Volume 25, Number 1, 2001

This paper presents data of an experiment carried out in a Yellow Latosol amended with sewage sludge and municipal waste compost where sugar-cane was grown for two years. The experiment design was a random block with 9 treatments and 4 replications. The treatments were: tr1  – mineral fertilization + CaCO3; tr2, tr3; tr4 and tr5 – levels of sewage sludge (respectively, 0; 33; 66 and 99 Mg ha-1, in the first year, and 0; 37; 74 and 112 Mg ha-1, in the second year, in […]

Compaction is one of the main causes of degradation of agricultural soils and it has been evaluated through several indicators of: (a) soil structural quality for crop growth, such as the least limiting water range (LLWR), and (b) load support capacity of the soil, i.e., the preconsolidation pressure (σp). This research was carried out with the objective to relate the LLWR and the σp, as well as to determine critical pressures values that can be applied to the soil without […]

To study iron and aluminum oxide characteristics, samples of soils developed from different parent materials and with different development degrees were selected and collected from MG, ES, RS and RR states. The clay fraction was analyzed by X-ray diffraction (XRD), differential thermal analysis, thermogravimetry and electron microscopy. Al, Si and microelement contents were determined from ammonium oxalate (Ox) and dithionite-citrate-bicarbonate (DCB) extractions. Overall, goethite (Gt) was the main iron oxide in the clay fraction. Only the soils developed from basalt […]

The main objective of this work was to characterize the magnetic minerals and to identify their pedogenic transformation on a steatite-forming soil of Minas Gerais, Brazil. The iron-rich spinel phase was characterized by chemical analysis, powder X-ray diffraction, Mössbauer spectroscopy, with and without an externally applied magnetic field of 6 tesla, and saturation magnetization measurements. Nearly stoichiometric and well-crystallized magnetite was the only magnetic mineral actually detected. The cubic unit cell parameter of the fresh rock magnetite was found to […]

Carbon and nitrogen mineralization rates were determined in samples from a sandy latosolic Red Yellow Podzolic soil, taken at three depths, 0-20, 20-40 and 40-60 cm, during 10 years of sugarcane cultivation, using plots with and without N fertilization (60 kg ha-1 of N, as urea). N mineralization was measured using the incubation – percolation technique and C mineralization by absorbing the C-CO2 in 1 mol L-1 NaOH. Overall, N mineralization was higher (13%) in the treatment with N fertilization than in that without fertilization during the […]

An experiment was carried out under greenhouse conditions to evaluate the effects of arbuscular mycorrhizal fungi (AMF) and, or rhizobium inoculation, with the addition of industrial waste from lactic acid production (Ferkal), on the growth of Mimosa caesalpiniaefolia. Plastic pots of 6 L of capacity were used, filled with degraded soil from clay extraction areas with four levels of the Ferkal residue (0, 50, 100 and 200 g dm-3). Six microbiological treatments were conducted: indigenous AMF; AMF Glomus clarum; rhizobium; indigenous AMF + Rhizobium; […]

Adding simple superphosphate or phosphogypsum to piles of manure or other organic residues has been recommended to reduce losses of ammonia by volatilization during composting. However, experiments have shown discrepant results when the efficiency of these additives and the adequate rate of application are evaluated. This discrepancy could possibly be explained by differences in the residual acidity of the additives utilized in those experiments. To check this hypothesis, a laboratory experiment was carried out using samples of phosphogypsum, simple superphosphate […]

A field experiment was conducted in the state of Paraná, Brazil, to evaluate the effect of liming on soil acidity, soil nutrient availability and yields of maize and soybeans on a Red Latosol (Oxysol), which had been cultivated for three, six and nine years under no-tillage (NT). Lime was broadcasted to the soil surface in four rates- 0, 33.3, 66.7 and 100% of the amount calculated to increase the soil base saturation (V%) to 70%; an additional treatment consisted of […]

The most commonly studied phosphorus fertilizer placements in maize crop are scattering and furrow  –  localized. However, double furrow intermediary application is also possible, and may increase the fertilized soil fraction and fertilization efficiency. This research was carried out to evaluate the effects of fertilizer placement and doses of phosphorus fertilizer under maintainance fertilization of a corn crop, in a Dark-Red Latosol, in Triângulo Mineiro, Uberaba (MG, Brazil), from October 1995 to April 1996. The treatments consisted of the following […]

The aim of this work was to study the extraction of available boron using hot water and CaCl2 5 mmol L-1, and a microwave oven as the heating device. Boron was determined using azomethine-H. The influence of some soil characteristics on the performance of the extractants, was also studied. Corn plants were grown in a greenhouse, in a completely randomized block design, using 17 soil types and 6 B rates (0.0, 0.15, 0.30, 0.60, 0.90 and 1.5 mg dm-3) in a factorial with three […]