Volume 25, Number 4, 2001

A considerable fraction of the area under natural pastures in the state of Rio Grande do Sul (RS) – Brazil, presents acid soils and, if correctly managed, can be used for grain production. The objective of this study was to evaluate the changes in the chemical characteristics of an acid natural pasture field soil after receiving lime and being cultivated under different managements. Two experiments were conducted: one in the field and the other in soil columns in the laboratory. […]

Amelioration of degraded soils is time-consuming and expensive. Green manure and cover crops have been widely used in this remediation process since these plants produce a large amount of phytomass at a low cost, especially if they are tolerant to soil acidity. This study was carried out to evaluate the effect of liming on dry matter yield of the following 16 species, under greenhouse conditions: eight winter crops (Lollium multiflorum, Avena strigosa, Lathyrus sativus, Lupinus angustifolius, Pisum sativum, Secale cereale, […]

Part of the swine manure from confined production is still improperly disposed into water streams and small rivers in southern Brazil. An alternative disposal method would be to use this animal residue as a soil fertilizer. However, repeated applications in the same area may cause nutrient build up to phytotoxic levels and could lead to surface and subsurface water pollution. The objective of this study was to evaluate the effect of Zn addition to the soil on corn dry matter […]

Nitrogen and potassium applications affected the nutrient concentration and accumulation of sweet pepper, cultivar Mayata, grown in a protected environment. An experiment was conducted in a protected environment in Eutrostox, during 34 weeks from November, 1996 to August, 1997, with the following treatments: control and combination of three rates of N (13.3; 26.6 and 39.9 g m-2) and three rates of K (5.5; 11.0 and 16.6 g m-2). All plants were watered by trickle irrigation and the urea and KCl […]

An experiment was carried out at the Soil Science Department of Universidade Federal de Lavras, in Lavras (MG). in November 1998, to study the effect of aluminum on the initial growth of two forest species, under greenhouse conditions using a nutrient solution. After two weeks in dilute nutrient solution to 1/3 and without aluminum, two Moringa (Moringa oleifera) and two Angico (Anandenantha peregrina) plants were transplanted to 1.5 L pots, and grown in nutrient solution. The aluminum levels were 0.0, […]

The evaluation and classification of soybean cultivars, based on their tolerance to deficient or excessive boron levels, may be relevant when recommending fertilizers and amendments, and for plant breeding programs. This research aimed to study the response of four soybean cultivars to doses of B added to the nutrient solutions. The experiment was carried out under greenhouse conditions, at the experimental station of Instituto Agronômico, Campinas, São Paulo, Brazil in 1998. The soybean cultivars IAC-1, IAC-8, IAC-15 e IAC-17 were […]

Phosphorus has very low mobility into the soil, but in spite of this, it has been applied on the soil surface on some soil tillage systems. The efficiency of this form of application is not well known yet but can be affected by the soil pH and type of phosphate applied. This study aimed to assess the effect of the application method (mixed into the soil or on the surface, without incorporation) of phosphate fertilizers (diammonium phosphate, triple superphosphate, and […]

Fragipans and Duripans are frequently found in soils developed from sediments of the Barreiras Formation, in the low coastal plateaus of northeastern Brazil. Previous studies in arid regions have attributed Duripan cohesion to the amorphous silica. However, the Duripans and Fragipans in northeastern Brazil are located in semi-arid and high annual precipitation level zones (1.500 to 2.000 mm year-1). This study, based on a detailed characterization of soils from four depressions with different sizes, aimed to propose an evolution scheme […]

The influence of parent materials, Pre-Cambrian rocks, and colluvial and alluvial sediments derived from them, as well as their topographical position in the soil genesis were studied in a toposequence representative of the Baixada Litorânea Fluminense landscape, at the Federal Rural University of Rio de Janeiro, Brazil. Six soil profiles, located on the shoulder position (P1 and P2), backslope (P3), footslope (P4 and P5), and foot slope position (P6) were analyzed. The pedogenic processes and soil properties were related to […]

Six soil profiles were selected in a drained lowland area at Coruripe Sugarmill, aiming to characterize acid sulfate soils occurring in the lowplain of the Coruripe River Valley, in the coastal humid zone of the state of Alagoas. The soils were morphologically characterized, and samples were taken from each horizon to determine particle size distribution, bulk and particle density, total porosity, pH (H2O and KCl), organic matter, exchangeable bases and CEC, soluble sulfate and electrical conductivity of the saturation extract. […]