Diego Oliveira Ribeiro
Abstract:
The conversion of natural ecosystems to agricultural activity results in an initial entropy of the system affecting the dynamics of soil organic matter, and studies on the impacts of agricultural activity are required. Aimed to evaluate the impact of conversion of native coval areas to no-till agricultural activity on soil organic matter and its fractions. The study was carried out in areas belonging to Fazenda Boa Vista, in Haplossol, submitted to a 7, 11 and 16-year chronosequence, managed under no-tillage system, and a reference area characterized by the top and bottom of the murundus. Total organic carbon stocks were similar, the top native area (45.9 Mg ha-1), with 7 years (38.8 Mg ha-1) of no-tillage implementation, with a higher upward trend with increasing of this management system. However, when compared to the murundus base (58.9 Mg ha-1) there is a reduction in carbon stocks due to the different humidity conditions of the murundus agricultural systems and top. The C-MOP fraction recovered stocks with only 7 years of PD. The weighted average diameter of the aggregates followed the soil organic matter stocks, presenting 2; 2.1; 2.4; 2.4; and 2.8 mm for treatments PD7, PD11 PD16 CT and CB. No-tillage equalized carbon stocks at the top native area with 7 years of its driving increasing the quality of organic matter tending to increase with longer driving time.
