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.

scholarly journals Short and long-term effects of tillage systems and nutrient sources on soil physical properties of a Southern Brazilian Hapludox

2008 ◽  
Vol 32 (4) ◽  
pp. 1437-1446 ◽  
Author(s):  
Milton da Veiga ◽  
Dalvan José Reinert ◽  
José Miguel Reichert ◽  
Douglas Rodrigo Kaiser
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Crop Residues ◽  
Total Porosity ◽  
Soil Physical Properties ◽  
Soil Tillage ◽  
Tillage Systems ◽  
Nutrient Sources ◽  
Over Time

Soil tillage promotes changes in soil structure. The magnitude of the changes varies with the nature of the soil, tillage system and soil water content and decreases over time after tillage. The objective of this study was to evaluate short-term (one year period) and long-term (nine year period) effects of soil tillage and nutrient sources on some physical properties of a very clayey Hapludox. Five tillage systems were evaluated: no-till (NT), chisel plow + one secondary disking (CP), primary + two (secondary) diskings (CT), CT with burning of crop residues (CTb), and CT with removal of crop residues from the field (CTr), in combination with five nutrient sources: control without nutrient application (C); mineral fertilizers, according to technical recommendations for each crop (MF); 5 Mg ha-1 yr-1 of poultry litter (wetmatter) (PL); 60 m³ ha-1 yr-1 of cattle slurry (CS) and; 40 m³ ha-1 yr-1 of swine slurry (SS). Bulk density (BD), total porosity (TP), and parameters related to the water retention curve (macroporosity, mesoporosity and microporosity) were determined after nine years and at five sampling dates during the tenth year of the experiment. Soil physical properties were tillage and time-dependent. Tilled treatments increased total porosity and macroporosity, and reduced bulk density in the surface layer (0.00-0.05 m), but this effect decreased over time after tillage operations due to natural soil reconsolidation, since no external stress was applied in this period. Changes in pore size distribution were more pronounced in larger and medium pore diameter classes. The bulk density was greatest in intermediate layers in all tillage treatments (0.05-0.10 and 0.12-0.17 m) and decreased down to the deepest layer (0.27-0.32 m), indicating a more compacted layer around 0.05-0.20 m. Nutrient sources did not significantly affect soil physical and hydraulic properties studied.

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 Influence of Pumice and Plant Roots on Substrate Physical Properties Over Time

2011 ◽  
Vol 21 (5) ◽  
pp. 554-557 ◽  
Author(s):  
James E. Altland ◽  
James S. Owen ◽  
Magdalena Z. Gabriel
Keyword(s):  
Physical Properties ◽  
Pseudotsuga Menziesii ◽  
Total Porosity ◽  
Plant Roots ◽  
Production Environment ◽  
The Core ◽  
Air Space ◽  
Treatment Design ◽  
Substrate Types ◽  
Over Time

An experiment was conducted to test the hypothesis that either pumice or plant roots maintain air space (AS) and porosity over time, or renders substrates more resistant to shrinkage. Treatment design was a 3 × 2 factorial with three substrate types and either presence or absence of a plant. The three substrates were composed of douglas fir (Pseudotsuga menziesii) bark alone or amended with 15% or 30% (by volume) pumice. Substrates were packed in aluminum cores to facilitate measurement of physical properties with porometers at the conclusion of the experiment. Half of the cores with each of the three substrate types were packed with a single plug of ‘Autumn Blush’ coreopsis (Coreopsis sp.) (Expt. 1) or ‘Blue Prince’ holly (Ilex ×meserveae) (Expt. 2). The remaining cores were maintained in the same production environment, but without a plant. Substrate physical properties were measured before the experiment and after 48 days for coreopsis plants and 382 days for holly. Both experiments had relatively similar responses despite using different crops and production times. Summarizing in general overall treatments, AS decreased, container capacity (CC) and total porosity (TP) increased, and bulk density remained constant over time. The presence of a plant in the core tended to exacerbate the decrease in AS and the increase in core capacity. Shrinkage was decreased by the presence of a plant, but only minimally.

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 Composted Yard Waste as a Component of Container Substrates

1996 ◽  
Vol 14 (3) ◽  
pp. 115-121 ◽  
Author(s):  
R.C. Beeson
Keyword(s):  
Root Growth ◽  
Physical Properties ◽  
Shoot Growth ◽  
Total Porosity ◽  
Coarse Sand ◽  
Pine Bark ◽  
Growth Substrate ◽  
Yard Waste ◽  
Pittosporum Tobira ◽  
Better Than

Abstract Rhododendron indicum (L.) Sweet ‘Due du Rohan’ and Pittosporum tobira variegata Ait. were produced in 10.2 liter (#3) containers in substrates consisting of 20, 40, 60, and 80% (v/v) composted yard waste mixed with pine bark and coarse sand. Plant growth, substrate physical properties, and N and P leachate were compared with a control substrate of pine bark fines:sledge peat:sand (3:1:1 by vol). Shoot growth of plants in compost substrates was similar or better than control plants and greater with daily irrigation compared to alternate day irrigation. Root growth and percent air porosity declined as compost composition and waterholding capacity increased. Total porosity was generally consistent throughout the study. Irrigation regime had no effect on root growth nor substrate physical properties. Ammonium, NO3-N, and P concentrations in leachates varied with substrate and time following topdressing with controlled release fertilizer. Both species grew best in the 40% compost, 50% pine bark, and 10% sand substrate.

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.

scholarly journals Impact of Hydrogel on Physical Properties of Coarse-structured Horticultural Substrates

1993 ◽  
Vol 118 (2) ◽  
pp. 217-222 ◽  
Author(s):  
W.C. Fonteno ◽  
T.E. Bilderback
Keyword(s):  
Hydraulic Conductivity ◽  
Physical Properties ◽  
Direct Contact ◽  
Total Porosity ◽  
Dry Weight ◽  
Pine Bark ◽  
Distilled Water ◽  
Polyacrylamide Hydrogel ◽  
Pressure Plate ◽  
Air Space

Addition of a polyacrylamide hydrogel to pine bark and pine bark + sand substrates had no effect on total porosity, regardless of incorporation rate. Container capacity was increased with increasing rate of hydrogel in both substrates. Air space in pine bark was slightly increased at the lowest rate but was reduced with higher incorporation rates. Air space in pine bark + sand was reduced with all hydrogel additions. The dry weigh', of hydrogel cubes recovered from both substrates was similar to amounts predicted. This result indicates that blending hydrogel granules into the substrates was uniform and did not contribute to variability in hydrogel studies. After allowing dry hydrogel granules to expand freely in distilled water for 24 hours, hydrogel granules expanded 317 and 372 times their dry weights at the lowest and highest rates, respectively. Reduction of expansion (in water) at higher rates may have been due to physical restriction of expansion. Conversely, recovered hydrogel cubes from substrates watered to drainage (-10% excess) for 6 weeks absorbed 25 to 55 times their dry weight while in the container. Subsequent rehydration of extracted gels in distilled water was greater for hydrogel cubes from the pine bark + sand medium (104 to 130) than in pine bark alone (51 to 88). Because of anomalies in hydraulic conductivity and pressure plate contact, three techniques were used to study unavailable water content in gels expanded in distilled water. Hydrogel cubes placed in direct contact with the pressure plate released ≈95% of their water at pressures ≤ 1.5 MPa. Effectiveness of ployacrylamide gels in coarse-structured substrates is influenced by physical restrictions to expansion in the substrate and hydraulic conductivity between the hydrogel cubes and the surrounding substrate.

scholarly journals Rhizometer: An Apparatus to Observe and Measure Root Growth and Its Effect on Container Substrate Physical Properties Over Time

HortScience ◽  
2015 ◽  
Vol 50 (2) ◽  
pp. 288-294 ◽  
Author(s):  
Lesley A. Judd ◽  
Brian E. Jackson ◽  
William C. Fonteno
Keyword(s):  
Root Growth ◽  
Physical Properties ◽  
Root System ◽  
Root Length ◽  
Crop Production ◽  
Root Systems ◽  
Easy Access ◽  
Total Root Length ◽  
Change Over Time ◽  
Over Time

Container production of plants use substrates that are formulated to have adequate physical properties to sustain optimal plant growth; however, these properties can change over time as a result of substrate settling and root growth of the growing plant in the container. An apparatus (rhizometer) was developed that measures the changes caused by plant roots on physical properties of substrates during crop production in containers. The design of the rhizometer included a clear core, which allowed for observing and measuring a range of root system characteristics in situ, including total root length visible along the rhizometer. Physical properties of planted and fallow rhizometers were measured, and the effect of four species on substrate physical properties was determined. There was a general decrease in substrate total porosity and air space (AS) over time with both fallow and planted rhizometers as a result of both settling of the substrate and root growth into the substrate. Container capacity did not change over time with or without roots. Plants with large root systems such as Begonia ×hybrida acut. decreased AS over time, whereas plants of Rudbeckia hirta L. with a smaller root system did not have the same effect. Measured total root length was highly correlated to the total dry root mass of Tagetes erecta L. and Zinnia marylandica D.M. Spooner, Stimart & T. Boyle plants. This may allow tracing and measuring root lengths to be another (alternative) method to measure root systems. Planted rhizometers also allowed easy access for viewing the root system non-destructively, providing the ability to observe and measure root growth.

Sign in / Sign up

Export Citation Format

Share Document