Alterations of soil chemical properties by eucalyptus cultivation in five regions in the Rio Doce Valley
01/Jun/2010
Little is currently known about modifications in edaphic characteristics caused by short-rotation eucalyptus and the impacts of these alterations on the sustainability of eucalyptus wood production. This study was carried out to identify theses changes at five sites of eucalyptus plantation in the region of the Rio Doce Valley, state of Minas Gerais, Brazil. Areas with more than three previous eucalyptus cycles, adjacent to pasture land or native forest, were chosen. Soil samples were collected and soil fertility analyzed by […]
Characterization and classification of soils developed from sandstone of the Aquidauana formation
01/Jun/2010
The Aquidauana geological formation consists of a set of up to 500 m thick sediments predominantly composed of sandstone with fine to medium grain size, interspersed with sandy conglomerates. In this environment, the topography is one of the main conditioning factors of the formation of different soil types in the landscape. The objective of this study was to characterize and classify soils developed from these sandstones. Four soils profiles along a representative toposequence of gentle slopes were sampled and studied. The […]
Microbial and enzymatic activity in soil after organic composting
01/Jun/2010
Microbial activity and biochemical properties are important indicators of the impact of organic composting on soil. The objective of this study was to evaluate some indicators of soil microbial and biochemical processes after application of compost (household waste). A Typic Acrustox, sampled at a depth of 10 cm under Cerrado biome vegetation, was evaluated in three treatments: control (soil without organic compost amendment) and soil with two doses of domestic organic compost (10 and 20 g kg-1 soil). The following properties were evaluated: […]
Occurrence of silica bodies in surface horizons of soils in different ecosystems
01/Jun/2010
The understanding of the processes that cause the varied distribution of silica bodies in soils is essential for the interpretation of the possible environmental factors related to their stability, sediment deposition, paleosol formation and for the analysis of archaeological sites. Thus, this study had the objective of identifying and characterizing the silica bodies morphology from surface soil horizons collected at different terrestrial ecosystems. Samples of surface horizons were collected from 10 soil profiles and heated in a muffle furnace to […]
Influence of soil management on chemical and physical soil properties along a toposequence in the Araguaia river basin, State of Tocantins
01/Apr/2010
The conversion of native vegetation into agricultural areas can modify soil organic matter content and decomposition and synthesis processes and therefore the nutrient avalilability. The aim of this study was to evaluate the chemical and physical soil properties (0-15 cm depth) in a toposequence characterized by planted pasture beside the native Cerrado vegetation cover. The study was carried out in Colméia, State of Tocantins. Ten sampling points were determined (five samples in native vegetation and five samples in pasture) for […]
Bermuda grass sod production as related to nitrogen rates
01/Apr/2010
Of all nutrients, N has the strongest effect on grass growth and an adequate N fertilization can reduce the time required for the formation of high-quality mats. This study aimed to evaluate the influence of N fertilization on Bermuda grass sod production and quality. The experiment was conducted in an area of commercial sod production, in Capela do Alto, state of São Paulo. Cynodon dactylon (Pers) L., known as Bermuda grass, was evaluated in a randomized complete block design with […]
Evaluation of atrazine transport in soils under different agricultural managements
01/Apr/2010
The scarcity of information on pesticide transport in tropical soils under no-tillage is disproportional to the relevance of knowledge in the evaluation of the risk of soil and ground water contamination. The experiments simulated strong rains with continuous water flow using a new method for simultaneous advection, diffusion and sorption measurement, representing pesticide transport along the different studied soil layers. Results showed no correlation between soil permeability and atrazine leaching. The ten times higher permeability in no-tillage (NT) and natural […]
Macronutrient uptake of sunflower (Helianthus annuus L.)
01/Apr/2010
This study aimed to establish curves of macronutrient accumulation in sunflower. The experiment was conducted in the field on a Typic Hapludox, at the experimental station of Embrapa Soja in Londrina, State of Paraná. The plots consisted of 14 25 m long rows spaced 0.70 m apart, resulting in a total area of 245 m2, with four replications. Prior to sowing a fertilization seeding of 300 kg ha-1 of 05-20-20 NPK fertilizer was applied. Fertilization was split in two applications […]
Gypsum in management systems and soybean productivity in southwest region of Goiás
01/Apr/2010
The tilling of areas in no-tillage to several years and the use of gypsum practices are observed among the farmers in southwestern Goiás. This study was carried out to evaluate the effect of gypsum rates (0, 1, 2, 4 e 6 Mg ha-1) on some chemical attributes in the soil’s depth and in soybean yield in area under long-term no-till, with and without tillage. A complete randomized block scheme with a split-split-plot design with four replicates was used. The area […]
Nitrate and ammonium in soil solution in tobacco management systems
01/Apr/2010
Tobacco farmers of southern Brazil use high levels of fertilizers, without considering soil and environmental attributes, posing great risk to water resources degradation. The objective of this study was to monitor nitrate and ammonium concentrations in the soil solution of an Entisol in and below the root zone of tobacco under conventional tillage (CT), minimum tillage (MT) and no-tillage (NT). The study was conducted in the small-watershed Arroio Lino, in Agudo, State of Rio Grande do Sul, Brazil. A base […]