MOISTURE-RETENTION PARAMETERS FOR COARSE-TEXTURED SOILS IN SOUTHERN ALBERTA

1989 ◽  
Vol 69 (2) ◽  
pp. 263-272 ◽  
Author(s):  
D. R. BENNETT ◽  
T. ENTZ
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Field Capacity ◽  
Soil Series ◽  
Moisture Retention ◽  
Retention Capacity ◽  
Southern Alberta ◽  
Laboratory Procedures ◽  
Retention Parameters

A combination of field and laboratory procedures was used to estimate moisture-retention parameters of four coarse-textured soil series in southern Alberta. In situ field capacity moisture content was substantially higher than estimates based on conventional laboratory methods, resulting in significant underestimation of total available moisture. Moisture-retention capacity of all four soil series was found to be adequate for irrigation development. Empirical equations were developed to estimate the upper and lower limits of moisture retention on the basis of particle-size distribution, as determined by the Bouyoucos hydrometer method. Five alternative empirical methods were also evaluated for use in predicting moisture-retention parameters of coarse-textured soils. Equations presented by Rawls et al. (1982) were found to have the best relationship with southern Alberta data for both field capacity and wilting point. Key words: Coarse-textured soils, moisture-retention parameters, particle-size distribution, empirical models, irrigation suitability

scholarly journals Phosphorus retention by granulated apatite: assessing maximum retention capacity, kinetics and retention processes

2021 ◽  
Vol 83 (4) ◽  
pp. 792-802
Author(s):  
Laura Delgado-González ◽  
Bruno Lartiges ◽  
Mathieu Gautier ◽  
Stéphane Troesch ◽  
Pascal Molle
Keyword(s):  
Particle Size ◽  
Calcium Phosphate ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Calcium Phosphates ◽  
Rate Coefficients ◽  
Phosphorus Retention ◽  
Retention Capacity ◽  
Phosphate Retention ◽  
Granule Surface

Abstract Natural apatites have previously shown a great capacity for phosphate retention from wastewater. However, its fine particle size distribution may lead to a premature clogging of the filter. Accordingly, a granulated apatite product was developed and manufactured in order to control the particle size distribution of the media. Experiments were conducted on laboratory columns to assess their phosphorus retention capacity, to identify the processes involved in phosphorus retention and to evaluate their kinetic rates. The results showed phosphorus retention capacities of 10.5 and 12.4 g PO4-P·kg−1 and kinetic rate coefficients in the range of 0.63 and 0.23 h−1 involving lower values than those found for natural apatites in previous studies. Scanning Electron Microscopy images showed that apatite particles in the granules were embedded in the binder and were not readily accessible to act as seeds for calcium phosphate precipitation. The retention processes differ depending on the supersaturation of the solution with respect to calcium phosphate phases: at low calcium concentrations (69.8 ± 3.9 mg·L−1), hydroxyapatite precipitates fill up the porosity of the binder up to a depth of 100–300 μm from the granule surface; at higher calcium concentrations (112.7 ± 7.4 mg·L−1) precipitation occurs at the granule surface, forming successive layers of hydroxyapatite and carbonated calcium phosphates.

scholarly journals Moisture retention and plasticity of highly calcareous soils in Egypt.

1976 ◽  
Vol 24 (1) ◽  
pp. 43-57
Author(s):  
W.P. Stakman ◽  
B.G. Bishay
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Sandy Loam ◽  
Calcareous Soils ◽  
Liquid Limit ◽  
Plasticity Index ◽  
Plastic Limit ◽  
Moisture Retention ◽  
Unsaturated Condition

Particle size distribution, moisture retention curves and consistency limits were determined for six soils from northwestern Egypt. The soils contained 25-61% CaCO3 and attapulgite was the major clay mineral. In the clay and clay loam soils the CaCO3 was predominantly in the silt and clay fractions, in the sandy loam it was regularly distributed over the clay, silt and sand fractions and in the loamy sand it was mainly in the sand fraction. Decalcification shifted the particle size distribution to a coarser texture class and increased porosity and moisture content. Liquid limit and plasticity index increased with increasing clay and CaCO3 contents up to 40% clay and 35% CaCO3. The plastic limit stayed rather constant at increasing clay and CaCO3 contents. The liquid limit corresponded with suctions of pF 1.3-1.9 within the flex range from the saturated to the unsaturated condition of the pF curves. The plastic limit and the plasticity index corresponded with pF 2.1-3.0 and 2.6-3.8, respectively. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Using Different Approaches of Particle Size Analysis for Estimation of Water Retention Capacity of Soils: Example of Keszthely Mountains (Hungary)

2021 ◽  
Vol 17 (1) ◽  
pp. 37-50
Author(s):  
Orsolya Szecsődi ◽  
András Makó ◽  
Viktória Labancz ◽  
Gyöngyi Barna ◽  
Borbála Gálos ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Soil Properties ◽  
Size Distribution ◽  
Water Retention ◽  
Laser Diffraction ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Sedimentation Method ◽  
Pre Treatment

PSD (particle size distribution) is a key factor affecting soil hydro-physical properties (e.g. hydraulic conductivity and water retention), which makes its determination essential. Climate change increases the importance of water retention and permeability as extreme weather events can severely impair the water supply of drought-sensitive vegetation. The amount of water in soils is expected to decrease. The modified Thornthwaite model considers soil properties such as root depth, topsoil layer thickness and particle size distribution (silt and clay fraction) of soil particles combined with the most significant soil properties. At the beginning of the research, we developed a laser diffraction method to replace the standard based “pipette” sedimentation method. The theoretical background of laser diffraction measurements is already known, but their practical application for estimating soil water retention capacity is still poorly understood. The pre-sieving of soil aggregates, the pre-treatment (disaggregation and dispersion) of the samples greatly influence the obtained results. In addition to the sedimentation method, laser diffraction measurements (Malvern Mastersizer 3000) were applied with three variants of pre-treatment. For comparison, the results of a Leptosol, a Cambisol, and a Luvisol were prepared for the first modified Thornthwaite water balance model. Significant differences appeared, especially during drought periods, which could be a basis for studying soil drought sensitivity. The development of our method can estimate the water retention capacity of soil, which could support adaptive forest management plans against climatic and pedological transformations.

Effects of Particle Size Distribution on Corrosion Rate of Carbon Steel in Soil

2020 ◽  
Vol 69 (4) ◽  
pp. 102-106
Author(s):  
Shota Ohki ◽  
Shingo Mineta ◽  
Mamoru Mizunuma ◽  
Soichi Oka ◽  
Masayuki Tsuda
Keyword(s):  
Particle Size ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Particle Size Distribution ◽  
Size Distribution
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