3312 results

Carbon balance and crop residue management in dynamic equilibrium under a no-till system in Campos Gerais

Ademir de Oliveira Ferreira, João Carlos de Moraes Sá, Mônica Gabrielle Harms, Simone Miara, Clever Briedis, Caio Quadros Netto, [...]

01/Nov/2012

The adoption of no-tillage systems (NT) and the maintenance of crop residues on the soil surface result in the long-term increase of carbon (C) in the system, promoting C sequestration and reducing C-CO2 emissions to the atmosphere. The purpose of this study was to evaluate the C sequestration rate and the minimum amount of crop residues required to maintain the dynamic C equilibrium (dC/dt = 0) of two soils (Typic Hapludox) with different textural classes. The experiment was arranged in […]

Impacts of different management systems on the physical quality of an Amazonian Oxisol

Elaine Maria Silva Guedes, Antonio Rodrigues Fernandes, Herdjania Veras de Lima, Ademar Pereira Serra, José Ribamar Costa, Rafael da Silva Guedes

01/Aug/2012

The physical quality of Amazonian soils is relatively unexplored, due to the unique characteristics of these soils. The index of soil physical quality is a widely accepted measure of the structural quality of soils and has been used to specify the structural quality of some tropical soils, as for example of the Cerrado ecoregion of Brazil. The research objective was to evaluate the physical quality index of an Amazonian dystrophic Oxisol under different management systems. Soils under five managements were […]

Relations between soil surface roughness, tortuosity, tillage treatments, rainfall intensity and soil and water losses from a red yellow latosol

Julieta Bramorski, Isabella C. De Maria, Renato Lemos e Silva, Silvio Crestana

01/Aug/2012

The soil surface roughness increases water retention and infiltration, reduces the runoff volume and speed and influences soil losses by water erosion. Similarly to other parameters, soil roughness is affected by the tillage system and rainfall volume. Based on these assumptions, the main purpose of this study was to evaluate the effect of tillage treatments on soil surface roughness (RR) and tortuosity (T) and to investigate the relationship with soil and water losses in a series of simulated rainfall events. […]

Digital soil mapping: strategy for data pre-processing

Alexandre ten Caten, Ricardo Simão Diniz Dalmolin, Luis Fernando Chimelo Ruiz

01/Aug/2012

The region of greatest variability on soil maps is along the edge of their polygons, causing disagreement among pedologists about the appropriate description of soil classes at these locations. The objective of this work was to propose a strategy for data pre-processing applied to digital soil mapping (DSM). Soil polygons on a training map were shrunk by 100 and 160 m. This strategy prevented the use of covariates located near the edge of the soil classes for the Decision Tree […]

Carbon fractions in toposequences of soils under eucalyptus with different use history

Elen Alvarenga Silva, Carlos Alberto Silva, Ivo Ribeiro Silva, João José G. S. M. Marques, Elias Frank de Araujo, Samara Andrade de Carvalho, [...]

01/Aug/2012

In Brazil, most forest stands have been planted on soils with some degree of physical, chemical or biological degradation. The protection of the trees for the soil, depending on the litter deposition, is a driving force of the restoration process of degraded areas. Since organic matter is related to many of the physical, chemical and biological soil properties, it is characterized as a key factor for the maintenance of the environmental quality of forest systems. The purpose of this study […]

Contribution of macroporosity to water flux of a soil under different tillage systems

Carlos Germán Soracco, Luis Alberto Lozano, Roberto Balbuena, Juan Manuel Ressia, Roberto Raúl Filgueira

01/Aug/2012

In view of the importance of the macroporosity for the water transport properties of soils, its quantitative assessment is a challenging task. Measurements of hydraulic conductivity (K) at different soil water tensions and the quantification of water-conducting macropores (θM) of a soil under different tillage systems could help understand the effects on the soil porous system and related hydraulic properties. The purpose of this study was to assess the effects of Conventional Tillage (CT), Chisel Plow (CP) and No Tillage […]

Risk of land salinization in baixo Acaraú, Ceará

Lydia Helena da Silva de Oliveira Mota, Andréa da Silva Gomes, Gustavo Souza Valladares, Regina Maria Fontenele Magalhães, Hugo Mota Ferreira Leite, Tibério Almeida da Silva

01/Aug/2012

Certain conditions of relief, climate and use can lead to the formation of saline and sodic soils, also called salt-affected soils. With a view to establish guidelines for management practices and land use in the region of Baixo Acaraú, Ceará, the purpose of this work was to generate a map of salinization risk. To classify levels of vulnerability, the pedology, geology, geomorphology and land use/cover were evaluated as well as slope altimetry information, treated in a GIS environment with an […]

Heavy metals in soils and plants in mango orchards in Petrolina, Pernambuco, Brazil

João Paulo Siqueira da Silva, Clístenes Williams Araújo do Nascimento, Caroline Miranda Biondi, Karina Patrícia Vieira da Cunha

01/Aug/2012

The monitoring of heavy metal concentrations in areas under intensive agriculture is essential for the agricultural sustainability and food safety. This paper evaluates the total contents of heavy metals in soils and mango trees in orchards of different ages (6, 7, 8, 9, 10, 11, 14, 16, 17, 19, and 26 years) in Petrolina, Pernambuco, Brazil. Soil samples were taken from the layers 0-20 cm and 20-40 cm, and mango leaves were collected in the growth stage. Areas of native […]

Magnetic susceptibility to identify landscape segments on a detailed scale in the region of Jaboticabal, São Paulo, Brazil

Mariana dos Reis Barrios, José Marques Junior, Alan Rodrigo Panosso, Diego Silva Siqueira, Newton La Scala Junior

01/Aug/2012

The agricultural potential is generally assessed and managed based on a one-dimensional vision of the soil profile, however, the increased appreciation of sustainable production has stimulated studies on faster and more accurate evaluation techniques and methods of the agricultural potential on detailed scales. The objective of this study was to investigate the possibility of using soil magnetic susceptibility for the identification of landscape segments on a detailed scale in the region of Jaboticabal, São Paulo State. The studied area has […]

Evaluation and quantification of the fractions silt, sand and clay by diffuse reflectance spectroscopy

Everson Cezar, Marcos Rafael Nanni, Marcelo Luiz Chicati, Ivan Granemann de Souza Junior, Antonio Carlos Saraiva da Costa

01/Aug/2012

Routine tests to determine physical and chemical soil properties have been used for several years. However, due to economic and environmental problems, new assessment methods must be developed. In this context, diffuse reflectance spectroscopy is a promising and quick tool in the determination of these properties. The objective of this work was to study the spectral behavior of the silt, sand and clay fractions and evaluate the possibility of quantifying these properties with regression models generated for each individual element. […]

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