3290 results

Aluminum hydroxy-interlayered minerals and chemical properties of a subtropical Brazilian Oxisol under no-tillage and conventional tillage

Alberto Vasconcellos Inda, José Torrent, Vidal Barrón, Cimélio Bayer

01/Feb/2010

No tillage systems significantly influence the soil system, but knowledge about the effects on the mineralogy of tropical and subtropical soils is limited. This study evaluated the long-term effects (26 years) of no-tillage (NT) on aluminum hydroxy-interlayered minerals of a subtropical Oxisol in Southern Brazil (Guarapuava, PR), compared to the same soil under conventional tillage (CT). The clay fraction (< 2 µm) in soil samples of the surface horizons of a field experiment under both management systems was analyzed by […]

Dendrometric parameters of eucalyptus and their relationship with physical-chemical characteristics of a Latosol in the Brazilian Cerrado

César Gustavo da Rocha Lima, Morel de Passos e Carvalho, Karen Cristina Pirola Narimatsu, Matheus Gustavo da Silva, Hernandez Andrade de Queiroz

01/Feb/2010

Soil mechanical penetration resistance exerts a strong influence on plant development since the root growth as well as crop yield are inversely related to this variable. On the other hand, soil organic matter and pH are also relevant for plant development, for being directly linked to soil nutrient availability. In the 2005/2006 growing season, the following dendrometric parameters of Eucalyptus camaldulensis were analyzed: (a) wood volume (WV), (b) perimeter at breast height (PBH) and c) plant height (PH), and the […]

Spatial variability of chemical attributes of an Oxisol under coffee cultivation

Samuel de Assis Silva, Julião Soares de Souza Lima, Alexandre Cândido Xavier, Mauri Martins Teixeira

01/Feb/2010

The objective of this study was to analyze the spatial variability of chemical attributes of an Oxisol. The experiment was conducted with Coffea arabica L., variety Catuai, at a depth of 0-0.2 m in a grid area totaling 50 points. The studied chemical attributes were: P, K, Ca, Mg, Na, S, Al, pH, H + Al, SB, t, T, V, m, MO, ISNa, equilibrium P and micronutrients (Zn, Fe, Mn, Cu, and B). The data were analyzed by descriptive statistical […]

Determination of normal nutrient ranges for cotton by the ChM, CND and DRIS methods

Ademar Pereira Serra, Marlene Estevão Marchetti, Antonio Carlos Tadeu Vitorino, José Oscar Novelino, Marcos Antônio Camacho

01/Feb/2010

The use of diagnosis methods for the determination of normal nutrient ranges is efficient since it is region-specific, thus not always applicable to other regions. This study aimed to determine the optimum nutrient ranges for cotton based on the Best likelihood (ChM), Diagnosis and Recommendation Integrated System (DRIS) and Compositional Nutrient Diagnosis (CND). The study was conducted in commercial cotton fields for the 2004/2005 growing season, in São Desidério, state of Bahia, Brazil. The total nutrient content of 65 whole […]

Phosphorus acquisition and yield of common bean: influence of forage grasses and phosphorus sources

Sílvio Júnio Ramos, Valdemar Faquin, Carlos Ribeiro Rodrigues, Carlos Alberto Silva, Fabrício William de Ávila, Regynaldo Arruda Sampaio

01/Feb/2010

In no-tillage or in crop-livestock integration systems, it is common the cultivation of common bean in succession to grasses. Due to the root systems morphology, differential secretion of various organic compounds by the roots, and crop residue decomposition, grasses may affect the soil P availability and the acquisition and utilization of P sources, apparently with low agronomic efficiency, for crops in succession. This study was carried out to evaluate the use of P in common bean yield in succession to […]

Soil tillage in grain and silage-producing areas and pasture: effect on tensile strength and aggregate friability

Marina Araújo Bavoso, Neyde Fabíola Balarezo Giarola, Cássio Antônio Tormena, Volnei Pauletti

01/Feb/2010

The understanding and quantification of soil use and management on the soil physical quality are important to develop and select sustainable agricultural systems. The purpose of this study was to evaluate the structural quality of a clayey Brazilian Oxisol under different production and soil tillage systems by measuring the tensile strength (TS) and to quantify aggregate friability (F). The study was conducted in Castro, Paraná state, in southern Brazil, using three production systems and seven soil tillage types, in a […]

Changes in soil organic matter along a chronosequence of an agrosilvipastoral system of eucalypt cultivation

Leonardus Vergutz, Roberto Ferreira Novais, Ivo Ribeiro da Silva, Nairam Félix de Barros, Tiago Novais Nunes, Antônio Augusto de Moraes Piau

01/Feb/2010

Agrosilvipastoral systems represent agro-forestry practices that allow greater diversity and sustainability of a cropping system. Soil organic matter (SOM) is one of the main indicators of the sustainability of a cropping system, especially in tropical soils. The objectives of this study were to investigate the impact of eucalypt cultivation on different C and N of SOM fractions on agrosilvipastoral systems over time. To this end, a chronosequence consisting of six implantation times of an agrosilvipastoral system was sampled. Time zero […]

Model calibration for flow rate and total phosphorous export simulations in the watersheds of the rivers conrado and Pinheiro, Pato Branco (PR)

Valmir Baltokoski, Maria Hermínia Ferreira Tavares, Ronalton Evandro Machado, Marcio Paulo de Oliveira

01/Feb/2010

Hydrological models developed to predict the impacts of non-point source pollution and land use and occupation on water quality have been extremely useful in the study of agricultural systems. For this purpose, the objective of this study was to evaluate the sensitivity of the model SWAT 2005 (Soil and Water Assessment Tool) to simulate the flow rate and total phosphorous flow mass. The research was conducted in two contiguous watersheds of the Conrado and Pinheiro rivers, affluents to the Pato […]

Relationship among soil attributes and ant activity in restinga soils

João Bosco Vasconcellos Gomes, Antonio Carlos Barreto, Miguel Michereff Filho, Wiviane Carlos Lima Vidal, Jefferson Luis da Silva Costa, Ary Teixeira de Oliveira-Filho, [...]

01/Feb/2010

In restinga soils with sand-quartzous constitution the influence of the organic fraction and biological activity on soil key functions is increased, e.g., the capacity of recycling and storing nutrients. The analysis of soil attributes and edaphic fauna at sites under different vegetation cover types is important to understand the behavior of these environments. In this study, chemical, physical and microbiological soil attributes of restinga sites and their relationships with ant populations under different vegetation types in the state of Sergipe […]

Genesis and classification of Oxisols in a highland toposequence of the upper Jequitinhonha Valley (MG)

Celmo Aparecido Ferreira, Alexandre Christófaro Silva, Pablo Vidal Torrado, Welington Willian Rocha

01/Feb/2010

The Brazilian System of Soil Classification (SiBCS) is a taxonomic system, open and in permanent construction, as new knowledge on Brazilian soils is obtained. The objective of this study was to characterize the chemical, physical, morphological, micro-morphological and mineralogical properties of four pedons of Oxisols in a highland toposequence in the upper Jequitinhonha Valley, emphasizing aspects of their genesis, classification and landscape development. The pedons occupy the following slope positions: summit – Red Oxisol (LV), mid slope (upper third) – […]

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