Volume 23, Number 4, 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 […]

Inadequate water application is one of the reasons of poor initial plant stand for irrigated maize. This problem is more serious in some soils with superficial crusting after sprinkler irrigation or rainfall. The effect of different water management criteria on maize emergence was evaluated in three soils: Dark-Red Latosol (LE), in Sete Lagoas, and Yellow-Red Latosol (LV) and Alluvial soil, in Janaúba, in Minas Gerais, Brazil. The treatments were based on different strategies for supplying water to soil. A combination […]

The objective of this work was to investigate the effect of increasing closes of Irati lime on the contents of Cu, Fe, Mn and Zn both in soil and the corn plant. Irati lime is a by product obtained by Petrobras Six during the oil shale mining process, presenting high levels of micronutrients. The experiment was conducted in a greenhouse using pots filled with soil from a “Cambisol Tb” A horizon, of a sandy texture. The treatments were arranged in […]

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 […]

The objectives of this study were to determine the influence of different soil tillage methods on the loss of heavy metals by erosion, and to evaluate the level of contamination in sediments and water from the main stream in Caetés watershed, Paty do Alferes County, Rio de Janeiro. The experiment was conducted from December 1996 to March 1997, and cucumber (Cucumis sativus L.) was the cultivated crop. Four Wichmeier plots were installed, with an area of 22 x 4 m. […]

The objective of this work was to determine carbon and nitrogen content in the soil microbial biomass by comparing microwave radiation and chloroform fumigation using the extraction and incubation methods. Two soil samples (Dark-Red Podzolic) were submitted to incubation and extraction after chloroform fumigation and microwave radiation during different periods (2, 5, 10, 15, 20, 30, 40 and 50 min). Two minutes under microwave radiation were sufficient to determine C and N content in the soil biomass using incubation and […]

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 […]

Hydraulic conductivity is one of the most important soil properties for studies dealing with infiltration, water movement within the soil profile and to plant roots and internal drainage. The availability of the function hydraulic conductivity x soil water content (K(θ)) is essential to these studies. However, little is known about the variability of the empirical parameters of this function. Aiming to contribute with information on the variability of these parameters, a study is described in which observations of hydraulic conductivity […]

Nutrient transport towards root surface can be accomplished by mass flow or by mass flow and diffusion, depending on the activity of the nutrient in the soil solution, and on the nutrient demand of the plant. The objective of this greenhouse experiment was to verify the contribution of the mechanisms of mass flow and diffusion for supplying potassium, calcium and magnesium to rice plants. Samples of a clayey Oxysol were treated with Na2CO3, K2CO3, CaCO3 and MgCO3 as amendments. Seventy-five […]

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 […]