scholarly journals WATER RETENTION IN SOILLESS POTTING MEDIA

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1099G-1099
Author(s):  
George C. Elliott
Keyword(s):  
Water Retention ◽  
Wetting Agent ◽  
Irrigation Method ◽  
Polymeric Gel ◽  
Potting Media ◽  
Daily Water ◽  
Irrigation Treatments ◽  
Hydrophilic Gel ◽  
Measured Water

Water retention was measured in soilless potting media irrigated by capillary mat, flood and drain, drip or overhead sprinkler. Media were amended with wetting agent or hydrophilic polymeric gel. Pots 12 cm high with a volume of 465 cm3 were loose-filled to the top with media. Potted media were wetted overhead with 120 ml water, then pots were randomly assigned to irrigation treatments. Capillary mat irrigation was continuous; other irrigation treatments were applied daily. Water retention was measured by weighing. Irrigation was continued until no further retention was measured. Water retention was significantly affected by irrigation method and medium amendments. Irrigation method followed the order overhead >= drip > flood and drain >= mat. Hydrophilic gel increased water retention, but in contrast to previous results, wetting agent did not, nor was any interaction of gel and wetting agent observed. Retention of water at container capacity, measured in situ at the end of each experiment, was significantly larger than actual retention.

WATER RETENTION IN SOILLESS POTTING MEDIA

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1099g-1099
Author(s):  
George C. Elliott
Keyword(s):  
Water Retention ◽  
Wetting Agent ◽  
Irrigation Method ◽  
Polymeric Gel ◽  
Potting Media ◽  
Daily Water ◽  
Irrigation Treatments ◽  
Hydrophilic Gel ◽  
Measured Water

Water retention was measured in soilless potting media irrigated by capillary mat, flood and drain, drip or overhead sprinkler. Media were amended with wetting agent or hydrophilic polymeric gel. Pots 12 cm high with a volume of 465 cm3 were loose-filled to the top with media. Potted media were wetted overhead with 120 ml water, then pots were randomly assigned to irrigation treatments. Capillary mat irrigation was continuous; other irrigation treatments were applied daily. Water retention was measured by weighing. Irrigation was continued until no further retention was measured. Water retention was significantly affected by irrigation method and medium amendments. Irrigation method followed the order overhead >= drip > flood and drain >= mat. Hydrophilic gel increased water retention, but in contrast to previous results, wetting agent did not, nor was any interaction of gel and wetting agent observed. Retention of water at container capacity, measured in situ at the end of each experiment, was significantly larger than actual retention.

scholarly journals Imbibition of Water by Rockwool-Peat Container Media Amended with Hydrophilic Gel or Wetting Agent

1992 ◽  
Vol 117 (5) ◽  
pp. 757-761 ◽  
Author(s):  
George C. Elliott
Keyword(s):  
Water Retention ◽  
Rank Order ◽  
Sprinkler Irrigation ◽  
Wetting Agent ◽  
Free Drainage ◽  
Potting Media ◽  
Hydrophilic Gel ◽  
Water Holding ◽  
Effective Water ◽  
Overhead Sprinkler

Water retention at effective water-holding capacity (EWHC) and container capacity (CCAP) were measured in four rockwool-peat potting media amended with a wetting agent and/or a hydrophilic gel in pots 12 cm tall containing 445 cm3 medium, and irrigated by capillary mat, flood-and-drain, trickle emitter, or overhead sprinkler. Water retention was measured by weighing. Irrigation was continued until EWHC (i.e., net water retention when no weight increase could be obtained by further irrigation) was reached. CCAP (i.e., net water retention following saturation and free drainage) was measured at the end of each experiment. Irrigation method and medium amendments significantly affected EWHC. Rank order of irrigation treatments was sprinkler ≥ trickle > flood and drain ≥ mat. Hydrophilic gel increased both EWHC and CCAP, while the wetting agent increased EWHC but decreased or had no effect on CCAP. Significant interactions of gel and wetting agent were observed in some media. EWHC was less than CCAP, and EWHC was better correlated with CCAP with trickle emitter and overhead sprinkler irrigation than with capillary mat and flood-and-drain irrigation.

scholarly journals Wetting Characteristics of Different Peat and Peat: Bark-based Potting Media: Influence of Wetting Agents in Improving Wetting and Rewetting Performance

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 583f-584
Author(s):  
Santakumari Mane ◽  
James A. Turner
Keyword(s):  
Water Retention ◽  
Unit Volume ◽  
Initial Moisture Content ◽  
Wetting Agent ◽  
Media Composition ◽  
Potting Media ◽  
The Media ◽  
Wetting Agents ◽  
Reduced Water ◽  
Agent Treatment

Eight different peat-based or peat: bark-based potting media were evaluated for their wetting performance when treated with the media wetting agent AquaGro 2000 (2–5 oz/yd3). Upon initial irrigation, no differences in wetting uniformity were observed in seven of the eight test media regardless of their media wetting agent treatments. In four media, water retention was reduced by media wetting agent treatment, however, uniform distribution of water was achieved. AquaGro 2000 improved uniformity of initial wetting in one medium in which the initial moisture content was 6.5%. Uniformity of wetting and water retention improved with increasing wetting agent rate. All media were allowed to air dry and then were re-irrigated. Wetting agent-treated media rewet uniformly, while rewetting varied greatly in untreated media (7.5%–82.5%). Less than 50% of the mass of untreated media wet subsequent to drying. Those portions of the untreated media that did wet retained up to three times more water per unit volume compared to AquaGro 2000-treated media. AquaGro 2000 enhanced uniformity of rewetting, reduced water logging, and improved drainage at all rates (2–5 oz/yd3) tested. Media composition (peat vs. peat: bark did not affect wetting agent efficacy.

Repeatability, Reproducibility, and Calibration of the MyotonPro® on Tissue Mimicking Phantoms

2013 ◽  
Author(s):  
John Dougherty ◽  
Emily Schaefer ◽  
Kalyani Nair ◽  
Joseph Kelly ◽  
Alfonse Masi
Keyword(s):  
Data Collection ◽  
Dynamic Stiffness ◽  
Correlation Study ◽  
Living Tissue ◽  
Polymeric Gel ◽  
Stiffness Properties ◽  
Tissue Phantoms ◽  
Repeatability And Reproducibility ◽  
Living Tissues

The MyotonPro® (Myoton AS, Tallinn, Estonia) is commonly used to quantify stiffness properties of living tissues in situ. Current studies quantify the dynamic stiffness properties of living tissues, but do not validate or compare these measurements to a standardized method. Additionally, living tissue, being dynamic in nature, presents much variability in data collection. To address these issues this study focuses on the repeatability and reproducibility of the MyotonPro® on polymeric gel-based tissue phantoms. In addition, a correlation study is also performed to translate dynamic stiffness to a more standardized property, Young’s modulus. Such studies help to confirm the reliability of the measurements obtained in situ.

scholarly journals Changes in the reserves of soil retention of arable lands in Central Sudety

2007 ◽  
Vol 38 (1) ◽  
pp. 33-40
Author(s):  
Grzegorz Pęczkowski ◽  
Stanisław Kostrzewa ◽  
Wojciech Orzepowski
Keyword(s):  
Cross Section ◽  
Water Retention ◽  
Vegetation Period ◽  
Meteorological Conditions ◽  
Soil Profiles ◽  
Water Supplies ◽  
Analysis And Evaluation ◽  
Water Capacity ◽  
Soil Retention ◽  
Measured Water

Changes in the reserves of soil retention of arable lands in Central Sudety The project presents research involving an analysis and evaluation of water supply of poorly permeable soils in drained arable lands. The analysis dealt with research conducted in 2003-2005 at similar meteorological conditions in an agricultural submountain catchment area situated in Central Sudety. In particular, the analysis concerned water and air properties of examined deposits with regard to their water-retention. The measurements of moisture density of soil profiles and calculated water supplies in layers 1-100 cm showed a cross-section of reserves of soil retention. This depended on the depth and lay of the land as well as drainage conditions. In the lower drainage area at the foot of the slope there was a notably higher level of groundwater than in other places on the slope. In areas where rainfall was the exclusive source of groundwater the measured water-supplies were lower than in multi-sourced drainage areas. The amount of measured supplies for the vegetation period spanning the whole research time was not lower than 70% of the field-water capacity.

scholarly journals A Novel Frequency Domain Impedance Sensor with a Perforated Cylinder Coaxial Design for In-Situ Measuring Soil Matric Potential

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2626 ◽  
Author(s):  
Chao Chen ◽  
Xiaofei Yan ◽  
Qiang Xu ◽  
Song Yu ◽  
Yihan Ma ◽  
...  
Keyword(s):  
Water Content ◽  
Water Retention ◽  
Soil Samples ◽  
Environmental Research ◽  
Water Retention Curve ◽  
The Novel ◽  
Soil Matric Potential ◽  
Matric Potential ◽  
Retention Curve

Soil matric potential is an important parameter for agricultural and environmental research and applications. In this study, we developed a novel sensor to determine fast and in-situ the soil matric potential. The probe of the soil matric potential sensor comprises a perforated coaxial stainless steel cylinder filled with a porous material (gypsum). With a pre-determined gypsum water retention curve, the probe can determine the gypsum matric potential through measuring its water content. The matric potential of soil surrounding the probe is inferred by the reading of the sensor after the soil reaches a hydraulic equilibrium with the gypsum. The sensor was calibrated by determining the gypsum water retention curve using a pressure plate method and tested in three soil samples with different textures. The results showed that the novel sensor can determine the water retention curves of the three soil samples from saturated to dry when combined with a soil water content sensor. The novel sensor can respond fast to the changes of the soil matric potential due to its small volume. Future research could explore the application for agriculture field crop irrigation.

Evaluation of physical properties of several growing media for use in aerial seeding containers

1987 ◽  
Vol 17 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Tanya L. Lennox ◽  
Glen P. Lumis
Keyword(s):  
Water Retention ◽  
Total Porosity ◽  
Linear Increase ◽  
Buffering Capacity ◽  
Tree Seedlings ◽  
Growing Media ◽  
Available Water ◽  
Air Space ◽  
The Media ◽  
Hydrophilic Gel

Several personally blended and commercially prepared growing media were evaluated as potential substrates for coniferous tree seedlings in specialized seeding containers (aerial darts). Water retention curves were developed using a porous pressure plate apparatus. Bark–vermiculite–sand and Ball Growing Mix II retained less water at pressures from 0 to 0.1 MPa than all other media observed. At pressures less than 20 × 10−3 MPa the greatest water retention was in Pro-mix A, while above 33 × 10−3 MPa the greatest water retention was in bark–vermiculite. As the proportion of bark in bark–vermiculite was increased, the air space increased significantly but water retention was unaffected. Addition of a hydrophilic gel to media containing a surfactant significantly increased water retention. The easily available water, water buffering capacity, and air space were unaffected by gel but total porosity increased in some of the media. When the surfactant was excluded the addition of gel at the recommended rate did not significantly increase water retention. As the concentration of gel increased there was an increase in water retention, a linear increase in total porosity, a slight increase in air space, a decrease in easily available water, and no change in water buffering capacity. Media amended with gels of different absorbing capacities retained water similarly, releasing approximately 50% of the absorbed water at pressures less than 10 × 10−3 MPa.

Design of a hierarchically structured hybrid material via in situ assembly of a silica aerogel into a wood cellular structure

RSC Advances ◽  
2016 ◽  
Vol 6 (67) ◽  
pp. 62825-62832 ◽  
Author(s):  
M. Sedighi Gilani ◽  
S. Zhao ◽  
S. Gaan ◽  
M. M. Koebel ◽  
T. Zimmermann
Keyword(s):  
Thermal Conductivity ◽  
Hybrid Material ◽  
Dimensional Stability ◽  
Silica Aerogel ◽  
Cellular Structure ◽  
Water Retention ◽  
Heat Of Combustion ◽  
Structure Modification ◽  
Reduced Water

We present a route for incorporation of silica aerogel into wood cellular structure. Modification results in an improved dimensional stability and reduced water retention of the material, with lower thermal conductivity and total heat of combustion.

scholarly journals Hydrogels Improve Plant Growth in Mars Analog Conditions

2021 ◽  
Vol 8 ◽  
Author(s):  
Frédéric Peyrusson
Keyword(s):  
Plant Growth ◽  
Food Production ◽  
Water Retention ◽  
Organic Matter Content ◽  
Matter Content ◽  
Research Station ◽  
Soil Water Retention ◽  
Mentha Spicata ◽  
Potting Medium

Sustainable human settlement on Mars will require in situ resource utilization (ISRU), the collection and utilization of Mars-based resources, including notably water and a substrate for food production. Plants will be fundamental components of future human missions to Mars, and the question of whether Mars soils can support plant growth is still open. Moreover, plant cultivation may suffer from the lack of in situ liquid water, which might constitute one of the biggest challenges for ISRU-based food production on Mars. Enhancing the crop yield with less water input and improving water utilization by plants are thus chief concern for sustainable ISRU food production. Hydrogels are polymers able to absorb large quantity of water and to increase soil water retention, plant establishment and growth. This work reports on the short-term assessment of plant growth in Mars soil analogs supplemented with hydrogels. Soil analogs consisted of sand and clay-rich material, with low organic matter content and alkaline pH. Soils were supplemented with 10% (w/w) potting medium and were sampled in Utah desert, in the vicinity of the Mars Desert Research Station, surrounded by soils sharing similarities in mineralogical and chemical composition to Martian soils. Height and dry biomass of spearmint (Mentha spicata) were compared under various irrigation frequencies, and seed germination of radish (Raphanus sativus) were monitored. Under limited irrigation, results indicate that the soil analogs were less capable of supporting plant growth as a comparison to potting medium. The effects of hydrogel supplementation were significant under limited irrigation and led to spearmint heights increased by 3 and 6% in clay- and sand-containing soils, respectively. Similarly, hydrogel supplementation resulted in spearmint mass increased by 110% in clay-containing soils and 78% in sand-containing soils. Additionally, while radish seeds failed to germinate in soil analogs, hydrogel supplementation allows for the germination of 27% of seeds, indicating that hydrogels might help loosening dense media with low water retention. Collectively, the results suggest that supplementation with hydrogel and plant growth substrate could help plants cope with limited irrigation and poor alkaline Mars soil analogs, and are discussed in the context of strategies for ISRU-based off-world colonization.

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