Nowadays no-tillage soybean is widely used in crop-livestock farming systems in Brazil. The yield of no-tillage soybean was analysed in the county of Selvíria (latitudes from 20 ° 18 ‘ 05 ” S and 20 ° 18 ‘ 28 ” S and the longitudes de 52 ° 39 ‘ 02 ” W and 52 ° 40 ‘ 28 ” W (Mato Grosso do Sul State – Brazil), in the 2006/07 growing season, as affected by some physical properties of a local Typic Acrustox. The objective was to determine the soil property that could best explain the variability in the agricultural productivity. For this purpose, […]

The use of water for rice irrigation in Rio Grande do Sul, Brazil, where the water courses are connected with the sea, may cause salt accumulation in the soil at harmful levels for the establishment of rice plants in the following years, especially when high rates of potassium fertilizer are applied in the plant rows. The study was carried out with the purpose of evaluating the effect of potassium chloride management on the establishment and absorption of cations by rice […]

The accuracy of mechanical analysis depends on the complete dispersion and stability of the soil suspension in order to make the separation of the soil fractions possible. The purpose of this study was to evaluate the efficacy of adding sand in different amounts and particle sizes in the dispersion phase of the soil textural analysis in attempt to improve the accuracy of results. The soils used were Rhodic Eutrudox (oxidic) (LVef), Anionic Rhodic Acrudox (LVwf), Rhodic Eutrudox (kaolinitic) (LVe), Arenic […]

The deleterious effects of both Mn deficiency and excess on the development of plants have been evaluated with regard to aspects of shoot anatomy, ultrastructure and biochemistry, focusing mainly on the manifestation of visual symptoms. However, there is little information in the literature on changes in the root system in response to Mn supply. The objective of this study was to evaluate the effects of Mn doses (0.5, 2.0 and 200.0  μmol L-1) in a nutrient solution on the anatomy of […]

The establishment of irrigation management has been based on the soil water potential (Ψ) as a limiting factor for plant growth. However, other variables can affect crop growth even when Ψ is not limiting. The least limiting water range (LLWR) is a concept of available water that take account the influence of aeration and soil resistance to penetration (SR) in addition to Ψ. The objective of this study was to quantify the LLWR in an irrigated Dystroferric Red Nitosol and […]

The decontamination of soils and substrates contaminated with arsenic through phytoremediation techniques has attracted increasing interest of researchers and specialists of environmental sciences. This study aimed to evaluate the potential of the species townsville stylo (Stylosanthes humilis HBK), forage peanut (Arachis pintoi Krapov. & Gregory), oat (Avena strigosa Schreb), and ryegrass (Lolium multiflorum Lam.) for phytoremediation of arsenic-contaminated soils. Samples of a Red Yellowh Latossol (Oxisol) were incubated with different doses of arsenic (0; 50; 100 and 200 mg dm-3). After this […]

Nitrate reductase is the first enzyme in the pathway of nitrate reduction by plants, followed by glutamine synthetase, which incorporates ammonia to glutamine. The purpose of this study was to evaluate the nitrate reductase and glutamine synthetase activity, total soluble protein content, N and Ni content in coffee leaves during fruit development under field conditions to establish new informations to help assess the N nutritional status and fertilizer management. The experimental design was in randomized complete blocks, arranged in a […]

As an alternative land use of savanna areas in Roraima, commercial forest stands of Acacia mangium are being increasingly implemented. The purpose of this study was the in situ determination of soil and water losses in commercial stands of Acacia mangium and compare them with those under native savanna. The experiment was conducted on a Red-Yellow Argisol (Ultisol) in the region of Serra da Lua where Gerlach sediment and water collectors were installed. Soil density, texture, penetration resistance and infiltration […]

The impact of charcoal production on soil hydraulic properties, runoff response and erosion susceptibility were studied in both field and simulation experiments. Core and composite samples, from 12 randomly selected sites within the catchment of Kotokosu were taken from the 0-10 cm layer of a charcoal site soil (CSS) and adjacent field soils (AFS). These samples were used to determine saturated hydraulic conductivity (Ksat), bulk density, total porosity, soil texture and color. Infiltration, surface albedo and soil surface temperature were also […]

The tensiometer is the most used instrument in the field to determine the soil water matric potential, so that the evaluation of its reading systems is very important. The purpose of this study was to evaluate different reading systems for the traditional field tensiometer traditional field tensiometer and it is justified because it will indicate the situation in which each system should be used. The experiment was carried out in a completely randomized factorial design (3 x 2 x 2 x 11), using three tensiometer reading […]