Soil chemical atributes associated with wheat yield in a plot with different yield potentials
01/Aug/2014
Different yield potentials between plots and within them have been verified in areas managed under no-till (NT). Precision farming (PF) techniques can help in identifying these distinct areas, but for efficient soil fertility management in areas under long-term NT, there must be representative sampling. The aim of this study was to evaluate the influence of soil chemical properties on wheat yield in accordance with the sampling layer or depth in an area under long-term NT using zones of a plot […]
Characterization and classification of soils with dark subsurface horizons derived from granite rocks in the Sul-Rio-Grandense Shield, Brazil
01/Aug/2014
Dark subsurface horizons with morphological characteristics similar to sombric horizons are found in higher altitude areas of the eastern portion of the Sul-Rio-Grandense Shield, Brazil. They developed in the A2, AB (or AC), and BA horizons of Ultisols, Alfisols, and Entisols. The mechanisms responsible for their genesis are still poorly understood, although most authors agree on the illuvial origin of the humus horizon and on its diagnostic character. The objective of this study was to characterize and analyze nine soil […]
Response of one-, five-, and nine-year-old pinus taeda to NPK fertilization in southern Brazil
01/Aug/2014
In the southern highland (Planalto Sul) region of Santa Catarina, Brazil, most of the pine forests were planted without soil fertilization. Currently, many areas are in the second or third rotation, and their productivity may be limited by low soil fertility. An alternative to mitigate this problem would be fertilization in the established forest. This study was carried out with the objective of evaluating the effect of fertilization with N, P, and K at different growth stages of Pinus taeda. […]
The effects of land use and soil management on the physical properties of an Oxisol in Southeast Brazil
01/Aug/2014
Soils of the tropics are prone to a decrease in quality after conversion from native forest (FO) to a conventional tillage system (CT). However, the adoption of no-tillage (NT) and complex crop rotations may improve soil structural quality. Thus, the aim of this study was to evaluate the physical properties of an Oxisol under FO, CT, and three summer crop sequences in NT: continuous corn (NTcc), continuous soybean (NTcs), and a soybean/corn rotation (NTscr). Both NT and CT decreased soil […]
Ammonia volatilization and yield components after application of polymer-coated urea to maize
01/Aug/2014
A form of increasing the efficiency of N fertilizer is by coating urea with polymers to reduce ammonia volatilization. The aim of this study was to evaluate the effect of polymer-coated urea on the control of ammonia volatilization, yield and nutritional characteristics of maize. The experiment was carried out during one maize growing cycle in 2009/10 on a Geric Ferralsol, inUberlândia, MG, Brazil. Nitrogen fertilizers were applied as topdressing on the soil surface in the following urea treatments: polymer-coated urea […]
Variability of root traits in common bean genotypes at different levels of phosphorus supply and ontogenetic stages
01/Aug/2014
Selection of common bean (Phaseolus vulgaris L.) cultivars with enhanced root growth would be a strategy for increasing P uptake and grain yield in tropical soils, but the strong plasticity of root traits may compromise their inclusion in breeding programs. The aim of this study was to evaluate the magnitude of the genotypic variability of root traits in common bean plants at two ontogenetic stages and two soil P levels. Twenty-four common bean genotypes, comprising the four growth habits that […]
Influence of the grazing height of ryegrass and oat on the physical properties of an Oxisol after seven years of crop-livestock system
01/Aug/2014
The pressure applied by animal hooves can lead to soil surface compaction in a crop-livestock system (CLIS), with effects on soil physical quality. The hypothesis of this study was that the trampling of animals as a result of grazing on oat and ryegrass crops in a Latossolo Vermelho distroférrico (Oxisol) under no-tillage in a CLIS degrades soil physical quality. The aim of this study was to evaluate the effect of different grazing heights on soil bulk density (BD), total porosity […]
Three-dimensional interpolation of soil data: fertility and pedomorphological features in southern Brazil
01/Aug/2014
The graphical representation of spatial soil properties in a digital environment is complex because it requires a conversion of data collected in a discrete form onto a continuous surface. The objective of this study was to apply three-dimension techniques of interpolation and visualization on soil texture and fertility properties and establish relationships with pedogenetic factors and processes in a slope area. The GRASS Geographic Information System was used to generate three-dimensional models and ParaView software to visualize soil volumes. Samples […]
Analysis of NPK fertilizers inspected by mapa from 2008 to 2010
01/Aug/2014
Brazil is the fourth largest consumer of fertilizers in the world. Among these, bulk blends fertilizers are the most consumed in the country. After updating of Brazilian legislation in regard to fertilizers in 2004, many producers claim that there was an excessive increase in the strictness of legislation concerning inspection of nutrient levels in those products. Within this context, the objective of this study was to provide an exploratory and descriptive statistical analysis to the data gathered by MAPA (Ministry […]
Impacts of deforestation on water balance components of a watershed on the Brazilian East Coast
01/Aug/2014
The Brazilian East coast was intensely affected by deforestation, which drastically cut back the original biome. The possible impacts of this process on water resources are still unknown. The purpose of this study was an evaluation of the impacts of deforestation on the main water balance components of the Galo creek watershed, in the State of Espírito Santo, on the East coast of Brazil. Considering the real conditions of the watershed, the SWAT model was calibrated with data from 1997 […]
