Volume 29, Number 2, 2005

The effects of sewage sludge doses on the root system of peach palm were studied in a field experiment, in randomized complete blocks, carried out in Ubatuba, state of São Paulo, Brazil. The trial was set up in July 2001, with a density of 5,000 plants ha-1. The sewage sludge doses (79.7 % water content) were 0, 38, 76, and 152 t ha-1, which were equivalent to doses of 0, 100, 200, and 400 kg ha-1 of N. The treatments were applied in the planting furrow, and […]

This study reports on the use of GIS (Geographical Information System) tools for identifying and mapping landform units and soilscapes in a case study of a watershed in the region of Viçosa, Minas Gerais state, based on a topographical base map at a 1:50000 scale. Field work was undertaken to estimate the degree of accuracy of landform units / soilscape identification, obtaining an agreement of 72 % between the automatic and field work classification, and to correlate obtained soilscapes with dominant soil […]

Nutrient losses are influenced by the soil tillage system. In general, nutrient concentrations in runoff are higher in soil conservation tillage systems, whereas the total nutrient losses are higher in conventional soil tillage. The NH4+ and NO3– losses in water and mineral nitrogen in runoff sediment were determined under natural rainfall in the following tillage systems: six years of no-tillage (NT6), nine years of no-tillage (NT9), nine years of chisel plow plus disking cultivation (CD9), nine years of plowing plus […]

The mechanical penetration resistance of a soil strongly influences plant development since the root growth as well as the crop yield change inversely proportional to its value. The bean grain yield (GY) and the penetration resistance (PR) in a Dystrophic Red Latosol (Rhodic Ustox) located at the Experimental Station of the Faculdade de Engenharia/UNESP in Ilha Solteira county, São Paulo State, Brazil (22 º 23 ‘ latitude S; 51 º 27 ‘ longitude W), were analyzed in the crop year 2001/2002. The main objective was to work out […]

Three main stages are involved in particle-size analysis: pretreatment of samples to remove cementing and flocculating agents, sample dispersion and soil fraction quantification. This quantification requires the previous separation of the soil fractions. According to the size, coarse and fine sand fractions are separated by sieving, while silt and clay are separated by sedimentation. Some methods propose to calculate the silt proportion by subtracting the other soil separates from the original sample. In the Soil Physics Laboratory at the Federal […]

Soil hydraulic conductivity is an essential property and its quantification is essential for any study that involves soil water movement. Methods of determination based on internal drainage, such as the instantaneous profile method (IPM) are among the most commonly used, but their determination is restricted to the soil water range between saturation and field capacity. In order to obtain hydraulic conductivity for lower water contents, we propose an IPM that takes into account evaporation as well as a calculation routines […]

This work aimed at creating an educational project with elementary school students from the São Miguel community in Esperança county, state of Paraiba, Brazil. We encouraged the children to think about the importance of soil in their life, and also tried to use a pedologic terminology adapted to the students’ everyday language. The applied methodology followed Paulo Freire’s approach, which extrapolates the school context from the classroom and tries to reach out for as many people in the community as […]