Soil organic matter can be analyzed on the basis of the different fractions. Changes in the levels of organic matter, caused by land use, can be better understood by alterations in the different compartments. The aim of this study was to evaluate the effect of different management systems on the labile and stable organic matter of a dystrophic Red Latosol (Oxisol). The following properties were determined: total organic C and total N (TOC and TN), particulate organic C and particulate […]

The conversion of native vegetation into agricultural areas can modify soil organic matter content and decomposition and synthesis processes and therefore the nutrient avalilability. The aim of this study was to evaluate the chemical and physical soil properties (0-15 cm depth) in a toposequence characterized by planted pasture beside the native Cerrado vegetation cover. The study was carried out in Colméia, State of Tocantins. Ten sampling points were determined (five samples in native vegetation and five samples in pasture) for […]

Phosphorus (P) deficiency is one of the most widespread limitations to the establishment and maintenance of pastures in tropical areas. This deficiency is mainly due to the low soil P content and adsorption/precipitation processes. The purpose of this study was to evaluate the influence of manure and lime applications on the residual effect of phosphorus applied to common bean on phosphorus nutrition and yield of Brachiaria brizantha grown in succession. Four experiments were conducted in a greenhouse, in a completely […]

The soil quality of a crop-livestock system can change according to the pasture and soil management. This research was carried out in Otacilio Costa, Santa Catarina State, southern Brazil, on a Humic Cambisol previously used with native grass pasture for 9 years, desiccated in May 2003, for use with ryegrass (Lolium multiflorum) pasture in the winter and corn in the summer. A split plot design was used, consisting of pasture management systems and soil tillage systems prior to the summer […]

The search for production forms that meet the increasing worldwide demands, maintaining the potential of the natural resources and in a systemic view of the social, economic and environmental sustainability, must be everybody’s interest and above all a concern of professionals of agrarian sciences. Aiming at a contribution in this direction, the effect of no-till and cultivated pasture production on the physical and water properties of a Typic Haplustox (Distrophic Red-Yellow Latosol) were evaluated. The study was conducted on a […]

Little is known about the changes in different soil organic matter (SOM) fractions under short-rotation eucalypt plantations. This study aimed to evaluate the impact of eucalypt cultivation on C stocks of several organic matter fractions in soils previously covered with degraded pasture, as well as to identify which SOM fractions are more sensitive indicators of land use change impacts. The study was conducted at two sites (Belo Oriente and Virginópolis) with commercial short-rotation eucalypt plantations in the Rio Doce Valley […]

Through the densimetric fractionation it is possible to study the physical protection of soil organic matter (SOM). High density solutions of sodium iodide (NaI) or sodium polytungstate (SPT) have been indistinctively used for this purpose. This study aimed to assess: (a) the capacity of these two solutions at a density of 1.8 g cm-3 (NaI-1.8 and SPT-1.8) and of SPT at densities of 2.0 (SPT-2.0) and 2.2 g cm-3 (SPT-2.2) to increase C recovery in the free light fraction (FLF) and occluded light fraction […]

Soil management systems, with crops under no-tillage (NT), crops (soybean) in rotation with pastures under NT and permanent pastures (Brachiaria sp.), were evaluated for soil aggregation and aggregate stability. Three long-term experiments (9 and 11 years) in the state of Mato Grosso do Sul were sampled in the layers 0-5, 5-10 and 10-20 cm for determination of the aggregate stability in wet and dry sieving. The mean weight diameter (MWD) and the aggregate stability index (IAS) were calculated. In all experiments, the […]

Cattle ranching is one of the main economic activities in the agrosystem of Itapetinga, state of Bahia, Brazil. This activity is known to cause direct impacts on soil, subsoil and vegetation. This study aimed at verifying changes in soil chemical characteristics and texture under different vegetation covers in the cattle ranching region of Itapetinga by sampling soils in a primary forest-secondary forest-pasture sequence. Soil samples were collected along a transect with 36 small trenches, 60 cm deep, spaced 5 m apart (12 […]

Several studies reveal that the substitution of native vegetation by agricultural systems results in decreases in the C and N soil organic matter pools. Aiming to test the hypothesis that management practices favoring organic residue inputs promote increases in the most sensitive organic matter pools, the present study intended to study areas of an organic management system of acerola fruit production and a conventional cultivation area cropped with carrot and beet in crop rotation with corn. These areas belong to […]