Volume 26, Number 3, 2002

A micropedological study was carried out in rehabilitated soils after bauxite mining, in sites dating from 1981 to 1987, compared with the Yellow Latosol, as reference, to subsidize soil indicators of rehabilitation. The study was located in Porto Trombetas, district of Oriximiná, northwestern Pará State. Micromorphological techniques, using EDS/SEM microprobe, optical and scanning electronic microscopy, were used in combination with chemical and physical analysis, at 0-10 and 40-50 cm depths. The Yellow Latosol showed a strong development of microgranular structure, […]

A green house experiment was conducted to investigate the effects of the application of solid urban waste compost at a rate of 30 g dm-3 (60 t ha-1), on 21 acid and five alkaline soils in relation to their organic carbon, total nitrogen, available phosphorous and sulfur contents. Compost from the São Matheus Treatment Plant (São Paulo, Brazil) was applied with or without dolomitic lime and mineral fertilizers. In alkaline soils, lime was substituted by gypsum. The experiment was carried […]

This experiment had the objective of assessing the influence of management practices (disk harrowing, Pueraria phaseoloides and mowing) on the soil’s bulk density and macro- as well as microporosity between the rows of rubber trees (Hevea brasiliensis) planted in 1992 in the highland of the State of São Paulo. A Dark Red Latosol, from Jaboticabal County and a Yellow Red Podzolic from Tabapuã County, São Paulo State were sampled at four depths (0-10, 10-20, 20-30 and 30-40 cm) in the […]

This study presents an alternative procedure for the extraction of micronutrients from soil samples for fertility evaluation. Samples from an interdisciplinary program for soil analysis with different physical and chemical characteristics were subjected to DTPA extraction using focused microwave radiation energy. The microwave-assisted procedure (10 min) proved to be remarkably time-saving for Cu, Mn, and Zn extraction when compared to the time consume of conventionally prepared samples (120 min), using mechanical stirring at room temperature. The development of a single […]

The high availability of metallic ions in the soil, including Mn2+, may inhibit arbuscular mycorrhizal fungi (AMF), slowing down spore germination and, consequently, the mycorrhiza formation, therefore decreasing the symbiotic effectiveness. The aim of this study was to evaluate the effect of Mn2+ ions on spore germination in six AMF species of the genera Glomus, Acaulospora, Gigaspora and Scutellospora under in vitro conditions. Different Mn2+ doses (15, 30 and 75 mg kg-1) as MnCl2.4H2O were added to a washed sand […]

The Southern part of Minas Gerais State is an important coffee producer region in Brazil. Though coffee yields are still quite low. Plant tissue analysis based on sufficiency ranges as well as the Diagnosis and Recommendation Integrated System (DRIS) are important tools for the correct use of fertilizers. However, as local standards are not yet obtained for Coffea arabica in that region, recognition as well as calibration of reference values used elsewhere are called for. Objectives of this study were: […]

Rainfall erosivity at Teodoro Sampaio was studied through methodology proposed by Wischmeier and Smith (1958). A set of 812 erosive individual rains was selected, from a continuum series of nineteen years of nonrecording rain gauge data, according to Wischimeier (1959), Wischmeier and Smith (1978) and Cabeda (1976) and proposed with changes by Carvalho (1987). All the selected rains were computed by the package of Cataneo et al. (1982). The rainfall erosivity factor computed was 7172 MJ mm ha-1 h-1 y-1, […]

The climate of Southern Brazil is affected by climatic anomalies called “El Niño” and “La Niña”. During the first phenomenon, the precipitation volume is higher than normal. On the contrary, water deficits are observed during “La Niña”. Data of soil and water losses associated to these climatic anomalies are scarce, making their study the main objective of this work. An experiment on soil loss by natural rainfall was carried out on that account in Santa Maria, Rio Grande do Sul […]

For every type of soil, the water retention curve is specific and depends on several soil features. This study was carried out to evaluate the influence of soil attributes on water retention in Red Latosol (Haplustox) and Red Latosol (Eutrustox) under different management and use systems. The use systems were: cotton, sugar-cane and woods. The granulometric composition, bulk density, organic matter, Fe2O3 and Al2O3 contents, as well as the water retention curve were determined for soil samples from different depths […]