Volume 26, Number 1, 2002

Land capability classification is a very complex, time-consuming task involving interdisciplinary knowledge and a huge amount of data. The objective of this paper was to develop a tool (CAP_USO), using an expert system technique, to determine land capability. The system was developed with knowledge acquired from literature and interviews with experts of these field. The classes and subclasses were determined taking into account twelve factors presenting restriction to land use and land capability was also determined by seven experts. The […]

Natural grassfields developed on sandy soils from Northern Uruguay are formed by communities of forage species, composed mainly of seasonal growing grasses, with low biomass production during the fall/winter period. The objective of this study was to evaluate the effect of herbicides, applied on native grassfield to established winter forage species, on soil properties and root biomass. This experiment began in 1994 and was established as a complete block design, with three replications. In the main plots, to establish winter-growing […]

The use of green manure to establish diversity and equilibrium of a crop system is one of the paragons in modern agriculture.Soil samples and green manure species intercropped with maize were evaluated in a field experiment, from 1995 to 1997, carried out in an Aleudalf Soil, located in Piracicaba (SP)Maize seeds were planted at 0.90 meter spacing within lines totaling 50,000 plants per hectare.The treatments were performed with four green manure species: dwarf mucuna (Mucuna deeringiana (Bort.) Merr), dwarf pigean […]

Bank erosion causes destruction of the area near the river, contributes to the degradation of large areas and causes catastrophic effects on the environment as well as a rupture of the environmental balance. This research was developed to quantify bank erosion rates, from February 1999 to July 2000 and to study the possible causes of the process. For the San Francisco River the pins and pegs methods were used to measure the erosive rate, with the successive profiling being used […]

For most conditions, nitrogen is the nutrient that most affects corn yield.Nitrogen management should meet this crop requirement with a minimum environmental risk.To achieve this goal, nitrogen fertilization recommendation should be as precise as possible.The overall adoption of no-till and cover crops in Southern Brazil demands an adaptation of such recommendation.This recommendation was based on the CFS-RS/SC (1995) and its main modification was taking into account the contribution of the previous cover crop to N availability, besides the organic matter […]

An experiment was carried out at the Soil Science Department of Federal University of Lavras (MG), from November/1999 to January/2000, aiming to evaluate the survival of strain and isolates of rhizobia, in heavy metal contaminated soil.The possible relationship between rhizobia tolerance in culture medium and its survival in contaminated soil was also verified.From a group of 60strains/isolates tested at a previous study for metal tolerance in YMA medium, two out of the most tolerant microorganisms [BR-4406 (strain recommended as inoculant […]

This study was carried out to evaluate chemical changes and corn growth in an Albaqualf soil.The tannery wastes used were primary sludge with Cr at the rates of 13.8 and 27.6Mgha-1 corresponding to 250 and 500mgkg-1 of Cr soil, respectively, and the sludge from liming, at the rates of 10.25 and 20.50Mgha-1. The experiment was conducted in a greenhouse during 108days.The liming sludge increased pH (4.9 to 5.8), soil Ca (0.5 to 3.2cmolcdm-3) and resulted in corn yields similar to […]

Pesticide kinetics and sorption allow to predict the equilibrium time of the reaction and to speculate over the reaction mechanisms involved.Therefore, their study is fundamental to understand the environmental fate of pesticides.The aim of this research was to evaluate the sorption and kinetics of the fungicide chlorothalonil in five distinct soils with different organic matter contents of the state of São Paulo (Brazil): Neossolo Quartzarênico órtico (RQo), Latossolo Vermelho distroférrico (LVdf-1 e LVdf-2), Latossolo Vermelho perférrico (LVj), and Gleissolo (G).The […]

Maximum liming efficiency depends not only on the quality of the corrective material but also on appropriate incorporation according to depth and homogeneity.Based on this, this work aimed to evaluate the effect of limestone incorporation ways on the production of black oat and on the correction of acidity in soil profile.An experiment was carried out in a Typic Acrustox loamy texture, in the area of the Triângulo Mineiro in Uberlândia (MG) from May 1995 to February 1996.The experiment was arranged […]