Morphostructural characterization of soil conventionally tilled with mechanized and animal traction with and without cover crop
01/Dec/2010
The structural stability and restructuring ability of a soil are related to the methods of crop management and soil preparation. A recommended strategy to reduce the effects of soil preparation is to use crop rotation and cover crops that help conserve and restore the soil structure. The aim of this study was to evaluate and quantify the homogeneous morphological units in soil under conventional mechanized tillage and animal traction, as well as to assess the effect on the soil structure […]
Pedochronology and development of peat bog in the environmental protection area pau-de-fruta – Diamantina, Brazil
01/Dec/2010
In the region of the Serra do Espinhaço Meridional, peat bog is formed in hydromorphic environments developed in sunken areas on the plain surfaces with vegetation adapted to hydromorphic conditions, favoring the accumulation and preservation of organic matter. This pedoenvironment is developed on the regionally predominant quartzite rocks. Peat bog in the Environmental Protection Area – APA Pau-de-Fruta, located in the watershed of Córrego das Pedras, Diamantina,Brazil, was mapped and three representative profiles were morphologically characterized and sampled for physical, […]
Uncertainty in erosion prediction with usle: impacts and mitigation
01/Dec/2010
Despite the significance uncertainty in the variables of erosion prediction models, spatial and temporal variability is seldom considered in soil conservation analyses and planning. The consequences of this simplification are misleading soil loss predictions, with consequences for the agricultural and environmental sustainability of agricultural fields. The objective of this paper was (a) to estimate the effect of spatial and temporal variability of the USLE factors on erosion prediction of a homogeneous agricultural field, in the Distrito Federal (Brazil), (b) to […]
Barium, cadmium, chromium and lead in maize plants and in an oxisol after eleven years of sewage sludge applications
01/Dec/2010
The presence of heavy metals in sewage sludge is one of the greatest restrictions to its application in agricultural areas. This study aimed to evaluate the effects of application rates of sewage sludge of 11 consecutive years on the distribution of Ba, Cd, Cr and Pb in three layers (0-10, 10-20 and 20-40 cm) of a Typic Hapludox soil, as well as to quantify these metals in maize leaf and kernels. The experiment was conducted under field conditions, using a randomized […]
Tillage systems and nutrient sources affecting soil cover, temperature and moisture in a clayey oxisol under corn
01/Dec/2010
Tillage affects soil physical properties, e.g., porosity, and leads to different amounts of mulch on the soil surface. Consequently, tillage is related to the soil temperature and moisture regime. Soil cover, temperature and moisture were measured under corn (Zea mays) in the tenth year of five tillage systems (NT = no-tillage; CP = chisel plow and single secondary disking; CT = primary and double secondary disking; CTb = CT with crop residues burned; and CTr = CT with crop residues […]
Manganese uptake and redistribution in soybean as affected by glyphosate
01/Dec/2010
Detrimental effects of glyphosate on plant mineral nutrition have been reported in the literature, particularly on Mn uptake and redistribution. However, in most of the experiments conducted so far glyphosate-susceptible plants were used. Effects of glyphosate on Mn absorption kinetics, accumulation, and distribution within the plant, as well as soybean response to Mn as affected by glyphosate were studied in three experiments. In the first experiment, in nutrient solution, the effect of glyphosate on soybean Mn uptake kinetic parameters (Imax, […]
In-furrow inoculation with Bradyrhizobium alternatively to seed inoculation of soybean
01/Dec/2010
Biological N fixation in soybean is indispensable in Brazil, sparing the use of mineral N and reducing crop production costs. The objective of this study was to compare in-furrow inoculation of soybean with Bradyrhizobium to the traditional practice of seed inoculation, in an experiment performed in a soil with low organic matter content and without soybean-nodulating rhizobia. A field experiment was carried out in the Cerrado of Roraima in 2006 and repeated in 2007, with the treatments: (1) control (no […]
Agronomic performance of phosphate fertilizers in an oxisol under no-tillage
01/Dec/2010
Little is known about the agronomic effectiveness of phosphate rocks in high-yielding crop rotation systems under no-till in the Center-South of the state of Paraná, Brazil. This field study was undertaken to compare the effectiveness of rock phosphates and soluble P fertilizers to increase the yield of several annual crops grown in two consecutive triennial crop-rotation cycles under no-tillage. The experiment was carried out in an Oxisol, in Guarapuava, PR, from 2000 until 2006. Two phosphate rocks (PR – Gafsa […]
Mobility of P, Cu and Zn in soil columns under no-till and organic and mineral fertilization
01/Dec/2010
The retention of mineral elements applied to the soil surface is crucial to maintain water quality. The objective of this study was to evaluate the effect of liquid swine manure and mineral fertilizer on leaching of P, Cu and Zn through undisturbed soil columns (height 25 cm, diameter 20.3 cm) of an Oxisol under no tillage. A water volume (10.020 cm3) corresponding to three times soil total pore volume (3,340 cm3) was continuously applied to the columns, and the sampling and analysis of the […]
Reference quality values for heavy metals in soils from Espírito Santo State, Brazil
01/Dec/2010
The Reference Quality Values (RQV) for heavy metals in soils are quite heterogeneous around the world. In Brazil, few studies establishing such values have been published. In the absence of VRQ of heavy metals in soils established for the specific conditions of the State of Espírito Santo, international generic values or values developed for other States are used. However, it should be noted that the use of these values can lead to erroneous assessments, due to the regional differences in […]
