Organic cropping systems with input of fresh organic matter can modify the physical and chemical properties of soils and consequently affect their biological composition. The purpose of this study was to determine the effects of juice grape (Vitis labrusca L.) management on the soil chemical and microbial properties of a sandy-textured Oxisol. In October 2006, soil was sampled from two vineyard experiments set up in 2000, and from a neighboring forest area. The following treatments were evaluated in a 2 […]

Knowledge of the soil physical properties, including the clay content, is of utmost importance for agriculture. The behavior of apparently similar soils can differ in intrinsic characteristics determined by different formation processes and nature of the parent material. The purpose of this study was to assess the efficacy of separate or combined pre-treatments, dispersion methods and chemical dispersant agents to determine clay in some soil classes, selected according to their mineralogy. Two Brazilian Oxisols, two Alfisols and one Mollisol with […]

Nitrogen is the main limiting factor in crop productivity and thereby soil management systems may change the mineralization and nitrification rates. In an experiment on soil management systems implemented in 1988 at the experimental station Fundação ABC, Ponta Grossa, in the central South region of the State of Paraná, inorganic N dynamics were examined to find a soil management strategy with a view to a sustainable environment. The objective of this study was to calculate the net mineralization and nitrification […]

Spatial distribution of the saturated hydraulic conductivity (k0) is essential in the study of soil erosion and surface runoff. The purpose of this study was to investigate the spatial continuity of the soil hydrologic characteristic k0 in the watershed Alto Rio Grande, state of Minas Gerais, and to map k0 based on geostatistical procedures, using data without and with logarithmic transformation. Exponential and spherical semi-variogram models were fitted to the experimental semi-variograms in two approaches: ordinary minimum square (MQO) and […]

Nitrification can lead to substantial losses of the applied N through nitrate leaching and N2O emission. The regulation of nitrification may be a strategy to improve fertilizer N recovery and increase its agronomic efficiency. The objective of this study was to evaluate the inhibiting capacity of nitrification in soil by Brachiaria species. The greenhouse experiment was conducted using pots with 10 dm3 of a Red Latosol sample. The treatments consisted of the cultivation of three forage species (Brachiaria brizantha, B. […]

The application of gypsum can make Al unavailable to plants and provide soil nutrients, improving conditions for high crop yields. This study evaluated the chemical characteristics of Red Latosol, with or without exchangeable Al as influenced by gypsum rates (0, 1000, 2000, 3000, 4000, and 5000 kg ha-1) applied to the soil surface, and the effect of gypsum on mineral nutrition and wheat and soybean yields under no-tillage. Gypsum was applied to the surface six months after liming. Six and […]

Fertilizer recommendations in Rio Grande do Sul and Santa Catarina (RS and SC) states are based on studies of crops grown under conventional tillage and knowledge accumulated over the years. In this period, the crop system and soil sampling depth were altered and crop yields increased; this can affect the critical values of K, the fertility status and fertilizer quantity required by crops. This study aimed to determine the levels of available K extracted by Mehlich-1, Mehlich-3 and ion-exchange resin […]

Star fruit (Averrhoa carambola) plants tend to accumulate significant amounts of Mn in their tissues. However, information regarding the form in which the plant stores the excess is scarce. For a deeper understanding of this aspect, star fruit plantlets were grown in nutritive solutions of Furlani (1999) with increasing levels of Mn (0, 0.5, 25 and 50 mg L-1), and after 30, 60, 90 and 120 days the tissues were collected and subjected to a sequence of extracting solutions: water, […]

Barium is an alkaline-earth metal that occurs naturally in soils. It is present in soil in carbonates, sulphates and silicates as well as in the isomorphic substitution of calcium and magnesium in clay minerals. When available at high soil concentrations, Ba is toxic to several living organisms. To rule out the possibility of metal contamination of a particular soil, the natural metal concentrations of this soil must be known. Therefore, the natural soil concentrations of metals must be determined for […]

The Cerrado (Brazilian Savannah) plays an important economic and financial role in the nation, since the pastures of this biome feed cattle for half of the domestic bovine meat productivity, and its agricultural fields produce a third of the country’s grain. The variability and spatial dependence between the soil physical attributes and soybean yield were evaluated in a crop rotation planted on a degraded brachiaria pasture, on a dystroferric Red Latosol of an experimental farm of the State University of […]