scholarly journals Physical Properties of Various Coconut Coir Dusts Compared to Peat

HortScience ◽  
2005 ◽  
Vol 40 (7) ◽  
pp. 2138-2144 ◽  
Author(s):  
Manuel Abad ◽  
Fernando Fornes ◽  
Carolina Carrión ◽  
Vicente Noguera ◽  
Patricia Noguera ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Physical Properties ◽  
Size Distribution ◽  
Water Holding Capacity ◽  
Total Water ◽  
Air Content ◽  
Coir Dust ◽  
Coarseness Index ◽  
Water Holding

Selected physical properties of 13 coconut coir dusts from Asia, America, and Africa were compared to physical properties of sphagnum peat. All properties studied differed significantly between and within sources, and from the peat. Coir dusts from India, Sri Lanka, and Thailand were composed mainly of pithy tissue, whereas most of those from Costa Rica, Ivory Coast, and Mexico contained abundant fiber which was reflected by a higher coarseness index (percentage by weight of particles larger than 1 mm in diameter). Coir dust was evaluated as a lightweight material, and its total porosity was above 94% (by volume). It also exhibited a high air content (from 24% to 89% by volume) but a low easily available and total water-holding capacity which ranged from <1% to 36% by volume and from 137 to 786 mL·L–1, respectively. Physical properties of coir dust were strongly dependent on particle size distribution. Both easily available and total water-holding capacity declined proportionally with increasing coarseness index, while air content was positively correlated. Relative hydraulic conductivity in the range of 0 to 10 kPa suction dropped as particle size increased. Coir dusts with a particle size distribution similar to peat showed comparatively higher aeration and lower capacity to hold total and easily available water. An air–water balance similar to that in peat became apparent in coir dust at a comparatively lower coarseness index (29% vs. 63% by weight in peat). Stepwise multiple regression analysis showed that particles with diameters in the range of 0.125 to 1 mm had a remarkable and highly significant impact on the physical properties studied, while particles <0.125 mm and >1 mm had only a slight or nonsignificant effect.

Impact of Biochar on Water Holding Capacity of Two Chinese Agricultural Soil

2014 ◽  
Vol 941-944 ◽  
pp. 952-955 ◽  
Author(s):  
Dao Yuan Wang ◽  
Deng Hua Yan ◽  
Xin Shan Song ◽  
Hao Wang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Soil Type ◽  
Agricultural Soil ◽  
Water Retention ◽  
Water Holding Capacity ◽  
Walnut Shell ◽  
Retention Characteristics ◽  
Water Holding

Adding biochar to agricultural soil has been suggested as an approach to enhance soil carbon sequestration. Biochar has also been used as a soil amendment to reduce nutrient leaching, reduce soil acidity and improve water holding capacity. Walnut shells and woody material are waste products of orchards that are cheap, carbon-rich and good feedstock for production of biochar. The effectiveness of biochar as an amendment varies considerably as a function of its feedstock, temperature during pyrolysis, the biochar dose to soil, and mechanical composition. Biochar was produced from pyrolysis of walnut shell at 900 °C and soft wood at 600 to 700 °C. We measured the effect of these different parameters in two types of agricultural soil in Jilin and Beijing, China, a silt clay loam and a sandy loam, on the soils’ particle size distribution and water retention characteristics. Biochars with two different doses were applied to each soil type. Soil field capacity and permanent wilting point were measured using a pressure plate extractor for each combination of biochar and soil type. The results show that the effect of biochar amendment on soil water retention characteristics depend primarily on soil particle size distribution and surface characteristics of biochar. High surface area biochar can help raise the water holding capacity of sandy soil.

The influence of particle size distribution on soil physical properties

1986 ◽  
Vol 106 (3) ◽  
pp. 527-535 ◽  
Author(s):  
G. D. Towner
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Physical Properties ◽  
Size Distribution ◽  
Soil Physical Properties ◽  
The Other ◽  
Saturated Soils ◽  
Fine Silt ◽  
Significant Difference ◽  
Field Behaviour

SummaryBatcombe series soils readily break down to good tilths, Beccles series soils form cloddy seed beds that are resistant to weathering, and Stackyard series soils form unstable tilths that readily break down. The soils differ in their particle-size distribution. The proposition that such differences contributed to the differences in field behaviour was examined by forming artificial soils, each of which was made up from particles of one of the soils, but redistributed with respect to size in the proportion in which they occurred in one of the other soils.As a measure of the relevant physical properties, breaking strengths and bulk densities of cylindrical ‘clods’ moulded from the artificial soils were determined. To aid interpretation of the observed soil properties, similar measurements were made on individual fractions, on various other mixtures and on the parent soils.The breaking strengths of the soils made up to a given particle-size distribution from particles from the different parent soils were reasonably close to each other, with those for the Beccles distribution being more variable. There was a significant difference between the two. The strength of the reconstituted Batcombe soil was markedly greater than that of its parent soil, whereas that for Beccles soil was markedly less. There was little difference for the Stackyard soil.The bulk densities of saturated soils reconstituted from all nine fractions could be estimated reasonably accurately from the properties of the separate components. The structure of each of these soils in the air-dry state was inferred from comparisons between measured and calculated bulk densities. The breaking strengths of air-dry reconstituted soils were estimated from the properties of the separate components, and agreed reasonably well with the measured values for soils in which the clay and fine silt fractions predominated.Whereas it was generally possible to predict various physical properties of the reconstituted soils from those of the separate fractions, it was not possible to extrapolate the results to explain field behaviour.

EFFECT OF REVERSE MICELLE WATER POOL IN SYNTHESIS OF ZIRCONIA STABILIZED COPPER NANOCOMPOSITE

2012 ◽  
Vol 05 ◽  
pp. 559-567
Author(s):  
H. Abdizadeh ◽  
Y. Vahidshad ◽  
H. R. Baharvandi ◽  
M. Akbari Baseri
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Physical Properties ◽  
Size Distribution ◽  
Anionic Surfactant ◽  
Reverse Micelle ◽  
Sol Gel ◽  
Molar Ratio ◽  
Water Pool ◽  
20 Nm

In the water-in-oil (W/O) microemulsions based on anionic (AOT) surfactants, the ω value (molar ratio of water to surfactant), precursor, and surfactant could remarkably affect the synthesis of CuO - ZrO 2 nanocomposite and the morphologies of the sol-gel products simultaneously. In this study, CuO - ZrO 2 nanoparticles are synthesized using microreactors made of surfactant/water/n-hexane microemulsions and discusses the effect of different microemulsion variables on the particle size and particle size distribution by water-to-surfactant molar ratio. The obtained powders are characterized by DTA, XRD, SEM, EDS, and TEM and their physical properties are compared. For AOT surfactant the particle size increased with increasing the water to surfactant molar ratio. The particles size of CuO - ZrO 2 nanocomposite in sample with anionic surfactant with molar ratio of 6 that calcined at 600°C is between 15-20 nm.

scholarly journals A study on influence of physical properties of crushed sand with adjusted particle size distribution for fluidity of mortar

◽  
2019 ◽  
Author(s):  
Daijiro Tokunaga ◽  
◽  
Koji Takasu ◽  
Hidehiro Koyamada ◽  
Hiroki Suyama ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Physical Properties ◽  
Size Distribution

Estimation of water holding capacity of soils using data from different types of particle size analyses

2021 ◽  
Author(s):  
Adrienn Horváth ◽  
András Makó ◽  
András Bidló ◽  
Orsolya Szecsődi
Keyword(s):  
Particle Size ◽  
Soil Properties ◽  
Size Distribution ◽  
Clay Fraction ◽  
Laser Diffraction ◽  
Water Holding Capacity ◽  
Extreme Weather Events ◽  
Sedimentation Method ◽  
Pre Treatment ◽  
Water Holding

&lt;p&gt;Determining the particle size distribution of soils helps to monitor the hydrophysical properties of the soil (e.g. water conductivity or water holding capacity). Climate change increases the importance of water retention and permeability, as extreme weather events can severely impair the water supply of drought-prone plant stocks. The amount of water is expected to decrease. At the beginning of the research, we have developed a measurement method to replace the classical &amp;#8220;pipette&amp;#8221; sedimentation method with the laser diffraction method. The theoretical background of laser diffraction measurements is already known, but its practical application for estimating soil&amp;#8217;s water holding capacity is uncommon in detail. The developed, modified Thornthwaite model considers soil properties (e.g. root depth, topsoil layer thickness) and size distribution (silt and clay fraction) of soil particles combined with the most significant soil properties. 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, instrumental measurements (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 that could be a basis for studying the drought sensitivity of soils. By the development of our method, the water holding capacity of soil can be estimated; therefore, adapting forest management could be planned against climatic and pedological transformations.&lt;/p&gt;

Sign in / Sign up

Export Citation Format

Share Document