燃烧的机械化收获方法。本研究的目的是评估将燃烧的甘蔗收获系统转换为未燃烧的甘蔗收获系统对巴西东北部地区土壤有机碳 (SOC) 储量和土壤有机质 (SOM) 区室的影响。该研究是在阿拉戈斯州的两家甘蔗厂进行的。在每个农场中，选择了时间序列或比较对，总共七个区域（三个烧毁和四个未烧毁）。⁻¹年⁻¹ )。因此，获得的结果有助于巩固其他研究的结果，并加强未燃烧系统促进土壤固碳的潜力，考虑到种植甘蔗的面积，这一点很重要。从定性的角度来看，未燃烧的系统导致土壤容重值较低，SOC 储量、富里酸和腐植酸值较高，C 组分的稳定性更高，这是该类型系统逐渐发展的积极指标。改善土壤质量。