Bulk density and relationship air/water of horticultural substrate

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.

Download Full-text

Effect of Different Extrusion Processing Parameters on Physical Properties of Soy White Flakes and High Protein Distillers Dried Grains-Based Extruded Aquafeeds

Journal of Food Research ◽

10.5539/jfr.v3n6p107 ◽

2014 ◽

Vol 3 (6) ◽

pp. 107 ◽

Cited By ~ 9

Author(s):

Sushil K. Singh ◽

K. Muthukumarappan

Keyword(s):

Physical Properties ◽

Water Absorption ◽

Bulk Density ◽

Water Solubility ◽

Expansion Ratio ◽

High Protein ◽

Regression Equations ◽

Process Variables ◽

Distillers Dried Grains ◽

Durability Index

Nutritionally balanced ingredient blends for catla (Catla catla), belonging to the family Cyprinidae, were extruded using single screw extruder. The extrusion was carried out at five levels of soy white flakes content (21%, 29%, 40%, 52%, and 59% db), five levels of moisture content (15, 19, 25, 31, and 35% db) and five levels of barrel temperature (100, 110, 125, 140, and 150 ºC) using three different die nozzles (having L/D ratios 3.33, 5.83, and 7.25). Blends with net protein content of 32.5% contains soy white flakes, along with high protein distillers dried grains (HP-DDG), corn flour, corn gluten meal, fish meal, vitamin, and mineral mix. A central composite rotatable design (CCRD) and response surface methodology (RSM) was used to investigate the significance of independent and interaction effects of the extrusion process variables on the extrudates physical properties namely pellet durability index, bulk density, water absorption and solubility indices and expansion ratio. Quadratic polynomial regression equations were developed to correlate the product responses and process variables as well as to obtain the response surfaces plots. The independent variables had significant (P < 0.05) effects on physical properties of extrudates: (i) higher soy white flakes content increased the pellet durability index and water absorption index, but decreased the water solubility index, (ii) higher temperature decreased pellet durability index, bulk density and water solubility index, (iii) increased L/D ratio from 3.33 to 7.25 increased the pellet durability index, expansion ratio but decreased the bulk density of the extrudates.

Download Full-text

Variations in selected soil physical properties with landforms and slope within an inland valley ecosystem in Ashanti region of Ghana

Soil and Water Research ◽

10.17221/17/2010-swr ◽

2011 ◽

Vol 6 (No. 2) ◽

pp. 73-82 ◽

Cited By ~ 6

Author(s):

S.E. Obalum ◽

J.C. Nwite ◽

J. Oppong ◽

C.A. Igwe ◽

T. Wakatsuki

Keyword(s):

Particle Size ◽

Moisture Content ◽

Particle Size Distribution ◽

Physical Properties ◽

Bulk Density ◽

Site Selection ◽

Total Porosity ◽

Soil Physical Properties ◽

Silt Fraction ◽

Inland Valley

One peculiar feature of the inland valleys abundant in West Africa is their site-specific hydrology, underlain mainly by the prevailing landforms and topography. Development and management of these land resources under the increasingly popular sawah (a system of bunded, puddled and levelled rice field with facilities for irrigation and drainage) technology is a promising opportunity for enhancing rice (Oryza sativa L.) production in the region. Information on the variations in selected soil physical properties as influenced by the prevailing landforms may serve as a useful guide in site selection. This is of practical importance since majority of the inland valleys are potentially unsuitable for sawah development and most farmers in the region are of low technical level. Three landforms (river levee, elevated area and depressed area) were identified within a sawah field located in an inland valley at Ahafo Ano South District of Ghana. Each of these landforms was topsoil-sampled along on identified gradient (top, mid and bottom slope positions). Parameters determined included particle size distribution, bulk density, total porosity and field moisture content. The soil is predominantly clayey. There were no variations in the particle size distribution among the slope positions in the river levee. Overall, the river levee had lower silt content than the elevated and the depressed landforms. The bulk density, total porosity, and gravimetric moisture content indicated relative improvements only in the depressed area in the order, bottom > mid > top slope. Irrespective of slope position, the three landforms differed in these parameters in the order, depressed > river levee > elevated. The sand fraction impacted negatively on the silt fraction and bulk density of the soil, both of which controlled the soil moisture status. Despite the fairly low silt content of the soil, the silt fraction strongly influenced the gravimetric moisture content (R2 = 0.80). So too did the soil bulk density on the gravimetric moisture content (R2 = 0.90). It is concluded that: (1) since the landforms more prominently influenced the measured parameters than the slope positions, the former should take pre-eminence over the latter in soil suitability judgment; (2) with respect to moisture retention, variations in silt fraction and bulk density of this and other clayey inland-valley soils should be used as guide in site selection for sawah development.

Download Full-text

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

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832008000400008 ◽

2008 ◽

Vol 32 (4) ◽

pp. 1437-1446 ◽

Cited By ~ 29

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.

Download Full-text

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

HortTechnology ◽

10.21273/horttech.18.3.384 ◽

2008 ◽

Vol 18 (3) ◽

pp. 384-388 ◽

Cited By ~ 10

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.

Download Full-text

Response of Cocoyam (Xanthosoma mafafa) Growth, Yield Parameters and Soil Physical Properties of Ultisol at Umudike, Southeastern Nigeria

Asian Soil Research Journal ◽

10.9734/asrj/2019/v2i430058 ◽

2020 ◽

pp. 1-10

Author(s):

Iroegbu, Chidinma S ◽

Asawalam, Damian O ◽

O. A. Dada ◽

J. E. Orji

Keyword(s):

Physical Properties ◽

Bulk Density ◽

Leaf Area ◽

Plant Height ◽

Poultry Manure ◽

Total Porosity ◽

Soil Bulk Density ◽

Soil Physical Properties ◽

Southeastern Nigeria ◽

Number Of Leaves

Aim: To determine the effect of different rates of sawdust (SD) and poultry manure (PM) applied on some soil physical properties of acid sandy Ultisol, and some growth parameters and yield of cocoyam. Study Design: 2 x 5 factorial arrangement in a randomized complete block design replicated three times. Place and Duration of Study: The experiment was conducted in Eastern farm of Michael Okpara University of Agriculture, Umudike during 2014 and 2015 planting seasons. Methodology: The treatments comprised of two manure sources at five levels each: sawdust (0, 2, 10, 15 and 20t/ha) and poultry manure (0, 2, 4, 6 and 8t/ha). The treatments were assigned randomly to the plots and incorporated into the soil two weeks before planting. Data were collected on plant height, number of leaves, leaf area, corms, cormels and total yield. Soil samples were collected with core samplers for physical properties such as Soil Bulk density and Total Porosity. All the data collected were subjected to ANOVA for factorial experiment in RCBD at 5% probability level. Results: The result showed that the interactions of poultry manure and sawdust significantly (p<0.05) improved soil bulk density and total porosity with the lowest value obtained with 0t/ha SD + 8t/ha PM in both 2014 and 2015. The result showed that the interactions of poultry manure and sawdust significantly (p<0.05) increased the leaf area with the highest value obtained with 20t/ha SD + 8t/ha PM in both 2014 and 2015. Also, only the increasing rates of treatment applied significantly (p<0.05) increased the number of leaves, plant height, leaf area and cocoyam yield with the highest value obtained with 20t/ha SD + 8t/ha PM. Also, the various rates of treatment application significantly (p<0.05) increased the cocoyam yield (weight of corms and cormels) with the highest value obtained with 20t/ha SD + 8t/ha PM. Conclusion: Improvement in growth and yield of cocoyam resulted from the improved nutrient status of the soil as a result of the amendments applied.

Download Full-text

Post-Harvest Evaluation of Soil Physical Properties and Natural Regeneration Growth in Steep-Slope Terrains

Forests ◽

10.3390/f10111034 ◽

2019 ◽

Vol 10 (11) ◽

pp. 1034 ◽

Cited By ~ 7

Author(s):

Hadi Sohrabi ◽

Meghdad Jourgholami ◽

Farzam Tavankar ◽

Rachele Venanzi ◽

Rodolfo Picchio

Keyword(s):

Physical Properties ◽

Bulk Density ◽

Natural Regeneration ◽

Recovery Period ◽

Total Porosity ◽

Penetration Resistance ◽

Soil Physical Properties ◽

Control Area ◽

Traffic Intensity ◽

Significant Difference

Protection of forest soils during harvesting operations is necessary to reduce damage and accelerate recovery time. The current study aims to evaluate soil physical properties, natural regeneration, and its recovery process in treatments including slope gradient, traffic intensity and skid trail after long periods of time, after ceasing the timber harvesting operations. The most recent skidding operations within each 5 years recovery period were studied for a chronosequence of 20 years. Soil samples were taken in abandoned skid trails and data were recorded on naturally regenerated species and density. The results revealed that most soil disturbances occurred on the slopes >20%, as well as the highest levels of traffic intensity. Bulk density and penetration resistance were still higher than the control area, with a significant difference between them, while total porosity was partially recovered. Twenty years after the skidding operation, soil bulk density and penetration resistance were 13.2% and 23.7% higher than the control area, while total porosity was 9.78% lower the than value of the control area. Seedlings of 50–150 cm and >150 cm in height on skid trails had significantly lower density than those in the control. The number of seedlings per m2 was less than the control area in all skid trails and for all height classes. The proportion of seedlings present in low traffic intensity was higher than in medium and high traffic intensities. The findings confirmed that full recovery rates are lengthy, and more time than 20 years is required to fully recover, especially with regards to penetration resistance.

Download Full-text

Influence of different tillage systems on soil physical properties and crop yield

Plant Soil and Environment ◽

10.17221/4236-pse ◽

2011 ◽

Vol 48 (No. 6) ◽

pp. 249-254 ◽

Cited By ~ 3

Author(s):

S. Husnjak ◽

D. Filipović ◽

S. Košutić

Keyword(s):

Winter Wheat ◽

Physical Properties ◽

Bulk Density ◽

Conservation Tillage ◽

Total Porosity ◽

Triticum Aestivum L ◽

Conventional Tillage ◽

Tillage Systems ◽

Ct System ◽

Air Capacity

An experiment with five different tillage systems and their influence on physical properties of a silty loam soil (Albic Luvisol) was carried in northwest Slavonia in the period of 1997–2000. The compared tillage systems were: 1. conventional tillage (CT), 2. reduced tillage (RT), 3. conservation tillage I (CP), 4. conservation tillage II (CM), 5. no-tillage system (NT). The crop rotation was soybean (Glycine max L.) – winter wheat (Triticum aestivum L.) – soybean – winter wheat. Differences between tillage systems in bulk density, total porosity, and water holding capacity and air capacity were not significant in winter wheat seasons. In soybean seasons, significant differences between some tillage systems were recorded in bulk density, total porosity, air capacity and soil moisture. The deterioration trend of physical properties was generally increasing in the order CM, CT, CP, NT and RT. The highest yield of soybean in the first experimental year was achieved under CT system and the lowest under CP system. In all other experimental years, the highest yield of winter wheat and soybean was achieved under CM system, while the lowest under RT system.

Download Full-text

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

HortScience ◽

10.21273/hortsci.44.3.874 ◽

2009 ◽

Vol 44 (3) ◽

pp. 874-878 ◽

Cited By ~ 4

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.

Download Full-text

KARAKTERISTIK SIFAT FISIK TANAH DAN C-ORGANIK PADA PENGGUNAAN LAHAN BERBEDA DI KAWASAN UB FOREST

Jurnal Tanah dan Sumberdaya Lahan ◽

10.21776/ub.jtsl.2021.008.2.11 ◽

2021 ◽

Vol 8 (2) ◽

pp. 395-405

Author(s):

Renaldy Christian Siahaan ◽

Zaenal Kusuma

Keyword(s):

Land Use ◽

Hydraulic Conductivity ◽

Physical Properties ◽

Bulk Density ◽

Particle Density ◽

Aggregate Stability ◽

Forest Area ◽

Land Uses ◽

Organic C ◽

Available Water

UB forest area has various land uses, namely the use of agroforestry land based on coffee and seasonal crops. This will result in various physical properties of the soil in each use, therefore this study aims to determine the physical properties of the soil in different land uses and obtain optimal land use in the UB Forest area. The research was conducted from June to September 2020 in Malang district. The study was conducted on land use of pine forest areas, pine agroforestry + coffee, pine agroforestry + seasonal crops, mahogany agroforestry + coffee and mahogany agroforestry + seasonal crops. The parameters observed included analyzing bulk density, particle density, porosity, available water, water content pF 2.5 and 4.2, hydraulic conductivity, aggregate stability, texture and organic-C. The results showed that land use in the forest area of UB affected the physical soil, namely bulk density, particle density, porosity, hydraulic conductivity, and aggregate stability. Other physical properties, namely soil texture in the UB area. Dominant forest with dusty and clayey clay textures while available water had no significant effect and pine land use is optimal use based on physical properties of soil density, density, aggregate stability and hydraulic conductivity and is supported by the value of organic-C. Soil organic matter in coffee pine land use also has the highest value than other land ranges from 3.44 to 5.07%

Download Full-text

Evaluation of the short-term effect of tillage practices on soil hydro-physical properties

Polish Journal of Soil Science ◽

10.17951/pjss.2019.52.1.43 ◽

2019 ◽

Vol 52 (1) ◽

pp. 43

Author(s):

Omid Bahmani

Keyword(s):

Physical Properties ◽

Water Retention ◽

Total Porosity ◽

Field Capacity ◽

Water Retention Capacity ◽

Model Parameters ◽

Retention Capacity ◽

Tillage Practices ◽

Available Water ◽

The Impact

Tillage is one of the most important practices that have a significant influence on the soil hydro-physical properties. In this study, the impact of the type and number of input variables with five different methods of the Retc model to predicting the moisture retention curve and soil water content in three surfaces tillage NT (No-tillage), CP (Chisel Plough) and MP (Moldboard Plough) and the impact of tillage systems on soil hydro-physical properties were evaluated. According to results, when the field capacity and wilting point moisture was added to input data in Retc to predict the moisture curve model parameters, the EF was increased in MP (0.977, 0.95) and CP (0.891, 0.86) treatments compare the NT (0.665, 0.608). The Mualem–Van Genuchten model can describe satisfactorily the simulation of soil physical properties. The S-index, which was also affected by tillage, was greater than 0.066 in all tillage treatments, indicating good soil physical quality. Results indicated that NT had the highest and lowest values of bulk density (1.55 Mgr.m-3) and total available water (TAW) (0.038 m.m-1), respectively, and the differences between NT and MP in total porosity was significant. Overall, in most soil layers, tillage practices affected the porosity and total available water in the order MP > CP > NT. Water retention curves indicated that the water retention capacity was greater in tilled than in no-tilled and saturated hydraulic conductivity values were greater in tilled treatments than in NT soil.

Download Full-text