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All publications of “Paulo Ivonir Gubiani”

11 results

Tipping Bucket Prototype for Automatic Quantification of Surface Runoff Rate in Plots

André Somavilla, Paulo Ivonir Gubiani ORCID logo , Anderson Luiz Zwirtz

07/Jan/2019

ABSTRACT: Quantification of runoff rate is an onerous task with non-automated devices; it requires a lot of manual labor to perform measurements. In this study, an automatic device to quantify the surface runoff rate from plots with a small area was developed and tested. The prototype was based on the tipping bucket technique and built with reused materials. Its performance was tested in the laboratory and a calibration curve was developed to improve measurement accuracy. The device can be used […]

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Transpiration Reduction Factor and Soybean Yield in Low Land Soil with Ridge and Chiseling

Paulo Ivonir Gubiani, Eduardo Augusto Müller, André Somavilla, Anderson Luiz Zwirtes, Rodrigo Pivoto Mulazzani, Enio Marchesan

10/May/2018

ABSTRACT Water and oxygen deficiencies in the soybean crop cultivated on lowland soils are an important topic of research. The objective of this study was to investigate changes in water and oxygen supply and soybean yield caused by soil management in lowland soils. A soybean crop was grown under four soil conditions: no-tillage (NT), chiseling (CH), ridge tillage on no-tillage (NTR), and ridge tillage on chiseling (CHR). Soil bulk density, total porosity, macro- and microporosity, air permeability, and saturated hydraulic […]

Rheological Parameters as Affected by Water Tension in Subtropical Soils

Patricia Pértile, José Miguel Reichert, Paulo Ivonir Gubiani, Dörthe Holthusen, André da Costa

06/Jun/2016

ABSTRACT Rheological parameters have been used to study the interaction between particles and the structural strength of soils subjected to mechanical stresses, in which soil composition and water content most strongly affect soil resistance to deformation. Our objective was to evaluate the effect of water tension on rheological parameters of soils with different mineralogical, physical, and chemical composition. Surface and subsurface horizons of four Oxisols, two Ultisols, one Alfisol, and one Vertisol were physically and chemically characterized; their rheological parameters […]

BEYOND THE “LEAST LIMITING WATER RANGE”: RETHINKING SOIL PHYSICS RESEARCH IN BRAZIL

Quirijn de Jong van Lier, Paulo Ivonir Gubiani

01/Jul/2015

As opposed to objective definitions in soil physics, the subjective term “soil physical quality” is increasingly found in publications in the soil physics area. A supposed indicator of soil physical quality that has been the focus of attention, especially in the Brazilian literature, is the Least Limiting Water Range (RLL), translated in Portuguese as “Intervalo Hídrico Ótimo” or IHO. In this paper the four limiting water contents that define RLL are discussed in the light of objectively determinable soil physical […]

RELATIONSHIP BETWEEN BULK DENSITY AND WATER CONTENT OF AN OXISOL SUBJECTED TO REPEATED CYCLES OF EXPANSION AND CONTRACTION

Paulo Ivonir Gubiani, Quirijn de Jong Van Lier, Marta Sandra Drescher, Henrique Caletti Mezzomo, Camila Machado Costa Veiga

01/Jan/2015

Soil compaction is an undesirable consequence of land use for crop production, especially under cultivation with minimum soil turnover as in the no-tillage system (NTS). However, the compaction caused by machine traffic on soils under NTS does not make crop production unviable, indicating that some intrinsic mechanisms promote the reversion of soil compaction. In this study, the influence of alternate contraction and expansion cycles was evaluated with regard to the bulk density (ρ) of a Latossolo Vermelho argiloso (clayey Oxisol) […]

Interaction between water availability and soil compaction on common bean growth and yield

Paulo Ivonir Gubiani, José Miguel Reichert, Dalvan José Reinert

01/Jun/2014

Soil physical properties, plant growth, and water availability in the soil are factors that interact in response to changes in soil structure. Knowing how these factors interact in field conditions is of great importance for management of soil compaction for crop yield. In this paper, three levels of soil compaction, with and without irrigation, were assessed in regard to growth and yield of common bean (Phaseolus vulgaris L.). The probability of interaction between soil compaction and irrigation was 88 % […]

Corn growth and yield associated with the least limiting water range

Paulo Ivonir Gubiani, Rafael Ziani Goulart, José Miguel Reichert, Dalvan José Reinert

01/Dec/2013

The least limiting water range (LLWR) has been widely used as an agronomic indicator of soil physical quality, however only a few studies have linked the LLWR to the plants growth and yield. The scarce results are insufficient to confirm or rebut the efficiency of LLWR, but indicate a discrepancy between LLWR and crop yields. The purpose of this study was to analyze the correlation of LLWR with variables of growth and grain yield of corn (Zea mays L.) in […]

Hydric and mechanical indicators of soil compaction and plant growth

Paulo Ivonir Gubiani, José Miguel Reichert, Dalvan José Reinert

01/Feb/2013

The effect of soil compaction on plant growth is widely used as orientation for soil management. Although the limiting water range (LLWR) underlies the systematization of the relationship between compaction and physical factors directly related to plant growth, its efficiency to predict biological responses, especially of grain yield, has not yet been proven. Results of research at the cellular level indicate that the water and mechanical stress levels that occur in the roots during soil drying are partially represented by […]

Structural and mechanical changes in a lowland soil under flooded rice

Marcelo Ivan Mentges, José Miguel Reichert, Paulo Ivonir Gubiani, Dalvan José Reinert, Alencar Xavier

01/Feb/2013

The conversion of natural areas for agricultural use can degrade the soil structure and increase the occurrence of compression. This study aimed to evaluate changes in the physico-mechanical and hydro-physical properties of an Endoaqualf, caused by the conversion of a natural area into a rice field. Hydro-physical (density, porosity, macroporosity, microporosity, void ratio, and water retention) and mechanical properties (preconsolidation pressure, compression index, coefficient of decompression, and recovery rate) were evaluated in the horizons A1 (0.0-0.25 m), A2 (0.25-0.51 m), […]

Implications of the variability in soil penetration resistance for statistical analysis

Paulo Ivonir Gubiani, José Miguel Reichert, Dalvan José Reinert, Neiva Somavilla Gelain

01/Oct/2011

Soil penetration resistance (PR) is a measure of soil compaction closely related to soil structure and plant growth. However, the variability in PR hampers the statistical analyses. This study aimed to evaluate the variability of soil PR on the efficiency of parametric and nonparametric analyses in indentifying significant effects of soil compaction and to classify the coefficient of variation of PR into low, medium, high and very high. On six dates, the PR of a typical dystrophic Red Ultisol under […]

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