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 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 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 Physical attributes of a Dystroferric Red Latosol (Oxisol) under different management systems

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Leandro Campos Pinto ◽  
Wantuir Filipe Teixeira Chagas ◽  
Francisco Hélcio Canuto Amaral
Keyword(s):  
Bulk Density ◽  
Soil Structure ◽  
Particle Density ◽  
Geometric Mean ◽  
Organic Matter Content ◽  
Total Porosity ◽  
Biological Properties ◽  
Matter Content ◽  
Native Vegetation ◽  
Red Latosol

The relationship of management and soil quality may be evaluated by the behavior of soil physical, chemical and biological properties. In the assessment of soil structure, it is sought attributes in the view of measuring the porosity and the distribution of pores by size and its implication to permeability and rigidity of the pores, as well as the stability of the units that composes soil structure. The aim of this research was to assess the structure of a Dystroferric Red Latosol (Oxisol) under conventional corn crop, conventional coffee crop, eucalyptus crop and an equilibrium reference (native vegetation), by the determination of the particle density, bulk density, calculated total porosity, microporosity, macroporosity, moisture saturation, determined total porosity, blocked pores and aggregated stability. Soil under native vegetation presented the lowest values of particle density, probably due to the greatest soil organic matter content in this environment. It was verified a tendency of increasing blocked pores and decreasing bulk density. As expected, bulk density varied from 0.87 to 1.03 g cm-3, showing an inversely proportional distribution related to total porosity. The largest values of geometric mean diameter presented by the soil under native vegetation are due to thegreater structuration degree of this soil, which contributes to the stabilization of the aggregates in this environment. The native vegetation environment presented a better soil physical quality in relation to other land uses.

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 Method to estimate soil macroporosity and microporosity based on sand content and bulk density

2011 ◽  
Vol 35 (2) ◽  
pp. 447-459 ◽  
Author(s):  
Rubismar Stolf ◽  
Álvaro de Mendonça Thurler ◽  
Osny Oliveira Santos Bacchi ◽  
Klaus Reichardt
Keyword(s):  
Bulk Density ◽  
Multiple Regression ◽  
Soil Compaction ◽  
Soil Degradation ◽  
Large Range ◽  
Total Porosity ◽  
Sand Content ◽  
Similar Accuracy ◽  
Root Aeration

Macroporosity is often used in the determination of soil compaction. Reduced macroporosity can lead to poor drainage, low root aeration and soil degradation. The aim of this study was to develop and test different models to estimate macro and microporosity efficiently, using multiple regression. Ten soils were selected within a large range of textures: sand (Sa) 0.07-0.84; silt 0.03-0.24; clay 0.13-0.78 kg kg-1 and subjected to three compaction levels (three bulk densities, BD). Two models with similar accuracy were selected, with a mean error of about 0.02 m³ m-3 (2 %). The model y = a + b.BD + c.Sa, named model 2, was selected for its simplicity to estimate Macro (Ma), Micro (Mi) or total porosity (TP): Ma = 0.693 - 0.465 BD + 0.212 Sa; Mi = 0.337 + 0.120 BD - 0.294 Sa; TP = 1.030 - 0.345 BD 0.082 Sa; porosity values were expressed in m³ m-3; BD in kg dm-3; and Sa in kg kg-1. The model was tested with 76 datum set of several other authors. An error of about 0.04 m³ m-3 (4 %) was observed. Simulations of variations in BD as a function of Sa are presented for Ma = 0 and Ma = 0.10 (10 %). The macroporosity equation was remodeled to obtain other compaction indexes: a) to simulate maximum bulk density (MBD) as a function of Sa (Equation 11), in agreement with literature data; b) to simulate relative bulk density (RBD) as a function of BD and Sa (Equation 13); c) another model to simulate RBD as a function of Ma and Sa (Equation 16), confirming the independence of this variable in relation to Sa for a fixed value of macroporosity and, also, proving the hypothesis of Hakansson & Lipiec that RBD = 0.87 corresponds approximately to 10 % macroporosity (Ma = 0.10 m³ m-3).

scholarly journals Evaluation of copper tailings from the abandoned Messina Mine for possible reuse in recreational projects, South Africa

2022 ◽  
Vol 9 (2) ◽  
pp. 3359-3366
Author(s):  
Sphiwe Emmanuel Mhlongo ◽  
Fulufhelo Lesego Makatu ◽  
Nhlanhla Khuzulwandle Malaza ◽  
Azwihangwisi Tendani Ramalata
Keyword(s):  
Bulk Density ◽  
Particle Density ◽  
Total Porosity ◽  
High Concentration ◽  
Quartz Content ◽  
Tailing Dump ◽  
Copper Tailings ◽  
Left Behind ◽  
Porosity And Permeability ◽  
Historic Mining

Historic mining of copper around Musina Town left behind a sizeable unrehabilitated tailing dump. This article reports on the study conducted to investigate the suitability of using copper tailings as sand replacement in recreational projects. The methodology used involved analyzing the particle size distribution and plasticity index (PI) of the tailings and determining their particle density, bulk density, particle shape, total porosity, and permeability coefficient. The pH of the tailings, major element oxides, and heavy metals composition were all analyzed. The tailings were classified as poorly graded sand with silt (SP-SM). Low fines (9.6%) and PI (1.4) values revealed that the copper tailings were texturally suitable for application in rootzones of sports fields, courts for beach volleyball, and bunkers of the golf courses. Their particle density (2.90 g/cm³), bulk density (1.53-1.89 g/cm³), porosity (34.62-47.04%), and permeability (1.42 x 10-3 cm/sec) were all within the recommended range for application in rootzones. The angular particles of the tailings supported their uses in the bunkers. However, their pH (7.9) and high quartz content (69% SiO2) confirmed their suitability for rootzones. However, the high concentration of Cu (1872.0 mg/kg) and Cr (159.5 mg/kg) was identified as a potential risk of using the copper tailings in rootzones. This and the relatively high Al2O3 (11%) and Fe2O3 (8%) suggested that the copper tailings should be first washed or processed before being used in any recreational projects. Developing a suitable technique for processing the studied copper tailings to enhance their properties for different recreational projects was recommended.

scholarly journals Comparison of the physical properties of soils belonging to different reference soil groups

2020 ◽  
Vol 16 (No. 1) ◽  
pp. 29-38
Author(s):  
Jan Vopravil ◽  
Pavel Formánek ◽  
Tomáš Khel
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Particle Density ◽  
Total Porosity ◽  
Capillary Water ◽  
Water Capacity ◽  
Available Water Capacity ◽  
Permanent Wilting Point ◽  
Wilting Point ◽  
Soil Groups

Soil properties can be influenced by long-term agricultural management practices as described in pedological literature. In this study, selected physical properties (particle density and bulk density, total porosity, maximum capillary water capacity, minimum air capacity, field capacity, permanent wilting point and available water capacity) of topsoils from different reference soil groups (Cambisols, Luvisols, Fluvisols, Chernozems and Phaeozems, Leptosols, Stagnosols and Gleysols) were sampled and analysed in the years 2016–2017. The topsoil samples were taken from points of so-called S (specific) soil pits to be sampled from the General Soil Survey of Agricultural Soils (GSSAS) which was accomplished in the years 1961–1970. In addition, some of the properties were also compared with those measured during the GSSAS. Recognising the properties, only the particle density, the maximum capillary water capacity, the permanent wilting point and the available water capacity of the topsoil of the individual soil groups were statistically significantly (P < 0.05) different. A comparison of the physical properties with those analysed after more than 40 years was performed, the bulk density increased and the total porosity decreased in the topsoil of the major part of the studied soil groups.

scholarly journals Calculating particle density, bulk density, and total porosity of soil based on its texture

2014 ◽  
Vol 65 (4) ◽  
pp. 139-149 ◽  
Author(s):  
ZYGMUNT BROGOWSKI ◽  
WOJCIECH KWASOWSKI ◽  
RENATA MADYNIAK
Keyword(s):  
Bulk Density ◽  
Physical State ◽  
Particle Density ◽  
Scientific Research ◽  
Total Porosity ◽  
General Description ◽  
Analytical Errors

Abstract This paper provides the verification of coefficients for the calculation of particle density, bulk density, and total porosity based on the texture of soils proposed by Brogowski (1990). The verified and supplemented coefficients for the calculation of particle density, bulk density, and total porosity permit obtaining credible results within the range of analytical errors. The proposed calculations of density and total porosity of soils can be used for the general description of soils. They cannot, however, replace exact scientific research on the physical state of soils.

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