3312 results

Cation mobility and acidity decrease in a Haplumbrept due to surface liming combined with potassium fertilizers

Lisandra Pinto Della Flora, Paulo Roberto Ernani, Paulo Cesar Cassol

01/Dec/2007

The low reactivity of lime below the application layer is mainly due to its low solubility, to the increase in soil negative charge in the applied zones, and to the short permanence of anions of added anions in the soil solution. This study was carried out to evaluate the effect of anions added as potassium salts on increasing the reactivity of surface-applied limestone. The experiment was carried out in 2005 on a Haplumbrept (360 g kg-1 clay, 60 g kg-1 organic matter, and […]

Hydro-physical properties of an Oxisol under different management systems

Márcio Luis Vieira, Vilson Antonio Klein

01/Dec/2007

Chiseling is one of the mechanical practices that can be used in no-tillage (NT) soils in order to reduce soil bulk density, resistance to root penetration, and to increase water permeability. The effect of these changes on plant growth and consequently on grain yield depends on climatic conditions. In soils with ideal moisture conditions, the physical limitations tend to be less noticeable. This study aimed to analyze the changes in the physical and hydric properties of a chiseled Oxisol under […]

Content and maximum capacity of arsenic adsorption in Brazilian Oxisols

Mari Lucia Campos, Luiz Roberto Guimarães Guilherme, Rafael Siqueira Lopes, Alessandra Silveira Antunes, João José Granate de Sá e Melo Marques, Nilton Curi

01/Dec/2007

In view of the toxicity of As for man and animals and the possibility of existence of a great number of contaminated areas it is imperative to know the total As content in soils considered uncontaminated and about As sorption processes in soils of variable charge. The objective of this work was to determine the total content and maximum capacity of As adsorption (CMADSAs) in Oxisols. The total content was determined by the USEPA 3051A method. The cmADSAs was determined by […]

Phosphorus forms in soils under influence of liming and organic fertilization

Renato Ferreira de Souza, Valdemar Faquin, Alex Teixeira de Andrade, Paulo Rogério Ferreira Torres

01/Dec/2007

The distribution of phosphorus forms in the different soil compartments (labile, little labile and non-labile) is very influenced by geochemical and biological processes and by human activities. To evaluate the effect of liming and cattle manure on soil phosphorus forms, four experiments were carried out in an entirely randomized design, in a 4 x 5 factorial layout with four repetions, in a greenhouse. The treatments consisted of four liming levels (0; 0.5; 1 and 2 times the recommended dose to reach V […]

Spatial and temporal evaluation of gravimetric and volumetric water storage in an Oxisol under citrus

Dolorice Moreti, Paulo Leonel Libardi, Genelício Crusoé Rocha, Márcio José Lovatti, Laura Ianello Giassetti Aguiar

01/Dec/2007

Temporal stability is described as the temporal persistence of a spatial pattern and is evaluated through correlation analysis of successive measurement data. In this study, the soil water storage was evaluated along two 76 m transects, each of them sampled at 20 points. The soil is an Oxisol (Yellow Red Latosol) under an 11- year-old citrus orchard, in Piracicaba-SP, Brazil. Soil water content, for the calculation of soil water storage in the layer 0.0-1.10 m, was obtained from weekly neutron probe readings at […]

Determination of the subsurface quality index in a Cohesive Argisolic Yellow Latosol under natural forest in Coastal Plains

José Fernandes de Melo Filho, André Leonardo Vasconcelos Souza, Luciano da Silva Souza

01/Dec/2007

Soil is an essential natural resource for life. Its overall capacity to function as substratum for plants, as environmental filter and regulator of gas, water and energy flow is defined as soil quality. An soil quality index can be used to monitor the effects of agricultural use on the soil attributes. The objective of this study was to determine a soil quality index (SQI) for the subsurface horizons of a cohesive argisolic Yellow Latosol (LAx) of Coastal Plains under natural […]

Contribution of clay fraction minerals of subtropical soils to the specific surface area and cation exchange capacity

Ivan Granemann de Souza Junior, Antonio Carlos Saraiva da Costa, José Alexandre Sambatti, Wilson Sacchi Peternele, Cássio Antonio Tormena, Célia Regina Montes, [...]

01/Dec/2007

The specific surface area (SSA) is related to several properties that define the soil physico-chemical behavior. In this research, 23 soil samples developed from different parent materials found in the southern Brazil were used. They were evaluated for the contribution of the main soil constituents to the effective cation exchange capacity (CECe) and SSA. The clay fraction minerals were identified by X ray diffraction (XRD) and quantified by thermal analysis; the CECe, the SSAt (total) by the ethylene glycol monoethyl […]

Planning the sampling for preconsolidation pressure of a red latosol

Ivoney Gontijo, Moacir de Souza Dias Junior, Marcelo Silva de Oliveira, Cezar Francisco Araujo Junior, Bruno Silva Pires, Carloeme Alves de Oliveira

01/Dec/2007

Preconsolidation pressure is currently used as a tool in the study of the soil compaction process. The purpose of this work was to determine the layout and number of samples required for the determination of the preconsolidation pressure (sp) in a Red Latosol, as well as to characterize its variability and spatial distribution using classical statistics and geostatistics parameters. The study was carried out in an experimental farm area, in Lavras, Minas Gerais State, Brazil, conventionally tilled in the last […]

Influence of ethyl-trinexapac on 15N accumulation and distribution and on highland rice yield

Rita de Cássia Félix Alvarez, Carlos Alexandre Costa Crusciol, Paulo Cesar Ocheuze Trivelin, João Domingos Rodrigues, Angela Cristina Camarim Alvarez

01/Dec/2007

The high rice grain yields ensured by sprinkler irrigation have encouraged the use of higher fertilizer doses, mainly the nitrogen fertilizers. However, an improper management of nitrogen fertilization may result in plant lodging. Application of plant regulators may redirect assimilates to grain production while limiting the vegetative growth. This study aimed to: evaluate the influence of the growth regulator Ethyl-trinexapac on plant growth parameters and on 15N accumulation and distribution in the whole plant and plant components, and determine the […]

Impact of organic residue management on soil quality indicators during replanting of eucalypt stands

Guilherme Montandon Chaer, Marcos Rogério Tótola

01/Dec/2007

Agricultural soil use induces changes in soil physical, chemical, and microbiological characteristics. These changes can eventually lead to a loss of soil quality and a consequent reduction in plant growth and productivity. The analysis of biochemical and microbiological soil quality indicators is relevant to monitor changes in soil quality and in the performance of key soil functions, such as the capacity of nutrient cycling and storage. This study reports on physical, chemical, and biochemical/microbiological quality indicators of soil under eucalyptus […]

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