3290 results

Effect of cropping systems in no-till farming on the quality of a Brazilian Oxisol

Getulio de Freitas Seben Junior, José Eduardo Corá, Rattan Lal

01/Aug/2014

The no-till system with complex cropping sequences may improve the structural quality and carbon (C) sequestration in soils of the tropics. Thus, the objective of this study was to evaluate the effects of cropping sequences after eight years under the no-till system on the physical properties and C sequestration in an Oxisol in the municipality of Jaboticabal, Sao Paulo, Brazil. A randomized split-block design with three replications was used. The treatments were combinations of three summer cropping sequences – corn/corn […]

Changes in a Rhodic Hapludox under no-tillage and urban waste compost in the northwest of Rio Grande do Sul, Brazil

Moacir Tuzzin de Moraes, Vanderlei Rodrigues da Silva, Maurício Roberto Cherubin, Reimar Carlesso, Henrique Debiasi, Renato Levien

01/Aug/2014

The use of urban waste compost as nutrient source in agriculture has been a subject of investigation in Brazil and elsewhere, although the effects on soil physical and chemical properties and processes are still poorly known. The aim of this study was to evaluate the effect of application of urban waste compost and mineral fertilizer on soil aggregate stability and organic carbon and total nitrogen content of a Rhodic Hapludox under no-tillage in the northwestern region of Rio Grande do […]

Soil chemical atributes associated with wheat yield in a plot with different yield potentials

Luiz Fernando Machado Kramer, Marcelo Marques Lopes Müller, Cassio Antônio Tormena, Aline Marques Genú, Leandro Michalovicz, Marcelo Vicensi

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

Márcio Ramos Botelho, Luiz Fernando Spinelli Pinto, Ana Cláudia Rodrigues de Lima, Márcio Renato Nunes

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

Letícia Moro, Luciano Colpo Gatiboni, Marcia Aparecida Simonete, Paulo Cezar Cassol, Djalma Miler Chaves

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

Getulio de Freitas Seben Junior, José Eduardo Corá, Rattan Lal

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

Eduardo Zavaschi, Letícia de Abreu Faria, Godofredo Cesar Vitti, Carlos Antonio da Costa Nascimento, Thiago Augusto de Moura, Diego Wyllyam do Vale, [...]

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

Roberto dos Santos Trindade, Adelson Paulo Araújo

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

Wagner Henrique Moreira, Cássio Antonio Tormena, Edner Betioli Junior, Leonardo Pim Petean, Sérgio José Alves

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

Tales de Campos Piedade, Vander de Freitas Melo, Luiz Cláudio de Paula Souza, Jeferson Dieckow

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 […]

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