Volume 27, Number 1, 2003

The objective of this study was to evaluate the reactivity of four Si sources: schist, two types of slag and a thermal-phosphate based on Si availability in the Typic Eutrustults and in the tomato crop uptake. Two experiments were carried out in a randomized block design with the following treatments: check plot, 6 t ha-1 of schist, 6 t ha-1 of Mannesman slag, 6 t ha-1 of Dedini slag and 2.5 t ha-1 of thermal-phosphate. The Si content (SiO2 total) […]

The objective of monitoring the adequate nitrogen (N) content in maize is to determine when a nutrient application becomes necessary, since the use of high doses of this nutrient may contaminate superficial and underground waters with nitrate. This experiment was conducted to evaluate the chlorophyll content in leaves, measured by a chlorophyll meter, as an indicator of the N level in maize, at four growth stages, in the state of Rio Grande do Sul, Brazil, during the growing season 1999/2000. […]

Lime application on the soil surface in no-tillage systems, without incorporation, has not been effective in certain edaphic and climatic conditions for the correction of acidity or for calcium and magnesium supply to plants. Searching alternatives for limestone application without the conventional tilling and harrowing operations, this study tried to evaluate the efficiency of different lime application forms for the chemical soil attributes, nutritional state, and agronomic characteristics of corn crop. A randomized block design with split-plots and three replications […]

This study was conducted at the Experimental Station of the Faculdade de Engenharia (UNESP), Ilha Solteira County, Mato Grosso do Sul State, Brazil, with the aim of evaluating chemical modifications in a Red Latosol under cerrado, subjected to different use and management systems. A completely randomized design with six treatments and 10 replications was used. The treatments of use and management were: no-tillage with annual crops, conventional system with annual crops, minimum tillage with annual crops, native vegetation (cerrado), pasture, […]

Site-specific regression coefficient values are essential for erosion prediction with empirical models. With the objective to investigate the surface-soilconsolidation factor, Cf, linked to the RUSLE’s prior-land-use subfactor, PLU, an erosion experiment using simulated rainfall on a 0.075 m m-1 slope, sandy loam Paleudult soil, was conducted at the Agriculture Experimental Station of the Federal University of Rio Grande do Sul (EEA/UFRGS), in Eldorado do Sul, State of Rio Grande do Sul, Brazil. Firstly, a row-cropped area was excluded from cultivation […]

Erosion is deleterious because it reduces the soil’s productivity capacity for growing crops and causes sedimentation and water pollution problems. Surface and buried crop residue, as well as live and dead plant roots, play an important role in erosion control. An efficient way to assess the effectiveness of such materials in erosion reduction is by means of decomposition constants as used within the Revised Universal Soil Loss Equation – RUSLE’s prior-land-use subfactor – PLU. This was investigated using simulated rainfall […]

The analysis of Brazilian commercial FTE fertilizers was the objective of this study, under application of routine laboratory methods used for the analysis of non-FTE fertilizers. Cd, Ni, and Pb contents were also determined. The methods proved to be adequate for the analysis of FTE fertilizers. This indicates that FTE fertilizers on the Brazilian market are not really FTE fertilizers; that is, they are not silicates founded with micronutrients. Uncontrolled contents of metal micronutrients in the products, as well as […]

Sewage sludges are nutrient-rich organic materials, thus presenting potential for agricultural use. The use of these materials, however, can be limited by the presence of heavy metals in their composition. This study tried to evaluate: (a) the solubility of Cd, Pb and Zn in soils treated with sewage sludge enriched with these metals; (b) the incubation time effect on distribution changes of Cd, Pb and Zn in their different chemical forms in two soils treated with sewage sludge enriched with […]

The aim of this study was to evaluate the dissipation, effects on microorganisms, and sorption/desorption of 14C-diclosulam in Rhodic Hapludox soil samples, cultivated for 10 years under no-till (NT) or conventional tillage (CT) systems. We carried out three individual experiments. In the dissipation and sorption/desorption experiments, diclosulam was applied to soil samples of both management systems. The microbial activity experiment tested diclosulam application and non-application on the soil samples. The degradation experiment was carried out in Bartha flasks, weekly evaluating […]

To evaluate the effect of different soil tillage methods on heavy metal accumulation in soil and edible bean plants (Phaseolus vulgaris L.), a study was carried out in the county of Paty do Alferes, Rio de Janeiro State, Brazil, on a Red-Yellow Latosol with 30 % slope. On 22,0 x 4,0 m Wischmeier plots, the following methods were installed: conventional tillage: downhill furrows and burning of vegetal residues (PC); tillage along contour lines: contour plowing by animal traction with strips […]