3299 results

Chemical and biological properties of a tableland soil cultivated with sugar cane with and without straw burning

H. N. S. Mendonza, E. Lima, L. H. C. Anjos, L. A. Silva, M. B. Ceddia, M. V. M. Antunes

01/Mar/2000

Two systems of sugar cane harvesting were compared: 1-previous burning (burned cane) and 2-straw spreading over the soil surface (green cane), over an area of Linhares Agropecuária S.A. plantation, in Linhares, Espírito Santo, Brazil. The soil was classified as Yellow Podzolic sandy over medium texture, developed from Barreiras Formation sediments. After six years of sugar cane cultivation (1989-1994), nutrient distribution, humified fractions, and soil microbial biomass dynamics were determined. The green cane system showed an increasing of soil carbon content […]

Erosive behavior of a pedological system of Umuarama, northwest of Paraná

J. E. Cunha, S. S. Castro, F. X. T. Salomão

01/Dec/1999

The town of Umuarama, Northwest of Paraná, presents sandy and medium-textured soil, derived from Cretaceous Caiuá Formation Sandstone. Besides the natural fragility of these soils, deforestation, use and generalized occupation have contributed to the identification of erosive processes. A slope next to the urban area was selected for a toposequence study aiming at a macro and micromorphological pedologic characterization followed by a physico-hydric characterization of the pedologic horizons. The data allowed to reach some important conclusions concerning material behavior, hydric […]

Heavy metal accumulation by continous use of phosphate fertilization and irrigation water in sugar cane-cultivated soils

J. F. G. P. Ramalho, N. M. B. Amaral Sobrinho, A. C. X. Velloso

01/Dec/1999

To verify if the use of phosphate fertilizer and polluted irrigation water increased the levels of heavy metals in soil, samples of one Yellow Podzolic and two Yellow Latosol soils treated with phosphate fertilizers since 1968, and a Cambisol irrigated with water from the Paraíba do Sul River since 1978, cultivated with sugarcane in Campos dos Goytacazes, RJ, were analysed for total contents of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn. The results from the soils that received […]

Influence of tree species on the herbaceous understory and soil chemical characteristics in a silvopastoral system in semi-arid northeastern Brazil

R. S. C. Menezes, I. H. Salcedo

01/Dec/1999

Studies from some semi-arid regions of the world have shown the beneficial effect of trees in silvopastoral systems, by promoting the formation of resource islands and increasing the sustainability of the system. No data are available in this respect for tree species of common occurrence in semi-arid Northeastern Brazil. In the present study, conducted in the summer of 1996, three tree species (Zyziphus joazeiro, Spondias tuberosa and Prosopis juliflora: ) found within Cenchrus ciliaris pastures were selected to evaluate differences […]

Physical properties and microbiological activity changes of an alic yellow latosol after cultivation with perennial fruit trees and cassava

A. L. Borges, J. C. Kiehl, L. S. Souza

01/Dec/1999

This study aimed at evaluating changes in the physical properties of an alic sandy-clay loam Yellow Latosol (Haplortox), located at Cruz das Almas, Bahia, Brazil, cropped for 15 years with banana, 38 years with citrus, 15 years with mango, and 14 years with cassava, compared with soil covered by native forest. In 1991, soil samples were collected for the A, AB, Bw1 and Bw2 horizons and soil bulk density, soil density, macroporosity, microporosity were determined, as well as the distribution […]

Alterations of the physical properties of a dark-red latosol (typic Acrustox) under different crops

A. Cavenage, M. L. T. Moraes, M. C. Alves, M. A. C. Carvalho, M. L. M. Freitas, S. Buzetti

01/Dec/1999

The present work had the objective to analyze the alterations of the physical properties of a dark-red Latosol (typic acrustox), under different use systems. In 1996, samples of soils were collected, under corn crop, pinus, eucalyptus, pasture, ciliary forest (after 10 years of cultivation), and native cerrado vegetation, in three depths (0,00-0,10; 0,10-0,20, and 0,20-0,40 m), in the experimental station from Faculdade de Engenharia de Ilha Solteira – UNESP, located in Selvíria county (MS). The experimental design was the totally […]

Estimation of surface roughness in a semiarid region from C-band ERS-1 synthetic aperture radar data

E. E. Sano, A. R. Huete, M. S. Moran

01/Dec/1999

In this study, we investigated the feasibility of using the C-band European Remote Sensing Satellite (ERS-1) synthetic aperture radar (SAR) data to estimate surface soil roughness in a semiarid rangeland. Radar backscattering coefficients were extracted from a dry and a wet season SAR image and were compared with 47 in situ soil roughness measurements obtained in the rocky soils of the Walnut Gulch Experimental Watershed, southeastern Arizona, USA. Both the dry and the wet season SAR data showed exponential relationships […]

NPK fertilization effects on soil fertility, mineral nutrition and growth of rubber trees

O. C. Bataglia, W. R. Santos

01/Dec/1999

The purpose of this study was to evaluate soil and plant responses to a continuous supply of NPK fertilizers on rubber trees [Hevea brasiliensis (Willd. ex Adr. de Juss.) Müell. Arg.], clone RRIM 600. The experiment was conducted on a Red-Yellow Podzolic Latosol sand/medium texture at Avaí, State of São Paulo, Brazil. A fractionated factorial experiment 1/2 (4 x 4 x 4) was used, with doses of 0, 40, 80 and 120 kg ha-1 of N, P2O5 and K2O, applied […]

Water infiltration in a dark-red podzolic under two types of tillage, using simulated rainfall with two intensities

M. C. Alves, M. S. V. Cabeda

01/Dec/1999

A field experiment, arranged in a four-replication split-plot design, was conducted in a Dark-Red Podzolic (Paleudult) to study infiltration rates, ponding time and initial runoff under conventional and no-tillage methods, plots cultivated with oats (Avena strigosa) and soybeans (Glycine max), using simulated rainfall with constant mean intensities of 63.0 and 87.0 mm/h. A small rainfall simulator with 80-100 and 80-150 Veejet nozzles was used, and the test sites had 0.81 m2. Smith’s model was adjusted to the observed data. Ponding […]

Mineralogy of sodic soils in Ceará

F. O. B. Mota, J. B. Oliveira

01/Dec/1999

Sand, silt and clay fraction mineralogy as well as the weathering processes of two soils with excess of sodium (SPL and SS) were studied in the state of Ceará, Brazil. The sand coarse and silt were studied using polarized microscopy and phase contrast, while the fine silt and clay were analyzed by X-ray diffraction. Additional information on the mineralogical transformations that occurred in the horizons of both pedons was obtained using scanning electron microscopy. The Solodic Planosol showed in the […]

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