Attributes of soil, climate and crop management were characterized in ten growing coffee plantations in the western region of São Paulo State. The purpose of this work was to identify the main limiting productivity factors and develop a simple multivariate model to explain observed yield in the period between 1984 and 1989. Over two thousand traits were initially analyzed by simple correlation to the final yield, and the significant ones, with at least 5% level according to the Student test […]

A soil sequence (Oxisol → Ultisol → Alfisol) was studied on the border of a plateau, which is the oldest regional surface near the Piracicaba river valley (southeastern Brazil). Seven pits were identified, sampled and morphologically described under the different segments of the sequence (end of summit, shoulder, backslope and footslope). A bi-dimensional sketch of the soil horizons was drawn. Undeformed soil samples were taken for micromorphological studies, and mineralogical, chemical and granulometric analyses were performed. The very clayey Oxisols […]

Through profile morphology and physical analysis (texture, bulk and particle densities, pore size distribution, water storage and retention, and field capacity determined “in situ”), the behavior of a yellow Latosol located in Cruz das Almas (BA), Brazil, was studied when subjected to irrigation. The results made showed that the AB and BA horizons were hard (cohesion), mainly when dry, becoming a strong mechanic impediment fot root growth , aeration and water movement; due to the presence of the hard layer, […]

This study was conducted to examine the distribution and nature of Fe oxides in plinthic soils on the sediments of Barreiras Group (in the state of Piauí) and Itapecuru Formation (in the state of Maranhão) in Northeastern Brazil. Four pedons were selected: a “plinthic, dystrophic, epieutrophic Gray Podzolic with low activity clay” and a “dystrophic Plinthosol with low activity clay” (both Plinthic Kandiustalfs) on the Barreiras sediments, as well as an “eutrophic Plinthosol with low activity clay” and an “allic […]

Tensiometers were installed in a 25 m2 area plot, every 15 cm, at depths varying from 30 to 240 cm, with three repetitions, to determine the matric potential (φm) of a “Terra Roxa Estruturada Latossólica” soil. Its volumetric water content was also indirectly measured by using the soil water retention curve. The θ-method (Libardi et al., 1980) fitted the soil redistribution profiles (θ vs t) with determination coefficients (R2) greater than 0.98. The hyphotesis of a unit hydraulic gradient was […]

A slope with a soil sequence over sandy Perm-Carboniferous sediments from the Itararé Formation with clayey oxidic soils was studied. This area is representative of the low hills with smooth relief of the low valley from the Piracicaba river. The area is located in the Piracicaba municipality about 22o 47’S & 47o 35’W within São Paulo State Peripheral Depression. The sequence comprises a clayey Dark-Red Latosol (Rhodudox), on the hill top transitioning downwards to a Dark-Red Latosolic-Podzolic Intergrade (Rhodic Kandiudox). […]

A study on the genesis of Humic Oxisols and its relationships with the evolution of the landscape was carried out in an area of 5,750 ha in the central segment of the South of Minas Gerais Brazil. Two morphopedological systems (SMI and SMII), representative of the regional geology and geomorphology were chosen. Pedological (chemical, physical, morphological, micromorphological) and geomorphological studies, as well as soil charcoal quantification and radiocarbon tating were performed in four profiles classified as: Humic Xantic Hapludox and […]

The objective of this work was to study the spectral reflectance of a Brown Latosol (Haplohumox) and “Terra Bruna Estruturada” (Tropohumult) developed from volcanic acid rocks which occur in the center-south region of Paraná, Brazil. These soil samples were collected at depths of 0-20 and 40-60 cm. The characterization, discrimination and estimation of the soil attributes were studied by their reflected energy determined at the wavelength interval of 400 to 2.500 nm using an IRIS laboratory spectroradiometer. It was possible […]

The state of Rio de Janeiro, Brazil, is characterized by three main geomorphologic formations, the landform constituted by crystalline rocks, exposed or covered by their alteration products; coastal tablelands, formed by Barreiras Formation Tertiary sediments; and alluvial floodplain sediments of Quaternary age. Differences between parent material and topography and their influence on soil genesis have been the main subject of studies in Rio de Janeiro. The objective of this study was to analyze the behavior of extractable forms of iron, […]

This study was conducted to characterize the morphology, physics, chemistry, mineralogy and pedography of soil profiles with Mollic horizon at Nazaré da Mata, Pernambuco, Brazil, 1995. Three soil profiles involving Litosol, Reddish Brunizém and Red Yellow Podzolic were morphologically described. Samples were taken from each horizon to determine the physical, chemical (including humic fraction quantification), mineralogical and pedographycal properties. Based on soil properties and environmental conditions, it could be assumed that the surface horizons were developed from climate – vegetation […]