Soil Physical Quality Indicators and Refinement of the Evaluation Method through the Srelative

This study aimed to verify the efficiency of indicators of measure of physical attributes’ alterations and to refine the Srelative determination method in order to increase its sensitivity to soil physical alterations. Soils under Ficus carica L. cultivation (with 0, 20, 40 and 60% of liquid bovine biofertilizer in the irrigation depth) and under forest were used. Parameters evaluated included soil granulometry, soil bulk and particle density, soil water retention curve (SWRC), porosity and the indices S and Srelative. The experimental design was completely randomized with four replicates. For Srelative refinement, with the SWRC containing only textural porosity, the soil was dispersed in water and with the addition of 1 N sodium hydroxide (with and without removal of sodium through washing). An ANOVA was performed for 0, 20, 40 and 60% of biofertilizer in 0-10, 10-20 and 20-30 layers; Dunnett test was used to compare the mean values of S-index and Srelative-index. With respect to four methods to obtain the Srelative-index the means were compared by Tukey test. Tests of line parallelism and intercept were performed for the regressions between each of the soil physical variables and Srelative-index obtained. It was found that S and Srelative indices were sensitive to soil physical alterations caused by the application of the biofertilizer; Srelative-index was sensitive to variation in soil bulk density and total porosity and the Srelative-index obtained from the method of soil dispersion in water is more sensitive to soil physical alterations in comparison to Srelative-index obtained through ADFE.

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Pedotransfer functions of soil water properties to estimate the S-index

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v22n7p465-470 ◽

2018 ◽

Vol 22 (7) ◽

pp. 465-470

Author(s):

João H. Caviglione

Keyword(s):

Soil Water ◽

Water Retention ◽

Field Conditions ◽

Pedotransfer Functions ◽

Water Retention Curve ◽

Coefficient Of Determination ◽

Native Forest ◽

Soil Water Retention Curve ◽

Soil Water Retention ◽

Soil Physical Quality

ABSTRACT One big challenge for soil science is to translate existing data into data that is needed. Pedotransfer functions have been proposed for this purpose and they can be point or parametric when estimating the water retention characteristics. Many indicators of soil physical quality have been proposed, including the S-Index proposed by Dexter. The objective of this study was to assess the use of pedotransfer functions for soil water retention to estimate the S-index under field conditions in the diversity of soils of the Paraná state. Soil samples were collected from 36 sites with textures ranging from sandy to heavy clay in the layers of 0-0.10 and 0.10-0.20 m and under two conditions (native forest and cultivated soil). Water content at six matric potentials, bulk density and contents of clay, sand and silt were determined. Soil-water retention curve was fitted by the van Genuchten-Mualem model and the S-index was calculated. S-index was estimated from water retention curves obtained by the pedotransfer function of Tomasella (point and parametric). Although the coefficient of determination varied from 0.759 to 0.895, modeling efficiency was negative and the regression coefficient between observed and predicted data was different from 1 in all comparisons. Under field conditions in the soil diversity of the Paraná state, restrictions were found in S-index estimation using the evaluated pedotransfer functions.

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Gamma-ray beam attenuation as an auxiliary technique for the evaluation of the soil water retention curve

Scientia Agricola ◽

10.1590/s0103-90161998000300019 ◽

1998 ◽

Vol 55 (3) ◽

pp. 498-502 ◽

Cited By ~ 8

Author(s):

O.O.S. BACCHI ◽

K. REICHARDT ◽

J.C.M. OLIVEIRA ◽

D.R. NIELSEN

Keyword(s):

Soil Moisture ◽

Bulk Density ◽

Water Retention ◽

Gamma Ray ◽

Soil Bulk Density ◽

Water Retention Curve ◽

Soil Water Retention Curve ◽

Soil Water Retention ◽

Retention Curve ◽

Beam Attenuation

The soil water retention curve is fundamental for the hydraulic characterization of a soil and has many applications in agricultural research as well as in practical agriculture. A new procedure for soil moisture and soil bulk density evaluation inside closed pressure chambers through gamma-ray beam attenuation is presented. The proposed procedure presents several advantages in relation to the traditional process: avoids the need of continuous sample manipulation; minimizes the problem of hysteresis; allows a more precise evaluation of soil moisture by taking into account changes of soil bulk density due to swelling or shrinking on addition or removal of water; allows frequent evaluation of soil moisture without the need of opening the pressure chamber; allows a more precise judgement of equilibrium; reduces drastically the time of the determination of the retention curve and allows easy automation of data acquisition by a computer.

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SOIL WATER RETENTION CURVE AND S INDEX AS SOIL PHYSICAL QUALITY INDICATORS FOR INTEGRATED PRODUCTION SYSTEMS

Engenharia Agrícola ◽

10.1590/1809-4430-eng.agric.v38n1p64-73/2018 ◽

2018 ◽

Vol 38 (1) ◽

pp. 64-73 ◽

Cited By ~ 1

Author(s):

Wellington de A. Magalhães ◽

Onã da S. Freddi ◽

Flávio J. Wruck ◽

Fabiano A. Petter ◽

Renan F. R. Tavanti

Keyword(s):

Soil Water ◽

Water Retention ◽

Production Systems ◽

Water Retention Curve ◽

Soil Water Retention Curve ◽

Soil Water Retention ◽

Retention Curve ◽

Physical Quality ◽

Integrated Production ◽

Soil Physical Quality

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Influence of physical attributes and pedotransfer function for predicting water retention in management systems

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n11p746-751 ◽

2017 ◽

Vol 21 (11) ◽

pp. 746-751 ◽

Cited By ~ 1

Author(s):

André C. Auler ◽

Luiz F. Pires ◽

Maria C. Pineda

Keyword(s):

Soil Water ◽

Water Retention ◽

Total Porosity ◽

Pedotransfer Functions ◽

Management Systems ◽

Water Retention Curve ◽

Soil Water Retention Curve ◽

Soil Water Retention ◽

Physical Attributes ◽

Ct System

ABSTRACT The aims of this study were to evaluate the effects of the soil structural physical attributes on the water retention and to develop pedotransfer functions (PTFs) for the estimation of the soil water content (θ) at different matric potentials of a Dystrophic Red Latosol (Hapludox) under conventional tillage (CT) and no-tillage (NT) soil management systems. The effects of long-term CT and NT (over 25 years) management on the soil bulk density (BD), total porosity (TP), macroporosity (Ma), microporosity (Mi) and water retention were investigated. The PTFs were developed to predict θ and used to evaluate the soil water retention curve only for the NT system. The NT system was characterized by smaller values of the soil BD and higher values of the soil TP and Mi than the CT system. The NT system exhibited a higher θ retained than the CT system for the pore-size interval of 0.2–30 μm. However, the CT system exhibited a large amount of water retention for pores smaller than 0.2 μm. The PTFs were utilized to estimate θ at matric potentials of -1, -3, -6, -10, -33, -100, -400, -800, and -1,500 kPa with adequate accuracy. The soil BD, Ma, Mi and sand content were the main variables considered to estimate θ for the different matric potentials evaluated.

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