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8 results

Estimation of the Retention and Availability of Water in Soils of the State of Santa Catarina

Diego Bortolini, Jackson Adriano Albuquerque

02/Nov/2018

ABSTRACT: Soil water retention and availability are important properties for agricultural production, which can be measured directly or estimated by pedotransfer functions. Some studies on this topic were carried out in Santa Catarina, Brazil. To improve the estimates, it is necessary to evaluate other properties, to analyze more soil types, as well as to use other analysis techniques such as artificial neural networks and regression trees. Thus, the objective of the study was to estimate the field capacity (FC), permanent […]

Bulk Density Prediction for Histosols and Soil Horizons with High Organic Matter Content

Sidinei Julio Beutler, Marcos Gervasio Pereira, Wagner de Souza Tassinari, Michele Duarte de Menezes, Gustavo Souza Valladares, Lúcia Helena Cunha dos Anjos

09/Mar/2017

ABSTRACT Bulk density (Bd) can easily be predicted from other data using pedotransfer functions (PTF). The present study developed two PTFs (PTF1 and PTF2) for Bd prediction in Brazilian organic soils and horizons and compared their performance with nine previously published equations. Samples of 280 organic soil horizons used to develop PTFs and containing at least 80 g kg-1 total carbon content (TOC) were obtained from different regions of Brazil. The multiple linear stepwise regression technique was applied to validate […]

Correction of resistance to penetration by pedofunctions and a reference soil water content

Moacir Tuzzin de Moraes, Henrique Debiasi, Julio Cezar Franchini, Vanderlei Rodrigues da Silva

01/Dec/2012

The soil penetration resistance is an important indicator of soil compaction and is strongly influenced by soil water content. The objective of this study was to develop mathematical models to normalize soil penetration resistance (SPR), using a reference value of gravimetric soil water content (U). For this purpose, SPR was determined with an impact penetrometer, in an experiment on a Dystroferric Red Latossol (Rhodic Eutrudox), at six levels of soil compaction, induced by mechanical chiseling and additional compaction by the […]

The efficiency of different estimation methods of hydro-physical limits

Emma María Martínez, Tomas Serafín Cuesta, Javier José Cancela

01/Dec/2012

The soil water available to crops is defined by specific values of water potential limits. Underlying the estimation of hydro-physical limits, identified as permanent wilting point (PWP) and field capacity (FC), is the selection of a suitable method based on a multi-criteria analysis that is not always clear and defined. In this kind of analysis, the time required for measurements must be taken into consideration as well as other external measurement factors, e.g., the reliability and suitability of the study […]

Estimation of water retention and availability in soils of Rio Grande do Sul

José Miguel Reichert, Jackson Adriano Albuquerque, Douglas Rodrigo Kaiser, Dalvan José Reinert, Felipe Lavarda Urach, Reimar Carlesso

01/Dec/2009

Dispersed information on water retention and availability in soils may be compiled in databases to generate pedotransfer functions. The objectives of this study were: to generate pedotransfer functions to estimate soil water retention based on easily measurable soil properties; to evaluate the efficiency of existing pedotransfer functions for different geographical regions for the estimation of water retention in soils of Rio Grande do Sul (RS); and to estimate plant-available water capacity based on soil particle-size distribution. Two databases were set […]

Estimating soil susceptibility to compaction and load support capacity based on physical parameters of soils from Rio Grande do Sul State

Luis Eduardo Akiyoshi Sanches Suzuki, Dalvan José Reinert, José Miguel Reichert, Cláudia Liane Rodrigues de Lima

01/Jun/2008

Quantifying the relationship between physical and mechanical soil properties can contribute to the development of pedotransfer functions that allow estimating hard-to-measure soil properties. The objective of this study was to evaluate the interrelations between susceptibility to compaction and load support with some physical properties of soils from Southern Brazil. Penetration resistance, moisture, bulk density and compressibility of six soils were evaluated. In a model including soil moisture and bulk density as independent variables, the relation with penetration resistance values obtained […]

Pedotransfer functions for the soil water retention and soil resistance to penetration curves

Álvaro Pires da Silva, Cássio Antonio Tormena, Jonez Fidalski, Silvia Imhoff

01/Feb/2008

Pedotransfer functions (PTFs) are useful tools to obtain estimates of soil physical properties such as the soil water retention curve (SWRC) and the soil resistance to penetration curve (SRPC), which are important inherent soil properties and difficult to measure. Most of the studies in the literature report PTFs only in relation to SWRC estimates. An important and necessary advance in this research area would be the development of PTFs for a simultaneous estimation of the SWRC and SRPC, which is […]

Incorporation of the bulk density to two models adjusted to the soil water retention curve

C. A. Tormena, A. P. Silva

01/Jun/2002

The soil water retention curve plays a fundamental role in the development of studies on the dynamics of soil water, modeling of physical soil processes and plant growth. The retention curve is usually obtained by simultaneously measuring water content (θ) and soil water potential (ψ) in a single sample. An alternative procedure is to use several samples per ψ to describe the retention curve. The use of this procedure requires that the variation factors which exist among the samples are […]