FRACTIONS OXIDIZABLE OF ORGANIC CARBON IN AGROECOLOGICAL BASE SYSTEMS IN PRODUCTION OF BAHIA SEMIARID

Abstract

The objective of this study was to quantify the total contents and the organic carbon variation of soil with different degrees of lability in areas under organic fruit production system in the semi-arid Bahia. The study was conducted at Organic Bocaiúva Chacara located in Humble district, Feira de Santana, Bahia. The selected areas under different uses were: (CIT) Cultivation of citrus, (MAR) passion fruit cultivation and (ABA) area under pineapple cultivation. For comparison it was also evaluated an area under native forest system (MN). For each use system soil samples were collected at 0-10 and 10-20 cm in four replications. To obtain the different fractions was used doses of 2.5 and 5 ml of concentrated H2SO4, which corresponded to concentrations of 3 and 6 mol L-1, respectively, while keeping constant the concentration of K2Cr2O7 in 0.167 mol L-1. Total organic carbon was obtained by wet oxidation with an external source of heat. The results show that the organic production systems studied non labile C is the highest percentage in the formation of COT. The SEA area presented organic carbon values in the various fractions and the COT like reference system (MN), which indicates that the system is being handled properly, causing no decrease in the levels of organic matter in the soil

Keywords

• Organic farming
• soil organic matter
• Organic production systems
• labile carbon