scholarly journals The Effect of Physical and Hydraulic Properties of Peatmoss and Pumice on Douglas Fir Bark Based Soilless Substrates

HortScience ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 874-878 ◽  
Author(s):  
Magdalena Zazirska Gabriel ◽  
James E. Altland ◽  
James S. Owen
Keyword(s):  
Bulk Density ◽  
Total Porosity ◽  
Douglas Fir ◽  
Available Water ◽  
Air Space ◽  
Secondary Objective ◽  
Common Substrate ◽  
Predicted Values ◽  
The Individual ◽  
Container Capacity

Douglas fir [Pseudotsuga menziesii Mirb. (Franco)] bark (DFB), sphagnum peatmoss, and pumice are the most common substrate components used in the Oregon nursery industry. The objective of this study was to document the effect of peat and pumice addition on the physical and hydrological properties of DFB soilless substrates. A secondary objective was to determine if measured properties of mixed soilless substrates can be accurately predicted from the known properties of the individual components. Treatment design was a 3 × 3 factorial with three rates each of sphagnum peatmoss and pumice (0%, 15%, and 30% by vol.) added to DFB. The resulting nine substrates were measured for total porosity, air space, container capacity, and bulk density using porometers. Moisture characteristic curves were generated by measuring water content along a continuous column. Adding pumice to DFB decreased total porosity, container capacity, available water, and water-buffering capacity but increased bulk density. Adding peatmoss to DFB increased total porosity, container capacity, and available water but decreased air space and bulk density. Comparison of predicted values against measured values indicated that bulk density could be predicted reliably; however, all other physical properties could not be accurately predicted.

scholarly journals Change in Physical Properties of Pine Bark and Switchgrass Substrates Over Time

2012 ◽  
Vol 30 (3) ◽  
pp. 113-117
Author(s):  
James E. Altland ◽  
Charles Krause
Keyword(s):  
Root Growth ◽  
Physical Properties ◽  
Bulk Density ◽  
Total Porosity ◽  
Pine Bark ◽  
Change Over Time ◽  
Air Space ◽  
Over Time ◽  
Container Capacity

Alternatives to pine bark for nursery crop substrates have been proposed, including the use of straw materials such as switchgrass. While straw substrates can be developed with suitable physical properties measured immediately after mixing, little is known about how the physical properties of straw-based substrates change over time. The objective of this research was to measure the change in air space (AS), container capacity (CC), total porosity (TP), and bulk density (Db) over time of a switchgrass-based substrate compared to a pine bark substrate. Switchgrass and pine bark substrates were packed into 15 cm (6 in) tall aluminum cores and placed in a production greenhouse with or without a single hibiscus plant. Physical properties of the substrates were measured at the beginning of the experiment and 9 to 10 weeks later when the plants were nearly too large for their containers. Air space decreased over time, primarily as a function of root growth and shrinkage. Container capacity increased slightly across all treatments over time. Bulk density changed very little over time. The switchgrass substrate was more prone to shrinkage than the pine bark substrate, although vigorous hibiscus root growth reduced shrinkage in switchgrass substrates.

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.

scholarly journals Bulk density and relationship air/water of horticultural substrate

2004 ◽  
Vol 61 (4) ◽  
pp. 446-450 ◽  
Author(s):  
Carolina Fernandes ◽  
José Eduardo Corá
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Total Porosity ◽  
Regression Equations ◽  
Mathematical Functions ◽  
Water Release ◽  
Growing Period ◽  
Available Water ◽  
Particles Size Distribution ◽  
Density Values

Change on substrate bulk density during the growing period may negatively affect other substrate physical properties and, consequently, plant growth. The objectives of this research were 1) to characterize physical properties of two horticultural substrates (S1 and S2), 2) to evaluate the effect of different bulk densities values of those substrates on their air/water relationship, and 3) to develop mathematical functions to estimate the air/water relationship by increasing substrates bulk density value. First, the distribution of particles size, the bulk density, and the water release curve of the substrates were determined. Then, substrates were packed with three different bulk density values, i.e. 10% (D1), 20% (D2) and 30% (D3), higher than the bulk density (D) determined in the characterization phase. The water release curves were determined for each bulk density value of both substrates. The effect of increasing substrate bulk density in the total porosity (TP), aeration space (AS), available water (AW), easily available water (EAW), buffering water (BW), and in the remaining water (RW) was evaluated using simple linear regression and polynomial analysis. The particles size distribution and the water release curves were significantly different for the two substrates. Increasing the bulk density value decreased TP and AS, and increased BW and RW. The highest values of AW and EAW were observed for D1. Regression equations obtained can be used to choose the more appropriate air/water relationship for each growing condition.

scholarly journals Evaluation of Compost as an Amendment to Commercial Mixes used for Container-grown Golden Shrimp Plant Production

2001 ◽  
Vol 11 (1) ◽  
pp. 31-35 ◽  
Author(s):  
S.B. Wilson ◽  
P.J. Stoffella ◽  
D.A. Graetz
Keyword(s):  
Electrical Conductivity ◽  
Bulk Density ◽  
Leaf Area ◽  
Particle Density ◽  
Total Porosity ◽  
Dry Weight ◽  
Plant Production ◽  
Root Dry Weight ◽  
Nitrogen Mobilization ◽  
Container Capacity

Growth of golden shrimp plant (Pachystachys lutea Nees.) transplants was evaluated in media containing 0%, 25%, 50%, 75%, or 100% compost derived from biosolids and yard trimmings. A commercial coir- or peat-based media was amended with compost. As compost composition in the peat or coir-based media increased from 0% to 100%, carbon/nitrogen ratios decreased; and media stability, nitrogen mobilization, pH, and electrical conductivity increased. Bulk density, particle density, air-filled porosity, container capacity, and total porosity increased as more compost was added to either peat- or coir-based media. Plants grown in media with high volumes of compost (75% or 100%) had less leaf area and lower shoot and root dry weight compared to the controls (no compost). Regardless of percentage of compost composition in either peat or coir-based media, all plants were considered marketable after 8 weeks.

scholarly journals Physical Properties of Pine Bark and Hardwood Bark Media and Their Effects with 4 Fertilizers on Growth of llex x ‘Nellie R. Stevens’ Holly

1985 ◽  
Vol 3 (4) ◽  
pp. 181-185
Author(s):  
T.E. Bilderback
Keyword(s):  
Particle Size ◽  
Bulk Density ◽  
Total Porosity ◽  
Dry Weight ◽  
Pine Bark ◽  
Foliar Nitrogen ◽  
Nitrogen Levels ◽  
Air Space ◽  
Retention Characteristics ◽  
Top Dry Weight

Pine bark (PB) and composted hardwood bark (HWB) were combined into 5 media. Particle size distribution, total porosity, air space, moisture retention characteristics, and bulk density were determined for each medium. Four commercial fertilizers were applied and substrate nitrogen levels, pH, % foliar nitrogen and top dry weight were determined for Ilex x ‘Nellie R. Stevens’ holly. Pine bark had approximately 84% of the particles between 4.75 and 1.0 mm (0.19 and 0.04 in). As HWB was added in 25% increments (by vol) the percent weight of particles in this range decreased. HWB increased bulk density, but did not significantly change total porosity. Hardwood bark and the 1:3 PB:HWB (v/v) medium held more water than other media. Nursery Special raised pH in all media treatments. Plants treated with SulfurKote tended to have the highest foliar nitrogen content. The Sierrablen in PB and SulfurKote in 3 PB:1 HWB and 1 PB:1 HWB (v/v) and HWB produced the greatest top dry weight.

scholarly journals Physical Properties of Container Media and Relation to Severity of Phytophthora Root Rot of Rhododendron

1990 ◽  
Vol 115 (4) ◽  
pp. 564-570 ◽  
Author(s):  
B.H. Ownley ◽  
D.M. Benson ◽  
T. E. Bilderback
Keyword(s):  
Bulk Density ◽  
Root Rot ◽  
Phytophthora Cinnamomi ◽  
Total Porosity ◽  
Pine Bark ◽  
Phytophthora Root Rot ◽  
Air Space ◽  
The Media ◽  
One Year ◽  
Water Percent

One-year-old Rhododendron L. `Nova Zembla' were grown in four container media infested with Phytophthora cinnamomi Rands. The media (all v/v) were pine bark, 3 pine bark:1 sand, 3 pine bark:1 peat, and 1 peat: 1 sand: 1 soil. After 20 weeks, plants were evaluated for root rot symptoms and the total porosity, air space, moisture-holding capacity, and bulk density were determined for all media. All media provided adequate moisture-holding capacity for container production of rhododendron in noninfested media. Shoot fresh weight in noninfested media was positively correlated with bulk density and water (percent by volume) held in the 1.0- to 5.0-kPa matric tension range and negatively correlated with total porosity and air space. Root rot severity was greatest in peat: sand: soil, intermediate in pine bark: peat, and least in pine bark and pine bark: sand. Root rot severity was negatively correlated with total porosity and air space and positively correlated with bulk density and water (percent by volume) held in the 5.0- to 10.0-kPa matric tension range.

scholarly journals KAJIAN SIFAT FISIKA EMPAT TANAH UTAMA DI SUMATERA BARAT

Jurnal Solum ◽  
2007 ◽  
Vol 4 (2) ◽  
pp. 81
Author(s):  
Yulnafatmawita Yulnafatmawita ◽  
Asmar Asmar ◽  
Ari Ramayani
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Bulk Density ◽  
Organic Matter Content ◽  
Total Porosity ◽  
Matter Content ◽  
Available Water ◽  
Physical Study ◽  
West Sumatra ◽  
Plant Available Water

A research about soil physical study of four main soils found in West Sumatra was conducted in 2006.  The research was aimed to determine some soil physical properties of four soil which are mostly found in West Sumatra.  The four soil orders assessed were Ultisol from Agricultural Expreriment Station Limau Manis, Oxisol from Lubuk Minturun, Entisol from Tabing Kecamatan Koto Tangah Padang, dan Andisol from Bukik Gompong Kabupaten Solok.  The result showed that at the depth of 0-20 cm soil profile.  Ultisol and Oxisol had finer texture than those of Andisol and Entisol.  Andisol was dominated by silt while Entisol was dominated by sand particles.  Andisol had the lowest bulk density and the highest soil organic matter and total porosity.  Soil Organic matter content of Entisol, Oxisol, and Ultisols was low in criteria.  Plant available water (PAW) was higher in Oxisol, then followed by Andisol, Ultisol, and Entisol.Key words: Organic matter, bulk density, texture, porosity, plant available water

scholarly journals A NEW METHOD FOR MEASURING TOTAL POROSITY IN HORTICULTURAL SUBSTRATES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1093c-1093
Author(s):  
William C. Fonteno
Keyword(s):  
Bulk Density ◽  
Particle Density ◽  
Total Porosity ◽  
Great Accuracy ◽  
Modified Method ◽  
New Apparatus ◽  
The Difference ◽  
Mineral Soils ◽  
Container Capacity

The determination of air and water holding capacities of horticultural substrates has been plagued by errors in measurement. The amount of air and water held at container capacity is influenced by the substrate and container height. Container capacity can be established through specific measurement. Air space, the difference between total porosity and container capacity, is usually poorly determined because of errors in total porosity measurement. Most researchers calculate total porosity (St) from the formula: St = 1-(ρb/ρp), where ρb is the dry bulk density and ρp is the particle density. While bulk density is usually measured, particle density is not. Many times an average ρp of 2.65 Mg·m-3 for mineral soils is used. This sometimes creates large errors in calculating total porosity because the values of ρp for horticultural substrates range from 0.35 to 2.1 Mg·m-3. Total porosity can be measured with great accuracy at 0 kPa tension on a pressure plate apparatus, but is costly in equipment and time. Using a modified method of extraction and a new apparatus, using standard aluminum soil sampling cylinders, total porosity was measured with an 85% reduction in time end no decrease in accuracy.

scholarly journals A Comparison of WholeTree and Chipped Pine Log Substrate Components in the Production of Greenhouse Grown Annuals

2010 ◽  
Vol 28 (3) ◽  
pp. 173-178
Author(s):  
Whitney G. Gaches ◽  
Glenn B. Fain ◽  
Donald J. Eakes ◽  
Charles H. Gilliam ◽  
Jeff L. Sibley
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Pinus Taeda ◽  
Catharanthus Roseus ◽  
Total Porosity ◽  
Dry Weight ◽  
Air Space ◽  
Pine Trees ◽  
Impatiens Walleriana ◽  
Pinus Taeda L

Abstract WholeTree (WT) and chipped pine logs (CPL) are potential new sustainable greenhouse substrate components made by milling chipped pine trees and/or pine logs (Pinus taeda L.). Two experiments were conducted to evaluate the growth of Catharanthus roseus L. ‘Grape Cooler’ and Impatiens walleriana Hook.f. ‘Dazzler Apricot’ in 1:1 (v:v) WT:peat (WTP) and 1:1 (v:v) CPL:peat (CPLP), and to compare physical properties of those substrates. In Experiment 1 WTP had 76.8% container capacity (CC) and 96.4% total porosity (TP) while CPLP had 72.4% CC and 90% TP; air space (AS) and bulk density (BD) were similar. In Experiment 2 there were no differences in physical properties. In Experiment 1 EC peaked at 14 days after potting (DAP) and decreased through the remainder of the study. At 0 DAP pH ranged from 4.2–4.3 and increased to a range of 6.4 to 6.8 at 42 DAP. This trend was similar in Experiment 2, except that EC peaked at 7 DAP. In impatiens, plants were similar in Experiment 1 but those grown in WTP in Experiment 2 had bloom counts of 37.3 compared to 27.9 for plants grown in CPLP. With vinca, in Experiment 1 plants grown in CPLP had a dry weight of 7.3 g as compared to 6.9 g for plants grown in WTP, but there were no differences in Experiment 2. Results indicate that growers could use CPL and/or WT interchangeably, depending on available resources.

scholarly journals A Rapid Method for Determining Physical Properties of Undisturbed Substrate

HortScience ◽  
1992 ◽  
Vol 27 (12) ◽  
pp. 1279-1280 ◽  
Author(s):  
Carl E. Niedziela ◽  
Paul V. Nelson
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Rapid Method ◽  
Particle Density ◽  
Total Porosity ◽  
Container Capacity

A new tube method for determining physical properties in container substrates was compared to an existing system. While both offer the advantages of undisturbed substrate and measurement of properties without altering the geometry of the substrate in the container, the tube method is easier to conduct. Both methods proved equally effective for determining air-tilled porosity, container capacity, total porosity, bulk density, and particle density.

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