Volume 39, Number 2, 2015

Studying nutrient uptake and dry matter accumulation in plants as affected by crop developmental stages is essential to establish and assist strategies for crop fertilization. The aim of this study was to assess shoot dry matter and macronutrient accumulation in Guizotia abyssinica (niger) at different growth and development stages. A randomized block experimental design with five replications was used. Shoot samples of the plants were taken at 15, 30, 45, 60, 75, and 90 days after seedling emergence (DAE). At […]

Farmers must carefully choose the cultivar to be grown for a successful carrot crop. The yield potential of the cultivar may influence nutrient demand and should be known to plan for fertilization application. The aim of this study was to evaluate the cultivar effect on carrot yield and on the nutrient content and quantities allocated to leaves and roots. Three experiments were set up in two crop seasons in Rio Paranaíba, MG, Brazil. In the first season, typical summer, 10 […]

Alternative copper (Cu) sources could be used in fertilizer production, although the bioavailability of copper in these materials is unknown. The objective of this study was to evaluate the extractants neutral ammonium citrate (NAC), 2 % citric acid, 1 % acetic acid, 10 % HCl, 10 % H2SO4, buffer solution pH 6.0, DTPA, EDTA, water, and hot water in the quantification of available Cu content in several sources, relating them to the relative agronomic efficiency (RAE) of wheat grown in […]

In quantifying the least limiting water range (LLWR), different critical limits of resistance to penetration (RP) and moisture at field capacity (θFC) are generally used. For agricultural soils, these values are documented in the literature. However, for constructed soil after coal mining, there is a large information gap. The aim of this study was to quantify the least limiting water range of a constructed soil under different cover crops in a coal mining area in Candiota, RS (Southern Brazil), considering […]

Infiltration is the passage of water through the soil surface, influenced by the soil type and cultivation and by the soil roughness, surface cover and water content. Infiltration absorbs most of the rainwater and is therefore crucial for planning mechanical conservation practices to manage runoff. This study determined water infiltration in two soil types under different types of management and cultivation, with simulated rainfall of varying intensity and duration applied at different times, and to adjust the empirical model of […]

Assessing the quality of agricultural soils is important for defining and adopting management practices that ensure socioeconomic and environmental sustainability. The methods for indexation of quality indicators called the Integrated Quality Index (IQI) and the Nemoro Quality Index (NQI) were used in this study to evaluate soil quality in experimental plots planted to eucalyptus. The selection of these indicators was made based on nine soil quality indicators: geometric mean diameter, water permeability, organic matter, macro- and microporosity, total porosity, bulk […]

Understanding the agricultural potential of a soil is often based only on interpretation by univariate analyses, and this may increase the scale of the problems when selecting appropriate soil management practices. Thus, multivariate analysis is an alternative since it is a set of procedures aimed at grouping individuals and discriminating between these groups. It also serves as an instrument for selection of variables in that those with the highest weight in the construction of the first principal components are likely […]

Agricultural management affects soil structure, modifying soil physical properties and soil water movement. The objective of this study was to evaluate the effects of no-tillage (NT) and conventional tillage (CT) on soil structure through physical properties and pore distribution in 2-D digital images. The study was conducted in an Oxisol with a randomized block design. Soil bulk density, soil macroporosity, mean weighted diameter (MWD), saturated hydraulic conductivity (SHC), and analysis of 2-D digital images (156.25 μm2 resolution) were evaluated at […]

Soil quality (SQ) assessment is an important strategy for defining management practices and systems capable of maintaining and/or improving the sustainability of agricultural systems. Thus, the aim of this study was to evaluate changes in SQ by physical, chemical, and biological indicators in an Oxisol under different tillage systems and fertilizer sources. The study was conducted in Taquaruçu do Sul, RS, Brazil based on an experiment set up in 2009 in a randomized block design with four replications. The treatments […]

Sediments were removed from the Belem River, and their uncertain destination may cause environmental damage and additional costs to the municipality. The aim of this study was to simulate the possibility of using an alternative allocation of the sediments based on Brazilian environmental law. The evaluation of destination and/or use was made from a preliminary chemical evaluation of inorganic contaminants (Cd, Pb, Cu, Cr, Ni, Ag, and Zn) and polycyclic aromatic hydrocarbons (PAHs) related to productive activities in the region. […]