Physical, chemical and mineralogical characteristics of soils from the meadow Region of Sousa (PB)
01/Apr/2003
Physical, chemical and mineralogical characteristics of soils from the meadows of Sousa (Paraíba State – Brazil) were studied, as well as the effect of alkaline and alkaline-earthy cations on humic substance stability. Furthermore, criteria of environmental distinction used by the small farmers and different forms of land use in the studied region were identified. Profiles from the classes Ustifluvents (Neossolo Flúvico), Haplustalfs (Luvissolo), Natrustalfs (Planossolo nátrico), and Usterts (Vertissolo crómico) were therefore selected, sampled and analyzed. Besides sodium, magnesium also […]
Micromorphological characterization and inferences on the genesis of semi-arid brazilian soils
01/Dec/2002
A detailed macro- and micromorphological investigation was carried out in two Ultisol (Argissolo Amarelo) and one Aridisol (Planossolo Nátrico) profile from a tableland surface of the San Francisco river basin in Petrolina, Pernambuco State, Northeastern Brazil. The study aimed to characterize the soils micromorphologically, evaluating their pedogenesis to help understand the soil diversity in the landscape. Results indicate that the three soils were developed from Post-Cretaceous sediments mixed with Pre-Cambrian crystalline rock weathered materials and, also, most probably, with materials […]
Stratigraphical discontinuities, tropical landscape evolution and soil distribution relationships in a case study in SE-Brazil
01/Sep/2002
On a regional summit surface in the county of Piracicaba (SP) within the Peripheric Depression of São Paulo, formed of discontinued flattened tops, there is an abrupt transition between a Typic Hapludox and a Kandiudalfic Eutrudox, together with two stoneline layers. Using stratigraphical, mineralogical, and cartographic studies, this transition and the soil distribution of this surface were studied, correlating them with the different parent materials and the morphoclimatic model of landscape evolution in Southeastern Brazil. The Typic Hapludox was formed […]
Land evaluation combined with climatic risk estimate for corn using geographic information system
01/Sep/2002
The objective of this work was to propose a methodology for land evaluation based on planting information, soil data extracted from a soil survey in a scale 1:50,000, and estimate of climatic risk, using a geographic information system (GIS). The reference area was the Jardim watershed, in the Federal District (Brazil). A water balance model was used to simulate the climatic risk for the corn crop (Zea mays L.), at nine different planting dates. Quantitative values for corn productivity parameters […]
Soil properties affected by land leveling at two paddy rice fields
01/Jun/2002
Soil or land leveling, a process of adequation of land surface, is being practiced in many rice-growing farms in the state of Rio Grande do Sul, Brazil. This process produces profound changes in the morphological, physical, chemical, and biological properties of the soil. To study these changes, test areas were selected with homogeneous surfaces where Planosols occur and on which land leveling was performed for eight years, one year, and one month and with original soil, at São João do […]
Evolution of Espodosol Ferrocarbic to Haplic Gleisol in the Serra do Mar plateau, rio Guaratuba, São Paulo, Brazil
01/Jun/2002
The Guaratuba watershed is located at the “Parque Estadual da Serra do Mar” and has its headwaters in the Atlantic plateau. The area has a gneissic bedrock in a parallel hilly relief with high slope gradient, covered by the Atlantic forest consisting mostly of low size trees. The climate is humid tropical with rainfall of 2,000 mm year-1, with no dry season. The predominant soils are Red Yellow Argisol (Typic Kandiudults or Paleudults and Typic or Lithic Hapludults) and Haplic […]
Experimental use of ground-penetrating radar (GPR) to investigate tablelands in the northern coast of Bahia, Brazil
01/Jun/2002
Nine profiles were studied along a toposequence developed on Barreiras Group sediments, in Fazenda Rio Negro, Entre Rios, Bahia, Brazil. Besides conventional analysis, an electromagnetic probe through GPR – Ground-Penetrating Radar was employed. The objective of this study was to analyze the use of this tool in the acquisition of information on features occurring underground, by comparing the radargrams and pedologic descriptions obtained in the area. The equipment used was a Geophysical Survey model, with an 80 MHz antenna. The […]
Pedogenesis in an oxisol-spodosol sequence at the upper rio Negro region, Amazonia
01/Jun/2002
This paper deals with the genesis of hydromorphic sandy soils with spodosol morphology found in extensive flat surfaces, in which isolated zones with undulating relief emerge, containing well drained oxisols. The objective of this study was to explain the existence of pedogenetic relationship in an oxisol-spodosol system, and to verify the possible development of the sandy materials as a consequence of oxisol transformation. For this purpose, we characterized the morphology of the soils and their physical, chemical and mineralogical attributes. […]
Characterization and classification of acid sulfate soils in lowlands of Coruripe river valley, Alagoas, Brazil
01/Dec/2001
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. […]
Evaluation of grapevine foliar nutrition products
01/Dec/2001
Grapevine nutrition is a fundamental factor for quality production. Often, for physiological mainly nutritional reasons, problems of reduced bud break occur, reflecting in grapevine productivity. This experiment was carried out to evaluate the effectiveness of the foliar formulation of macro and micronutrients, activated with polihexose in grapevine production, during two years, in a vineyard of the cv. Merlot grafted in the rootstock R110, formed in lira system, located in Monte Belo do Sul (RS), Brazil. Eleven treatments were used, consisting […]
