FRAÇÕES GRANULOMÉTRICAS E OXIDÁVEIS DA MATÉRIA ORGÂNICA EM SISTEMAS DE COLHEITA DE CANA - DE - AÇÚCAR

Abstract

The systems of harvesting sugar cane can cause changes in fertility, quantity and quality of organic matter and the degree of oxidation, altering soil carbon stocks. Given this context, the objective was to evaluate the production of dry biomass (DB), soil fertility, the content of total organic carbon (TOC), the car- bon in particle size fractions (particulate organic carbon (COp) and organic carbon associated with minerals (COam)) and oxidizable organic matter fractions (F1, F2, F3, F4 and F1 / F4) in manual harvesting (CMa) and mechanized (CMe) of sugar cane. The sampling for biomass production was conducted in area of 1 m 2 at four points per plot, soil samples were collected at depths of 0.00 - 0.05; 0.05 - 0.10; 0.10 - 0.20 and 0.20 - 0.40 m. The average annual production of dry biomass in the area CMe was 17 times higher when compared to the area of CMa; The pH and phosphorus content was significantly lower in the larger depths area CMa when compared with that of Cme; the harvesting system caused significant CMe in TOC, COp and COam depth 0.00 - 0.05 m increases when compared to the CMa system; There were not significant differences in the oxidizable fractions (F1, F2, F3 and F4) of the organic carbon in the areas of CMa and CMe.