Knowing the susceptibility of a soil to compaction is important to adjust soil management, tillage practices, and traffic to cause minimal detrimental effects on soil properties. The objective of this study was to determine the preconsolidation pressure (σ’p) and the compression index (Cc) at two depths of two soils under no-tillage and conventional tillage, including a wide variation of the state of compaction. Undisturbed soil samples were collected with rings (5.4cm wide and 2.0cm high), at 0 to 2 and […]

The arbuscular mycorrhizal fungi (AMF) are ubiquitous establishing symbiosis with a large number of plants in spite of soil contamination with heavy metals.This study aimed to evaluate AMF occurrence and diversity in soils of four locations cultivated with grass species and contaminated with heavy metals as a result of Zn extraction and industrialization. AMFs were found in all locations, with species predominance being affected by heavy metal concentration in soil. Twenty one species were identified, belonging to the following genus: […]

The geochemical behavior in soil alteration profiles in Lavras (MG), Brazil, was evaluated during the process of soil formation leading to the formation of argillic horizons, in parent material ranging from acid, intermediate to mafic geochemical composition.Along each profile, from the consolidated bedrock to the solum, geochemical analyses of major elements-main oxides were performed, calculating the gains and losses through a mass chemical balance.The results showed a moderate loss of SiO2, bases leaching, and a slight relative enrichment of Al, […]

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 […]

Hematites were synthesized with different degrees of isomorphic substitution (IS) of Fe for Al to a maximum of 16Almol%.The minerals were characterized by X-ray diffraction, total chemical analysis, extraction of iron and aluminum soluble in ammonium acid oxalate (Feo+Alo), determination of the anion exchange capacity (AEC) and specific surface area (SSA).The results showed that the synthesis methods resulted in a minimum amount of impurities and that, in a general way, the foreseen values of isomorphic substitution were achieved.The SSA values […]

This study compares the chemical composition of the solution and exchange complex of soil in a 3-year-old irrigated vineyard (Vitis vinifera L., Red Globe cultivar) with that of adjacent clearing in the native hyperxerophyllic ‘caatinga’ vegetation. The soils are classified as Plinthic Eutrophic Red-Yellow Argisol; according to Soil Taxonomy they are isohyperthermic Plinthustalfs. Detailed physiographic characterization revealed an impermeable gravel and cobble covering the crystalline rocks; the relief of this layer was more undulating than the level surface. Significant higher […]

Besides its low cost, solar energy use in soil disinfestation presents no risks for human health and the environment. However, its effects on beneficial microorganisms are not well known. This study evaluated the effect of a solar collector and solarization on an indigenous population of arbuscular mycorrhizal fungi. Inoculum potential of mycorrhizae, determined by the most probable number method, decreased, respectively, 93 and 99% when soil was treated during 30days by solarization and solar collector. Mycorrhizal colonization of maize plants, […]

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 […]

Two experiments were carried out simultaneously in a greenhouse to evaluate the effects of plant age and regrowth periods on soil and plant phosphorus critical levels for two tropical forage grasses. Treatments corresponded to the 2x5x5 factorial arrangement in the initial growth study, and the 2x2x5 factorial in the regrowth study.Those factorials consisted of two species (Brachiaria decumbens cv. Basilisk and Panicum maximum cv. Mombaça); five plant ages (14, 28, 42, 56, and 70days after emergence) in the initial growth […]