Soil Physical Attributes and Organic Carbon in a Cohesive Yellow Latosol (Oxisol) Under Different Soil Management Systems in the Coastal Plains of Bahia, Brazil

Although soil physical attributes are determining factors of soil quality and for root development of crops, they are often neglected when dealing with soil management, which refers only to fertility. The objective of this work was to evaluate soil physical characteristics, organic carbon content and carbon stock levels in yellow Latosol cohesive distrophic coastal plains of Bahia, Brazil, where different soil management systems were implemented. Soil texture, water dispersible clay, flocculation index, soil density and porosity, liquid limit, plastic limit, plasticity index, stability of aggregates, organic carbon content and resistance to penetration were evaluated from soil samples collected in the 40 cm-top soil. The different soil plot covers consisted of (i) Eucalyptus with grasses (EGR), (ii) Eucalyptus with spontaneous vegetation (EVE), (iii) fallow (POU), (iv) pasture (PAS), and (v) native forest (MN). It was found that EVE and MN contributed to greater stability of larger aggregates in the 20-40 cm-soil layer compared to EGR, PAS and POU. The high organic matter contents of soils of the cultivated plots (EVE and EGR) increased the limits of consistency. Soil management systems with Eucalyptus and pasture contributed to accelerate the oxidation process and the loss of C.