scholarly journals Physical Properties of Sphagnum Peat-based Root Substrates Amended with Perlite or Parboiled Fresh Rice Hulls

2007 ◽  
Vol 17 (3) ◽  
pp. 312-315 ◽  
Author(s):  
Michael R. Evans ◽  
Mary M. Gachukia
Keyword(s):  
Physical Properties ◽  
Pore Space ◽  
Water Holding Capacity ◽  
Practical Significance ◽  
Equivalent Amount ◽  
Rice Hulls ◽  
Sphagnum Peat ◽  
Rate Of Increase ◽  
Water Holding

Ten substrates were formulated by blending perlite or parboiled fresh rice hulls (PBH) to produce root substrates (substrates) that contained either 20%, 30%, 40%, 50%, or 60% (by volume) perlite or PBH, with the remainder being sphagnum peatmoss. All substrates containing PBH had higher total pore space than substrates containing an equivalent amount of perlite. As the percentage perlite increased from 20% to 60%, the total pore space decreased. The total pore space increased as the amount of PBH increased to 50% and then decreased as the amount of PBH increased from 50% to 60%. The air-filled pore space was not different between substrates containing 20% perlite or PBH. However, the air-filled pore space was higher in PBH-containing substrates than in equivalent perlite-containing substrates when the amount of PBH or perlite was at least 40%. As the amount of perlite or PBH was increased, the air-filled pore space increased, but the rate of increase was higher for PBH-containing substrates. The 20% PBH-containing substrate had a higher water-holding capacity than the 20% perlite-containing substrate. However, at 30% or higher PBH, the PBH-containing root substrates had a lower water-holding capacity than equivalent perlite-containing substrates. As the percentage perlite or PBH was increased, the water-holding capacity decreased, but at a higher rate in PBH-containing substrates than in perlite-containing substrates. For all substrates except those containing 40% PBH or perlite, substrates containing PBH had lower bulk densities than equivalent perlite-containing substrates. The differences in bulk densities were not great enough to be of practical significance. Inclusion of PBH in the substrate provided for drainage and air-filled pore space as did perlite. However, less PBH would be required in a substrate to provide the same air-filled pore space as perlite when more than 20% perlite or PBH is used.

scholarly journals Physical Properties of and Plant Growth in Peat-based Root Substrates Containing Glass-based Aggregate, Perlite, and Parboiled Fresh Rice Hulls

2011 ◽  
Vol 21 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Michael R. Evans
Keyword(s):  
Plant Growth ◽  
Physical Properties ◽  
Bulk Density ◽  
Catharanthus Roseus ◽  
Pore Space ◽  
Santa Fe ◽  
Rice Hulls ◽  
Sphagnum Peat ◽  
Impatiens Walleriana ◽  
Water Holding

Aggregates produced from finely ground waste glass [Growstones (GS); Earthstone Corp., Santa Fe, NM] have been proposed to adjust the physical properties of peat-based substrates. The GS had a total pore space (TPS) of 87.4% (by volume), which was higher than that of sphagnum peat and perlite but was similar to that of parboiled fresh rice hulls (PBH). The GS had an air-filled pore space (AFP) of 53.1%, which was higher than that of sphagnum peat and perlite but lower than that of PBH. At 34.3%, GS had a lower water-holding capacity (WHC) than sphagnum peat but a higher WHC than either perlite or PBH. The bulk density of GS was 0.19 g·cm−3 and was not different from that of the perlite but was higher than that of sphagnum peat and PBH. The addition of at least 15% GS to sphagnum peat increased the AFP of the resulting peat-based substrate. Substrates containing 25% or 30% GS had a higher AFP than substrates containing equivalent amounts of perlite but a lower AFP than substrates containing equivalent PBH. Substrates containing 20% or more GS had a higher WHC than equivalent perlite- or PBH-containing substrates. Growth of ‘Cooler Grape’ vinca (Catharanthus roseus), ‘Dazzler Lilac Splash’ impatiens (Impatiens walleriana), and ‘Score Red’ geranium (Pelargonium ×hortorum) was similar for plants grown in GS-containing substrates and those grown in equivalent perlite- and PBH-containing substrates.

scholarly journals Physical Properties of Processed Poultry Feather Fiber-containing Greenhouse Root Substrates

2007 ◽  
Vol 17 (3) ◽  
pp. 301-304 ◽  
Author(s):  
Michael R. Evans ◽  
Leisha Vance
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Pore Space ◽  
Water Holding Capacity ◽  
Pine Bark ◽  
Sphagnum Peat ◽  
The Difference ◽  
Poultry Feather ◽  
Feather Fiber ◽  
Water Holding

A series of soilless root substrates was formulated to contain either 20% composted pine bark or perlite and 0%, 10%, 20%, or 30% feather fiber, with the remainder being sphagnum peat. The substrates containing bark or perlite with 0% feather fiber served as the controls for the bark- and perlite-containing substrates respectively. For root substrates containing perlite, the inclusion of feather fiber increased the total pore space compared with the control substrate. For substrates containing bark, the inclusion of 10% or 20% feather fiber increased total pore space, but the inclusion of 30% feather fiber reduced total pore space. For substrates containing perlite, the inclusion of feather fiber increased the air-filled pore space compared with the control, and as the percentage feather fiber increased, air-filled pore space increased. For substrates containing bark, the inclusion of 10% or 20% feather fiber increased air-filled pore space, but air-filled pore space of the substrate containing 30% feather fiber was not different from the control. For all substrates, the inclusion of feather fiber reduced the water-holding capacity, but water-holding capacities for all substrates remained within recommended ranges. The bulk density of feather fiber-containing substrates was not different from the control except for the substrate containing 30% feather fiber with bark, which had a higher bulk density than its control without feather fiber. The difference in physical properties of the 30% feather fiber substrate with bark from its control substrate was attributed to the aggregation of the feather fiber when formulated with composted bark. Aggregation of feather fiber when blended into substrates at levels of 30% or higher would create difficulties in achieving uniform substrates.

scholarly journals Physical Properties of Whole Fresh-ground Parboiled Rice Hulls for Use as a Horticultural Root Substrate

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 979B-979
Author(s):  
Johann S. Buck ◽  
Michael R. Evans ◽  
Paolo Sambo
Keyword(s):  
Plant Growth ◽  
Physical Properties ◽  
Bulk Density ◽  
Pore Space ◽  
Water Holding Capacity ◽  
Rice Hull ◽  
Particle Sizes ◽  
Parboiled Rice ◽  
Rice Hulls ◽  
Water Holding

Horticultural root substrates are designed to provide the optimal physical properties for plant growth. These properties include bulk density (g·cm-3), air-filled pore space (% v/v), total pore space (% v/v), water-filled pore space (% v/v), water-holding capacity (% v/v and w/w), and wettability. Whole, fresh parboiled rice hulls were ground to produce four grades with varying particle size distributions. Particle sizes for the four grades ranged from <0.25 to >2.80 mm. Additionally, discrete particle sizes of <0.25, 0.50, 1.00, 2.00, 2.80, and >2.80 mm were produced. For all grade distributions and particle point sizes, physical properties were determined and contrasted against Canadian sphagnum peat. As the proportion of smaller particle sizes in the distributions increased or as the particle point sizes decreased, total pore space (% v/v) and air-filled pore space (% v/v) decreased, while, bulk density (g·cm-3) and water-holding capacity (% v/v and w/w) increased. Additionally, as the proportion of particle sizes from <0.25–0.50 mm increased, the wettabilty of the whole fresh parboiled rice hull material decreased. Particle sizes ranging from 1.00–2.80 mm possessed the physical properties most suitable for plant growth in containerized greenhouse crop production and were most similar to peat.

scholarly journals Physical Properties of Ground Fresh Rice Hulls and Sphagnum Peat Used for Greenhouse Root Substrates

2008 ◽  
Vol 18 (3) ◽  
pp. 384-388 ◽  
Author(s):  
Paolo Sambo ◽  
Franco Sannazzaro ◽  
Michael R. Evans
Keyword(s):  
Oryza Sativa ◽  
Physical Properties ◽  
Water Content ◽  
Pore Space ◽  
Rice Hull ◽  
Water Release ◽  
Rice Hulls ◽  
Available Water ◽  
Available Water Content ◽  
Water Holding

Ground fresh rice (Oryza sativa) hull materials were produced by grinding whole fresh rice hulls and passing the resulting product through a 1-, 2-, 4- or 6-mm-diameter screen to produce a total of four ground rice products (RH1, RH2, RH4, and RH6, respectively). The physical properties and water release characteristics of sphagnum peatmoss (peat) and the four ground rice hull products were evaluated. All of the ground rice hull products had a higher bulk density (Bd) than peat, and as the grind size of the rice hull particle decreased, Bd increased. Peat had a higher total pore space (TPS) than all of the ground rice hull products except for RH6. As grind size decreased, the TPS decreased. Peat had a lower air-filled pore space (AFP) than all of the ground rice hull products and as the grind size of the rice hull products decreased, AFP decreased. Peat had a higher water holding capacity (WHC) than all of the ground rice hull products. Grind sizes RH4 and RH6 had similar WHC, whereas RH1 and RH2 had a higher WHC than RH4 and RH6. Peat, RH4, and RH6 had similar available water content (AVW), whereas RH2 had higher AVW than these materials and RH1 had the highest AVW. However, peat had the lowest AVW and easily available water (EAW) as a percentage of the WHC. The ground rice hull products RH1 and RH2 had the highest AVW and EAW of the components tested. Peat had the highest water content at container capacity. As pressure was increased from 1 to 5 kPa, peat released water more slowly than any of the ground rice hull products. The RH1 and RH2 ground hull products released water at a significantly higher rate than peat, but RH4 and RH6 released the most water over these pressures. For all rice hull products, most water was released between 1 and 2 kPa pressure. The rice hull products RH1 and RH2 had physical properties that were within recommended ranges and were most similar to those of peat.

scholarly journals Physical Properties of Ground Parboiled Fresh Rice Hulls Used as a Horticultural Root Substrate

HortScience ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 643-649 ◽  
Author(s):  
Johann S. Buck ◽  
Michael R. Evans
Keyword(s):  
Physical Properties ◽  
Particle Density ◽  
Pore Space ◽  
Pine Bark ◽  
Rice Hull ◽  
Hammer Mill ◽  
Parboiled Rice ◽  
Greenhouse Crops ◽  
Rice Hulls ◽  
Water Holding

Fresh parboiled rice hulls ground in a hammer mill and screened through a 1.18-mm screen and collected on a 0.18-mm screen (RH3) and particles with a specific diameter of 0.5 to 1.0 mm had total pore space (TPS), air-filled pore space (AFP), and water-holding capacity (WHC) similar to that of Canadian sphagnum peat (peat). However, RH3 had more available water, a higher bulk density (BD), and a higher particle density (PD) than peat. When blended with 20% to 40% perlite or 1 cm aged pine bark, RH3-based substrates had lower TPS, similar AFP, and lower WHC than equivalent peat-based substrates. The RH3-containing substrates had higher BD and average PD than equivalent peat-based substrates. When blended with parboiled rice hulls (PBH), RH3-based substrates had lower TPS than equivalent peat-based substrates. When blended with 20% to 40% PBH, RH3-based substrates had lower AFP than equivalent peat-based substrates. RH3-based substrates containing up to 20% PBH had lower WHC than equivalent peat-based substrates. RH3-based substrates containing 40% PBH had a higher WHC than equivalent peat-based substrates. When blended with PBH, all RH3-based substrates had higher BD and average PD than equivalent peat-based substrates. The addition of 40% RH3 to a peat-based substrate containing 20% perlite decreased substrate TPS, whereas the addition of 10% to 40% decreased AFP. The addition of 10% to 30% RH3 increased WHC. The addition of 30% RH3 to a peat-based substrate containing 20% 1 cm aged pine bark decreased substrate TPS and the addition of 20% to 40% RH3 decreased AFP. The addition of 10% RH3 increased WHC, but the addition of 20% or more RH3 did not affect WHC. The addition of 30% RH3 increased the BD, but the addition of RH3 had no effect on average PD. The addition of 20% or more and 30% or more RH3 to a peat-based substrate containing 20% PBH decreased substrate TPS and AFP, respectively. The addition 20% RH3 decreased WHC. The addition of 10% to 40% RH3 increased BD. Overall, RH3 was the ground rice hull product that had physical properties most similar to peat. Peat-based substrates in which up to 40% of the peat was replaced with RH3 had physical properties that, although different from peat controls, were within commonly recommended ranges for substrates used to grow greenhouse crops.

scholarly journals Growth of Two Subtropical Ornamentals Using Coir (Coconut Mesocarp Pith) as a Peat Substitute

HortScience ◽  
1994 ◽  
Vol 29 (12) ◽  
pp. 1484-1486 ◽  
Author(s):  
Alan W. Meerow
Keyword(s):  
Growth Index ◽  
Dry Weight ◽  
Water Holding Capacity ◽  
Sphagnum Peat ◽  
Coir Dust ◽  
Top Dry Weight ◽  
Water Holding ◽  
Ixora Coccinea ◽  
Coconut Mesocarp ◽  
Over Time

Growth of Pentas lanecolata (Forssk.) Deflers `Starburst Pink' and Ixora coccinea L. `Maui' was compared in container media using sphagnum peat, sedge peat, or coir dust as their peat components. Growth index and top and root dry weights of both crops were significantly better in coir-based medium than sedge peat-based medium. Pentas grew equally well in coir- and sphagnum peat-based medium. Growth index and top dry weight of Ixora were significantly lower in the coir-based than the sphagnum peat-based medium, although root dry weights were equal. This difference was not apparent and may have been caused by N drawdown in the coir-based mix. The sedge peat-based medium had the highest air porosity and the lowest water-holding capacity of the three media at the initiation of the trials, but at the termination of the study, it showed a reversal of these characteristics. The coir-based medium showed the least change in these attributes over time. Coir dust seems to be an acceptable substitute for sphagnum or sedge peat in soilless container media, although nutritional regimes may need to be adjusted on a crop-by-crop basis.

scholarly journals KENAF PITH AS A VERMICULITE SUBSTITUTE IN PEAT-BASED MEDIA.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 647g-647
Author(s):  
Brad B. Hawcroft ◽  
Steven E. Newman
Keyword(s):  
Pore Space ◽  
Hibiscus Cannabinus ◽  
Peat Moss ◽  
Kenaf Fiber ◽  
Fiber Core ◽  
Sphagnum Peat ◽  
Sphagnum Peat Moss ◽  
Celosia Argentea ◽  
The Media ◽  
Water Holding

Kenaf is an alternative fiber crop being evaluated in Mississippi. Kenaf, primarily grown in Asia, can be used in the manufacture of paper, fiber board, acoustical tiles and compost. The bark is the source of the fiber used, leaving the fiber core or pith for use as a paper additive, poultry litter, or is discarded. The objective of this study was to evaluate the potential use of kenaf fiber core as a vermiculite substitute in a sphagnum peat moss-based medium. Plugs of Celosia argentea, Viola × wittrockiana, and Impatiens wallerana were transplanted into 10 cm pots containing 5 different sphagnum peat moss-based media modified with the milled fiber core (pith) of kenaf (Hibiscus cannabinus) and/or vermiculite. The media were as follows: 5 peat: 0 kenaf : 5 vermiculite (v/v/v); 5 peat : 1 kenaf : 4 vermiculite (v/v/v); 5 peat : 2 kenaf : 3 vermiculite (v/v/v); 5 peat : 3 kenaf : 2 vermiculite (v/v/v); 5 peat : 4 kenaf : 1 vermiculite (v/v/v); and 5 peat : 5 kenaf: 0 vermiculite (v/v/v). Water holding capacity, pore space, pH and media shrinkage were monitored throughout the study along with plant growth and plant quality.

scholarly journals Coconut Husk and Processing Effects on Chemical and Physical Properties of Coconut Coir Dust

HortScience ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 88-90 ◽  
Author(s):  
Sreenivas Konduru ◽  
Michael R. Evans ◽  
Robert H. Stamps
Keyword(s):  
Physical Properties ◽  
Pore Space ◽  
Cocos Nucifera ◽  
Chemical Properties ◽  
Compression Pressure ◽  
Coconut Husk ◽  
Electrical Conductivities ◽  
Coir Dust ◽  
Processing Effects ◽  
Water Holding

Chemical properties of unprocessed coconut (Cocos nucifera L.) husks varied significantly among 11 sources tested. The pH and electrical conductivities were significantly different among husk sources and ranged from 5.9 to 6.9 and 1.2 to 2.8 mS·cm-1, respectively. The \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NH}_{4}^{+}\) \end{document}, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{NO}_{3}^{-}\) \end{document}, Ca, and Mg levels did not differ significantly among husk sources and ranged from 0.2 to 1.8, 0.2 to 0.9, 2.9 to 7.3, and nondetectable to 4.6 mg·kg-1, respectively. Levels of P, B, Cu, Fe, Ni, S, Zn, Mn, and Mo were all significantly different among husk sources and ranged from nondetectable levels to 33 ppm. The levels of Na, K, and Cl were significantly different among husk sources and ranged from 23 to 88, 126 to 236, and 304 to 704 ppm, respectively. Coir dust (CD) produced by screening of waste-grade coir through 3-, 6-, or 13-mm mesh screens had significantly different fiber content, bulk densities, total solids, total pore space, air-filled pore space, water-filled pore space, and water-holding capacities as compared with nonscreened waste-grade coir. However, screen size did not significantly affect the physical properties of CD. Neither compression pressure nor moisture level during compression of CD blocks significantly affected rehydration of compressed CD or physical properties of rehydrated CD.

scholarly journals Earthworm Castings as a Substrate Amendment for Chrysanthemum Production

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1035-1039 ◽  
Author(s):  
Pablo R. Hidalgo ◽  
Richard L. Harkess
Keyword(s):  
Bulk Density ◽  
Pore Space ◽  
Growth Index ◽  
Dry Weight ◽  
Water Holding Capacity ◽  
Dendranthema Grandiflora ◽  
Substrate Amendment ◽  
Sheep Manure ◽  
Air Space ◽  
Water Holding

Earthworm castings (vermicompost) were evaluated as a substrate amendment for chrysanthemum [Dendranthema ×grandiflora (Ramat.) Kitam.] `Miramar' production. Vermicompost produced from sheep, cattle, and horse manures were mixed at different ratios with 70 peatmoss: 30 perlite (v/v) to create 12 substrates. The 70 peatmoss: 30 perlite mix at 100% and Sunshine® Mix 1 were used as control substrates. The bulk density, percentage of pore space, and water holding capacity increased as vermicompost content increased while the percentage of air space decreased. At 100% vermicompost, water holding capacity and bulk density were greatest in vermicompost from sheep manure. Plants grown in mixtures of 50% vermicompost from sheep had a greater growth index at harvest, foliar area, number of flowers per pot, and dry weight and fewer days for flower development than plants grown in other substrates. Vermicompost from sheep manure added at 50% by volume was most effective as a substrate amendment for chrysanthemum production.

scholarly journals Effect of Soaking, Cooking, Germination and Fermentation Processing on Physical Properties and Sensory Evaluation of Sorghum Biscuits

2015 ◽  
Vol 7 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Abd El-Moneim M. R. AFIFY ◽  
Hossam Saad EL-BELTAGI ◽  
Samiha M. ABD EL-SALAM ◽  
Azza A. OMRAN
Keyword(s):  
Physical Properties ◽  
Sensory Evaluation ◽  
Kernel Weight ◽  
Physical Characteristics ◽  
Water Holding Capacity ◽  
Acceptable Quality ◽  
Water Holding

Three white sorghum varieties (named ‘Dorado’,‘Shandaweel-6’ and ‘Giza-15’) were investigated for grain characteristics and processed whole meal flour (via soaking, cooked, germinated and fermented sorghum). ‘Giza-15’ variety was the highest one in 1,000 kernel weight and hectolitre, followed by ‘Dorado’ and ‘Shandaweel-6’ that were significant lower. Sorghum varieties were non-significant different in L scales. ‘Giza-15’ was the highest variety in a and b scales. Sorghum varieties were significant different in c scales and non-significant different in h scales. Shandaweel-6 recorded the highest value in water holding capacity (WHC).‘Giza-15’recorded the highest variety in oil holding capacity (OHC). The most significant increase in WHO was after fermentation treatment, followed by cooking treatment. Regarding OHC, the most significant increase was after germination treatment. Biscuits prepared from 50% whole meal flour of raw, soaked, cooked, germinated and fermented sorghum were evaluated for sensory and physical characteristics. The sensory results showed that 50% sorghum whole meal flour could be incorporated to prepare acceptable quality biscuits. The diameter of sorghum biscuits increased, while the diameter of wheat biscuits decreased. Hardness of sorghum biscuits was significant decreased in all treatments compared with wheat biscuits. Hardness of germinated sorghum biscuits was close to wheat biscuits values.

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