94 results

Spatial patterns of preconsolidation pressure and soil moisture along transects in two directions under coffee

Ivoney Gontijo, Moacir de Souza Dias Junior, Paulo Tácito Gontijo Guimarães, Marcelo Silva de Oliveira, Ayodele Ebenezer Ajayi

01/Aug/2011

Information on the spatial structure of soil physical and structural properties is needed to evaluate the soil quality. The purpose of this study was to investigate the spatial behavior of preconsolidation pressure and soil moisture in six transects, three selected along and three across coffee rows, at three different sites under different tillage management systems. The study was carried out on a farm, in Patrocinio, state of Minas Gerais, in the Southeast of Brazil (18 º 59 ‘ 15 ” […]

Structural changes in latosols of the cerrado region: I – relationships between soil physical properties and least limiting water range

Eduardo da Costa Severiano, Geraldo César de Oliveira, Moacir de Souza Dias Júnior, Katia Aparecida de Pinho Costa, Fabiano Guimarães Silva, Silvio Marcos Ferreira Filho

01/Jun/2011

The agricultural potential of Latosols of the Brazilian Cerrado region is high, but when intensively cultivated under inappropriate management systems, the porosity can be seriously reduced, leading to rapid soil degradation. Consequently, accelerated erosion and sedimentation of springs and creeks have been observed. Therefore, the objective of this study was to evaluate structural changes of Latosols in Rio Verde, Goiás, based on the Least Limiting Water Range (LLWR), and relationships between LLWR and other physical properties. Soil samples were collected […]

Least limiting water range in soil under crop rotations and chiseling

Juliano Carlos Calonego, Ciro Antonio Rosolem

01/Jun/2011

Soil water availability to plants is affected by soil compaction and other variables. The Least Limiting Water Range (LLWR) comprises soil physical variables affecting root growth and soil water availability, and can be managed by either mechanical or biological methods. There is evidence that effects of crop rotations could last longer than chiseling, so the objective of this study was to assess the effect of soil chiseling or growing cover crops under no-till (NT) on the LLWR. Crop rotations involving […]

Improvement of a testing apparatus for dynamometry: procedures for penetrometry and influence of strain rate to quantify the tensile strength of soil aggregates

Getulio Coutinho Figueiredo, Alvaro Pires da Silva, Cássio Antonio Tormena, Neyde Fabíola Balarezo Giarola, Sergio Oliveira Moraes, Brivaldo Gomes de Almeida

01/Apr/2011

Soil penetration resistance (PR) and the tensile strength of aggregates (TS) are commonly used to characterize the physical and structural conditions of agricultural soils. This study aimed to assess the functionality of a dynamometry apparatus by linear speed and position control automation of its mobile base to measure PR and TS. The proposed equipment was used for PR measurement in undisturbed samples of a clayey “Nitossolo Vermelho eutroférrico” (Kandiudalfic Eutrudox) under rubber trees sampled in two positions (within and between […]

Compressibility, penetration resistance and least limiting water range of a Yellow Ultisol under sugarcane in the Coastal Tablelands of Alagoas State

Edson Patto Pacheco, José Ramon Barros Cantalice

01/Apr/2011

The intensive traffic of agricultural machinery of cultivation and harvesting operations of sugarcane can promote soil compaction and affect crop yield and longevity. One of the ways to evaluate soil degradation due to compaction is by analyses of soil compressibility and least limiting water range. The objective of this study was to evaluate the effect of sugarcane cultivation on pre-compaction pressure (sp), laboratory-determined soil penetration resistance (LPS) and on the least limiting water range (LLWR) of a cohesive Yellow Ultisol […]

Load bearing capacity and critical water content of a Latossol induced by different managements

Cezar Francisco Araujo-Junior, Moacir de Souza Dias Junior, Paulo Tácito Gontijo Guimarães, Elifas Nunes Alcântara

01/Feb/2011

Different weed managements in coffee have led to structural changes, affecting the soil physical quality. Therefore, information on the load bearing capacity of the soil under different weed managements is essential to establish a sustainable soil management under coffee. The objectives of this study were to: (a) assess the influence of different weed managements over three decades on the load bearing capacity of a Dystroferric Red Latosol (LVdf) cultivated with coffee on the Epamig Farm in São Sebastião do Paraíso, […]

Pedotransfer functions to estimate proctor test parameters under different tillage systems

Carina Rosa Álvarez, Federico Guillermo Micucci, Carolina Bustingorri, Miguel Angel Taboada

01/Dec/2010

The Proctor test is time-consuming and requires sampling of several kilograms of soil. Proctor test parameters were predicted in Mollisols, Entisols and Vertisols of the Pampean region of Argentina under different management systems. They were estimated from a minimum number of readily available soil properties (soil texture, total organic C) and management (training data set; n = 73). The results were used to generate a soil compaction susceptibility model, which was subsequently validated using a second group of independent data (test data […]

Physical properties of a typic paleudalf under long-term no-tillage and cropping systems

Mastrângello Enívar Lanzanova, Flávio Luiz Foletto Eltz, Rodrigo da Silveira Nicoloso, Telmo Jorge Carneiro Amado, Dalvan José Reinert, Marta Rodrigues da Rocha

01/Aug/2010

No-tillage associated to cover crops may maintain soil quality, improving or preserving favorable soil physical conditions for plant growth. This study assessed soil bulk density, porosity, penetration resistance, and water infiltration of a PALEUDALF, in the Experimental Area of the Soil Science Department of the Federal University of Santa Maria, in Santa Maria, RS, Brazil, in an experiment started in 1991, with the following crop successions and rotations: (1) Corn/Soybean – Jackbean – MFP; (2) Bare soil – SDES; (3) […]

Water infiltration in soil as influenced by chiseling and crop rotations

Maryara Buriola Prando, Dácio Olibone, Ana Paula Encide Olibone, Ciro Antonio Rosolem

01/Jun/2010

In soils with physical and/or physical hydric restrictions for root growth, it may be a viable strategy to increase crop productivity by increasing water storage potential through improvements in water infiltration. Accordingly, the objective of this study was to determine water infiltration in a Hapludult in three crop rotations under no-tillage, with and without initial chiseling. Crop rotations consisted of: millet/soybean/sorghum/maize/sorghum; millet/soybean/Brachiaria ruziziensis/corn/Brachiaria ruziziensis; and millet/soybean/Brachiaria ruziziensis + castor bean/corn/Brachiaria ruziziensis + castor bean. Water infiltration in soil was evaluated […]

Soil shear strength under non-irrigated and irrigated short duration grazing systems

Rita de Cássia Ribeiro Carvalho, Wellington Willian Rocha, José Cardoso Pinto, Bruno da Silva Pires, Moacir de Souza Dias Junior, Ayeska Hubner Braga Nunes

01/Jun/2010

Pasture productivity can drop due to soil compaction caused by animal trampling. Physical and mechanical alterations are therefore extremely important indicators for pasture management. The objective of this research was to: draw and evaluate the Mohr failure line of a Red Yellow Latossol under different pasture cycles and natural forest; calculate apparent cohesion; observe possible physical alterations in this soil; and propose a correction factor for stocking rates based on shear strength properties. This study was conducted between March/2006 and […]

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