SciELO - Scientific Electronic Library Online

 
vol.70 issue3Terrestrial and orbital spectral models for the determination of soil attributes: potential and costsChanges promoted by management in Oxisol, Rondônia, Brazilian Amazon author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Bragantia

Print version ISSN 0006-8705

Abstract

ROSSI, Celeste Queiroz et al. Humic fractions of organic matter in soil cultivated with soybean on straw of brachiaria and sorghum. Bragantia [online]. 2011, vol.70, n.3, pp. 622-630. ISSN 0006-8705.  http://dx.doi.org/10.1590/S0006-87052011000300018.

The soil organic matter (SOM) is the waste product of the biota, mainly of vegetables, partially decomposed and synthesized in various stages of complexity and structural diversity. The dynamics of organic matter influences the main chemical, physical and biological processes of soils, and often determines soil fertility. The objective of this study was to quantify the fulvic acid, humic acid and humin content and evaluate the stock of these fractions in an Oxisol cultivated with soybean on straw of grass and sorghum in a savanna, Montividiu county (GO). Soil samples were taken at three depths in an area with grass growing between soybean crops (SB) and the other with the cultivation of sorghum between soybean crops (SS). The chemical composition of total organic carbon (TOC) and chemical fractionation of soil organic matter were evaluated. From these values, the carbon stocks in each fraction were quantified. There were significant differences for the TOC levels between all systems evaluated and in all soil depths. Regarding the chemical fractions of organic matter, there was a predominance of the humin fraction (C-HU) as compared to the the humic (C-FAH) and fulvic (C-FAF) acid fractions in the two samples evaluated.

Keywords : organic matter; chemical fractionation; no-tillage.

        · abstract in Portuguese     · text in Portuguese     · pdf in Portuguese