Minimum number of tension measurements to determine the soil-water retention curve of a eutrophic red oxisoil under no-tillage
01/Dec/2010
The soil-water retention curve (SWRC) is essential to understand the physical-hydric soil behavior. However, data for the construction of the SWRC are obtained in slow and expensive processes. This study hypothesized the possibility that SWRC could be constructed based on fewer tension data within a shorter time, without affecting the accuracy. The objective was to determine the tension data required for the construction of an accurate SWRC in less time. Undisturbed soil samples were collected from a Eutrophic Red Oxisol […]
Morphology of soil-saprolite-rock contacts in neossolos derived from sandstone (caturrita formation) in Rio Grande do Sul, Brazil
01/Dec/2010
The use of the shallow Neossolos (Leptosols and Regosols) is limited in view of the small depth and rock fragments on the surface. There is a lack of information about the definition of the contacts between soil, saprolite and rock in this soil class, as well as tools that would facilitate the morphologic field identification. The objectives of this research were an evaluation of the morphology of the contact between soil, saprolite and rock in the Neossolos derived from the […]
Cation dynamics in soils with different salinity levels growing irrigated rice
01/Dec/2010
Salinity levels in soils of the Outer Coastal Plain of Rio Grande do Sul, Brazil, can be high, due to excess of Na in the irrigation water, evapotranspiration and soil development from marine sediments. The cultivation of irrigated rice could be an alternative, since ion uptake as well as leaching by the establishment of a water layer could mitigate the effects of soil salinity. This study aimed to evaluate the dynamics of basic cations in the solution of Albaqualf soils […]
Copper availabity for eucalyptus seedlings in cerrado soils
01/Dec/2010
In Brazil, along with the intensification of clonal forestry, the management of more productive and more nutrient-demanding genotypes has led to the appearance of micronutrient deficiency symptoms, mainly of Boron, and more recently, of Copper (Cu) and Zinc, especially in Cerrado areas. The purpose of this study was to evaluate three extractant solutions to determine Cu availability (Mehlich-1, Mehlich-3 and DTPA pH 7.3) for eucalyptus seedlings grown under greenhouse conditions in six Cerrado soil samples and to assess the influence of […]
Nitrogen washing from C3 and C4 cover grasses residues by rain
01/Dec/2010
Crop species with the C4 photosynthetic pathway are more efficient in assimilating N than C3 plants, which results in different N amounts prone to be washed from its straw by rain water. Such differences may affect N recycling in agricultural systems where these species are grown as cover crops. In this experiment, phytomass production and N leaching from the straw of grasses with different photosynthetic pathways were studied in response to N application. Pearl millet (Pennisetum glaucum) and congo grass […]
Temporal stability of soil moisture under three soil uses in a catchment of the Mantiqueira Range region, Minas Gerais State, Brazil
01/Dec/2010
The description of soil hydrological processes is relatively complex, especially in the case of moisture, which is influenced by edaphic, topographic, climatic and vegetation factors. Under field conditions, an adequate sampling strategy is required to estimate soil moisture, considering variations in time and space. To represent the soil moisture adequately with less sampling effort and cost, the concept of temporal stability has often been applied. This study was carried out with the objective of analyzing the temporal stability of the […]
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 […]