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 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 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 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 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 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.

Growth of Container-grown Plants With and Without Azomite Soil Amendment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 492c-492
Author(s):  
Chris Ely ◽  
Mark A. Hubbard
Keyword(s):  
Plant Growth ◽  
Physical Properties ◽  
Bulk Density ◽  
Soil Amendment ◽  
Extended Period ◽  
Mineral Elements ◽  
Field Soil ◽  
Rooted Cuttings ◽  
Sodium Calcium ◽  
Water Holding

Azomite is a mined, commercially available, hydrated sodium calcium aluminosiliclate soil amendment reported to act as a source of mineral elements. To determine its effect on plant growth, Dendranthema `Connie' rooted cuttings, Malus seedlings, and Citrus seedlings were grown in containers in one of two growing media: ProMix BX or ProMix BX with Azomite (1:1, v:v). Plant height was monitored weekly and after 6 weeks of growth, fresh and dry plant weights of roots and shoots were determined. There was no difference in any of the parameters measured as a result of the addition of Azomite. Any nutritional influence of the Azomite may only be evident in different conditions, e.g., field soil, or over an extended period of time. The Azomite altered the medium's physical properties and therefore bulk density and water-holding capacity of the Azomite were determined for consideration.

scholarly journals GROWTH OF BEDDING PLANTS IN MINERAL WOOL AND MINERAL WOOL/PEAT MIXES

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 686b-686 ◽  
Author(s):  
Thomas M. Contrisciano ◽  
E. Jay Holcomb
Keyword(s):  
Plant Growth ◽  
Bulk Density ◽  
Dry Weight ◽  
Optimal Level ◽  
Mineral Wool ◽  
Water Holding Capacity ◽  
Peat Moss ◽  
High Ph ◽  
Bedding Plants ◽  
Water Holding

The objective of this research was to develop a mineral wool based growing medium for the horticultural industry. Two types of hydrophilic mineral wool, clean wool (CW) and unclean wool (UC) were used unamended, as well as both types in combinations with 25, 50, and 75 percent peat moss (PM). A control of 100 percent (PM) was also used. Unamended CW had a low bulk density, excellent water holding capacity, good aeration, but high pH. Once PM was added to CW, bulk density still remained low, water holding capacity and aeration remained good, and the pH dropped to a more suitable level. Unamended UW had a high bulk density, good water holding capacity, poor aeration, and high pH. Once PM was added to UW, bulk density decreased, water holding capacity remained good, aeration increased, and pH decreased to a more optimal level. Impatiens `Violet' and Begonia `Whiskey' were grown in the nine treatments for six and nine weeks respectively. At harvest, plant growth was evaluated by height, diameter, fresh weight, dry weight, and tissue analysis. Plant growth response showed plants grown in unamended CW, UW, and PM were smaller in size and lighter in fresh and dry weights than those in 50 percent wool/50 percent PM. The plants grown in 25 and 75 percent PM were similar to the 50 percent wool/50 percent PM in size and weight.

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 Characterization of Biochars From Tropical Biomass

Khazanah ◽  
2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Warit Abi Nurazaq ◽  
◽  
Bambang Purwantana ◽  
Radi Radi ◽  
Andri Prima Nugroho ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Physical Properties ◽  
Bulk Density ◽  
Rice Straw ◽  
Rice Husk ◽  
Soil Amendment ◽  
Water Holding Capacity ◽  
Agricultural Residue ◽  
Pyrolysis Method ◽  
Water Holding

Tropical country has a large biomass provide from agricultural residue. The biomass has potential to be processed as biochar. In general, biochar can be utilized as soil amendment in order to increase the ability of soil to retain nutrients, reduce surface runoff, due to excess water, and adding biodiversity of soils that are very useful for plant growth. The biochar characteristics are strongly related to the feedstock types and also their pyrolysis method. This research aims to study the physical characteristics of tropical biochar and their potential suitability in soil improvement. The biochar was produced by slow pyrolysis method using a vertical bed kiln. The feedstock were 9 types of agricultural residue including: mango leaf, longan leaf, teak leaf, mango branch, longan branch, rubber branch, corncob, rice straw, and rice husk. Temperature of the pyrolisis process was in the range of 400 °C to 600 °C. The results indicated that the physical properties of feedstock affects the characteristics of biochar. The higher bulk density and fixed carbon value the greater yield of biochar. Compare to their raw materials, the average water content of biochar was reduced (0.2–3.85 %), while pH increased (7.06–9.9). The electrical conductivity in general also increased (0.11–2.9 ds.m-1 ). Bulk density changed, corncob, and branches materials decreased, while rice straw, rice husk and leaves materials increased. The water holding capacity was a fairly low number (4–20 %). Application of the utilized biochar as a soil amendment is to improve soil chemical properties (pH, electrical conductivity, and availability of N-P contents) and physical properties (bulk density, porosity, and water holding capacity). Application for different soil types requires different biochar characteristics, it is influenced by the type of raw material used, temperature, and combustion time.

Sign in / Sign up

Export Citation Format

Share Document