Volume 31, Number 1, 2007

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 […]

The soil quality (SQ) evaluation is an important part of agricultural planning. It allows the identification and improvement of high-yielding management systems with characteristics of environment preservation. This study was carried out in two long-term soil management experiments (10 and 15 years) in Rio Grande do Sul State, Brazil. The main objective of this study was to evaluate the effectiveness of the Soil Quality Kit (SQK) developed by the Soil Quality Institute – ARS – USDA, compared to traditional soil science […]

In western Santa Catarina state, Brazil, swine manure is commonly used as nutrient source for crops. The aim of this study was to evaluate the effects of swine manure on chemical attributes of a Red Latosol (Hapludox), cultivated with corn under no-tillage conditions. Two experiments were carried out using different rates of liquid swine manure (0, 40 and 115 m-3 ha-1 year-1), applied annually at corn sowing, from 2000 to 2004, in Chapecó and from 2001 to 2004, in Guatambu. After the last […]

Water erosion is the most deleterious form of soil degradation. Besides reducing the production capacity of soils for crops, it causes strong financial and environmental impacts, due to the nutrient losses associated with it. This research work was developed with the objective of quantifying water and soil losses, P, K, Ca, and Mg losses in runoff water and extracted P, and exchangeable K, Ca and Mg losses in runoff sediments, caused by rainfall erosion, in an experiment conducted under natural […]

The presence of organic ligands in the rhizosphere plays an important role in heavy metal solubilization in soils treated with sewage sludge. Low molecular weight organic acids exuded by roots and/or released by microorganisms are considered mobilizing agents of these metals. The present study determined Cd, Cu, Cr, Ni, and Zn solubilization kinetics in sewage sludge-treated soils using a mixture of four organic acids (acetic, citric, lactic, and oxalic) in 0.05 and 0.10 mol L-1 solutions. Based on the batch extraction method […]

Sewage sludge has been used in agriculture in many crops as an alternative to reduce environmental impacts and water pollution. Nonetheless there is a need to adjust rates and timing for each crop. Therefore, the effects of sludge application on earliness and heart-of-palm yield were studied in peach palm in a field experiment carried out in Ubatuba, SP, Brazil. Four annual nitrogen rates, (0, 0.5, 1.0 and 2.0 times the recommended amounts for the crop) were tested in a complete block […]

Soil management systems and fertilization types make differentiated amounts of mineral elements in the soil profile available. The objective of this study was to verify alterations in chemical attributes of a Red Latosol (Typic Haplustox) of Brazilian Savannah under organic and mineral fertilization, vegetation cover in no tillage and conventional tillage systems, and with bean and cotton crops. The experiment had a randomized complete block design with split-plots. Two treatments of soil preparation (no tillage and conventional tillage) were installed […]

The mixture of forage seeds with mineral fertilizers can make intercropping systems possible by reducing competition with the grain-producing crop. However, if the mixture is prepared too early before sowing, the emergence and establishment of the forages can be negatively affected. Therefore, experiment were carried out in laboratory and greenhouse conditions, in Botucatu, São Paulo, to evaluate Brachiaria brizantha seed germination as related to the time of contact with distinct chemical fertilizers. The experiment had a completely randomized block design, […]