Greenhouse gas emissions and soil C and N under organic and conventional sugarcane cultivation

Abstract

In the last years, the increasing demand in home and outside market for quality, safety and sustainability of sugar production has caused changes, reflecting significantly in Brazilian production. Motivated by market expansion, sugarcane producers are converting conventional productions areas into organic. It is known that the organic sugarcane production promotes improvements in soil structure and modifies chemical, physical and biological attributes of soil dynamics. However, there isn't enough information about this system contribution for C and N soil sequestration and greenhouse gases emissions due to organic wastes application. This research aims to estimate the GHG emissions dur to the application of residues in areas under organic sugarcane production and compare C and N soil sequestration by this two production systems. Therefore, the following situations has to be investigated: sugarcane area under conventional cultivation and another one under organic cultivation. As a reference, an area under native vegetation should be potentially used. C and N soil sequestration will be quantified by the dry method using LECO CN-2000. Changes in chemical (macro and micronutrients, CEC, BS, pH, Al+3) and physical soil properties will be determined. Furthermore, soil organic matter (SOM) quality will be evaluated by chemical and physical fractioning and humic substances characterization. C origin in this areas will be identified using 13C natural abundance.