Volume 27, Number 4, 2003

From 1920 on, Ferralsols of the Planalto Médio region in the State of Rio Grande do Sul, Brazil, originally under forest vegetation, were converted into agricultural land, while the same soils under grassland were converted in the 1960-ies. Thereafter, chemical soil properties were affected by intense cropping, mainly of soybean and corn. To evaluate how the time of agricultural land use affected two Ferralsols in the Fortaleza dos Valos county, State of Rio Grande do Sul, pedon samples of a […]

This field experiment was carried out at the Fundação Agrária de Pesquisa Agropecuária [Agrarian Foundation for Agricultural and Cattle Research] (FAPA), in Guarapuava, State of Paraná, Brazil, during the growing seasons of 1999 and 2000. The objective was to verify residual effects of nitrogen fertilization on maize crop under a no tillage system, in presence and absence of white clover and grazing animals. The experimental layout was a completely randomized block design with three replications. The treatments were arranged in […]

Soils with a planic B horizon underlying a textural B horizon and, therefore, not regarded as Planosols in the Brazilian System of Soil Classification (SIBCS) were characterized and classified. Three representative soil profiles were selected in the county of Ouricuri, Araripina micro-region, within the Sertão Zone of Pernambuco State, an area with a high density of planossolic soils. Soil profiles were morphologically described and disturbed samples taken from each horizon for physical and chemical analyses. Undisturbed samples were collected to […]

The spatial variability of some physical and chemical characteristics of a compound of soils under grapevine (Vitis vinifera-L) cultivation was studied in the county Vitória Brasil, State of Sao Paulo, Brazil. Main objective was research into the spatial dependence of these soil characteristics and their variability, frequency distribution and minimum number of soil subsamples for grapevine crop. Soil data were collected in grid sampling at 156 points, using geoestatistics for the data analysis. Highest variability was found for macroporosity (MA), […]

Eucalyptus and acacia species are widely used in agrosilviculture and reforestry practices. In order to evaluate the reconstitution of organic soil layers – i.e. the humic horizons -and establish relationships to the soil properties, the holorganic and hemiorganic horizons were sampled under Acacia mangium and Eucalyptus grandis plantations. These plantations lie in the tertiary tableland region in the North of Espírito Santo State, Brazil, and are part of the Natural reservation Area of the Vale do Rio Doce Company. Samples […]

Mathematical models for soil erosion prediction are of unquestionable validity for planning the use of agricultural soils. The Universal Soil Loss Equation (USLE) is an example of such models and estimates the expected annual mean losses of soil in a given site and for a given management system based on the parameters: rain erosivity (R), soil erodibility (K), slope length (L), steepness (S), soil cover and management (C), and conservation practices (P). With the objective of contributing to conservation planning […]

The model SWAT (Soil and Water Assessment Tool) was used to simulate alternative scenarios of land use in Ribeirão dos Marins watershed, in Piracicaba, State of São Paulo, Brazil, for the biennial period 1999/2000. Two scenarios were simulated. The first one (scenario 1) was based on the current land use except for the introduction of a continuous riparian buffer of 30 m along the drainage network and of 50 m around the springs, in accordance to Brazil’s environmental legislation. In […]

The SWAT (Soil and Water Assessment Tool) model was applied to simulate the sediment yield in the watershed Ribeirão dos Marins, in Piracicaba, Brazil, for the biennial period of 1999/2000. The application of this model requires georeferenced input data, provided by an interface between the model and a Geographic Information System (GIS). The watershed was divided into sub-basins, and parameters were separately determined for each area. The simulated sediment yields were compared to the observed data of a gauge station […]

Erosion is the most deleterious form of soil degradation. Besides reducing the productivity capacity for crops, it can cause serious environmental problems, such as sedimentation and pollution of water sources. Yet the use of sound soil management systems and well-planned support conservation practices can solve erosion problems satisfactorily. In order to obtain quantitative information on the subject as guidelines for conservation plans, an erosion experiment under natural rainfall was conducted on a very clayey soil (Typic Haplortox), in Santo Ângelo, […]

Tannery and coal residues are potential pollution sources in numerous regions of Brazil, mainly in the Rio Grande do Sul and Santa Catarina States. In order to evaluate the effects of tannery residue and coal mining refuse on soil properties and cultivated plants, a field experiment was carried out in 1996/97 at the UFRGS Experimental Station, in the Eldorado do Sul county, State of Rio Grande do Sul, Brazil. Corn (Zea mays L.) and soybean (Glycine max L. Merrill) were […]