scholarly journals Effect of the skid trail cross section and horizontal alignment on forest soil physical properties

2017 ◽  
Vol 63 (No. 4) ◽  
pp. 161-166
Author(s):  
Yazarlou Hossein ◽  
Parsakhoo Aidin ◽  
Habashi Hashem ◽  
Soltauninejad Soltan Ali
Keyword(s):  
Bulk Density ◽  
Forest Soil ◽  
Cross Section ◽  
Soil Bulk Density ◽  
Middle Part ◽  
Soil Porosity ◽  
Vertical Alignment ◽  
Horizontal Alignment ◽  
Significant Difference ◽  
The Cross

Horizontal alignment and cross section characteristics of a skid trail in a ground-based skidding system including curves, wheel ruts and cross slope can impact on the forest soil. In this study the measurement of cross section and vertical alignment of skid trail in Bahramnia forestry plan was done using a levelling instrument. Horizontal alignment of skid trail including straight routes and curves was taken using polar methods. A 3D map of skid trail was produced in AutoCAD Civil3D software. Soil bulk density was measured after sampling the soil with a core sampler. Results showed that in straight routes, soil bulk density increased by increasing the cross slope of skid trail. Moreover, soil porosity decreased with the increasing cross slope. There was a significant difference between cross slopes in soil moisture. On curves, maximum bulk density occurred when the cross slope was 10%. Findings about soil porosity and moisture on curves of skid trails were similar to those of straight routes. Based on our findings, soil bulk density in wheel ruts was significantly lower than that in the middle part of skid trail. Soil bulk density in the silty soil texture of studied skid trails was a little more than ideal bulk density, so it cannot affect and restrict root growth.

scholarly journals Soil Bulk Density and Porosity Changes due to Ground-based Timber Extraction in the Hyrcanian Forest

2013 ◽  
Vol 5 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Shoukuh SOLTANPOUR ◽  
Meghdad JOURGHOLAMI
Keyword(s):  
Bulk Density ◽  
Forest Soil ◽  
Soil Bulk Density ◽  
Forest Harvesting ◽  
Control Area ◽  
Soil Porosity ◽  
Percentage Increase ◽  
Hyrcanian Forest ◽  
Low Intensity ◽  
Porosity Reduction

Assessment and management of environmental impacts of forest harvesting activities, one of the main reasons is that its importance is increasing day by day. Skidding operations could lead to an increase in detrimental soil disturbance and soil surface compaction that reduced forest soil fertilities. The aim of this study was to investigate and quantify of forest soil compaction following the skidding operations with wheeled cable skidder. This study was carried out in compartment no. 311 and 319 in Gorazbon district in Kheyrud forest in Hyrcanian forest. This study was conducted in a completely randomized factorial design and changes in soil bulk density and porosity with the skidder traffic intensity such as low intensity (less than 3 passes), moderate (3 to 7 passes) and very large (more than 7 passes) and two depths of 0-10 and 10-20 cm of soil were measured. The results showed that with the increase of machine traffic, soil bulk density was increased but the largest percentage increase was observed in initial passes (less than 3 times). Soil bulk density at the depth 0-10 and 10-20 cm, was more than the control area by 21.2 and 6.5 percent, respectively. Soil porosity percentage at wheel rut was decreased comparing to the control area and this reduction in the 0-10 cm depth was greater than 10-20 cm soil depth. The most of the porosity reduction were occurred in the low intensity traffic and increase in skidder traffic has shown less effect on reducing soil porosity.

scholarly journals Tillage and crop rotation effects on soil carbon and selected soil physical properties in a Haplic Cambisol in Eastern Cape, South Africa

2019 ◽  
Vol 15 (No. 1) ◽  
pp. 47-54 ◽  
Author(s):  
Mxolisi Mtyobile ◽  
Lindah Muzangwa ◽  
Pearson Nyari Stephano Mnkeni
Keyword(s):  
South Africa ◽  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Crop Rotation ◽  
Soil Bulk Density ◽  
Crop Rotations ◽  
Soil Porosity ◽  
No Till

The effects of tillage and crop rotation on the soil carbon, the soil bulk density, the porosity and the soil water content were evaluated during the 6<sup>th</sup> season of an on-going field trial at the University of Fort Hare Farm (UFH), South Africa. Two tillage systems; conventional tillage (CT) and no-till and crop rotations; maize (Zea mays L.)-fallow-maize (MFM), maize-fallow-soybean (Glycine max L.) (MFS); maize-wheat (Triticum aestivum L.)-maize (MWM) and  maize-wheat-soybean (MWS) were evaluated. The field experiment was a 2 × 4 factorial, laid out in a randomised complete design. The crop residues were retained for the no-till plots and incorporated for the CT plots, after each cropping season. No significant effects (P &gt; 0.05) of the tillage and crop rotation on the bulk density were observed. However, the values ranged from 1.32 to1.37 g/cm<sup>3</sup>. Significant interaction effects of the tillage and crop rotation were observed on the soil porosity (P &lt; 0.01) and the soil water content (P &lt; 0.05). The porosity for the MFM and the MWS, was higher under the CT whereas for the MWM and the MWS, it was higher under the no-till. However, the greatest porosity was under the MWS. Whilst the no-till significantly increased (P &lt; 0.05) the soil water content compared to the CT; the greatest soil water content was observed when the no-till was combined with the MWM rotations. The soil organic carbon (SOC) was increased more (P &lt; 0.05) by the no-till than the CT, and the MFM consistently had the least SOC compared with the rest of the crop rotations, at all the sampling depths (0–5, 5–10 and 10–20 cm). The soil bulk density negatively correlated with the soil porosity and the soil water content, whereas the porosity positively correlated with the soil water content. The study concluded that the crop rotations, the MWM and the MWS under the no-till coupled with the residue retention improved the soil porosity and the soil water content levels the most.

Some Remarks on the Density of Interplanetary Dust Grains

1985 ◽  
Vol 85 ◽  
pp. 137-140
Author(s):  
P.L. Lamy
Keyword(s):  
Kinetic Energy ◽  
Bulk Density ◽  
Cross Section ◽  
Optical Sensors ◽  
Interplanetary Dust ◽  
Relevant Parameter ◽  
Dust Grains ◽  
Gravitational Forces ◽  
The Cross

AbstractThe relevance of the bulk density as a physical parameter characterizing interplanetary dust grains is discussed. The various measurements which lead to a determination of this parameter are reviewed. The specific case of the collected interplanetary dust grains is considered.The bulk density of interplanetary dust grains has been and is still a matter of controversy. This quantity cannot, in general, be directly measured; it is used to relate the mass and the size of a grain. This duality stems from physics itself as there are interactions sensitive to the mass (e.g., gravitational forces) while others are sensitive to the size or the cross-section (e.g., light scattering, radiation pressure, gas and plasma interactions). The measuring technics of the grains reflect this duality as, for instance, impact sensors are generally sensitive to the kinetic energy and thus to the mass, while optical sensors are sensitive to the cross-section. One sees that the density is not strictly speaking the relevant parameter, but what is needed is a relationship between mass and average cross-section.

Formation of ssb, dsb, and Uracil in Monofilarly and Bifilarly Bromouracil-Substituted DNA Molecules

1992 ◽  
Vol 47 (3-4) ◽  
pp. 255-263
Author(s):  
Henning Menke ◽  
Wolfgang Köhnlein
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Uv Light ◽  
Linear Part ◽  
Reversed Phase ◽  
Direct Production ◽  
Significant Difference ◽  
Effect Curve ◽  
The Cross

Abstract Bifilarly BU-substituted ColE 1 plasmid and monofilarly BU-substituted M 13 phage DNA were irradiated with UV light of 313 nm. Using agarose gel electrophoresis and “reversed phase” HPLC technique ssb, dsb induction and uracil formation, respectively, could be detected in the irradiated DNA in dependence on the UV fluence. The analysis of the strandbreaks in bifilar Col E1 DNA shows a significant part of directly induced dsb. Cross sections of ssb induction from 4.1 m2/J x 107 in 28%, 3.9 m2/J x 107 in 55% and 3.1 m2/J x 107 in 8 5 -9 0% BU-substituted DNA were calculated. The cross section for dsb induction was found to be 0.04 m2/J x 107, estimated from the linear part of the fluence effect curve. In monofilar M13 DNA a linear fluence effect curve for dsb induction was obtained. Excluding other than the direct production of dsb by using an in vitro approach for M13 DNA , the results strongly support the hypothesis that dsb can be induced by one photochem ical absorption event. The cross section for ssb was 3.8 m2/J x 107 and for dsb 0.05 m2/J x 107 in 41.5% monofilarly BU-substituted M13 DNA . The comparison of ssb, dsb, and uracil production in bifilar and monofilar DNA with similar BU substitution showed no significant difference between the two DNA systems (ColE 1, M 13), indicating that the location of BU molecules in one or in both DNA strands will not lead to a different number of lesions after UV313 exposure.

Estimating forest soil bulk density using boosted regression modelling

2010 ◽  
Vol 26 (4) ◽  
pp. 516-528 ◽  
Author(s):  
S. S. M. Jalabert ◽  
M. P. Martin ◽  
J.-P. Renaud ◽  
L. Boulonne ◽  
C. Jolivet ◽  
...  
Keyword(s):  
Bulk Density ◽  
Forest Soil ◽  
Soil Bulk Density ◽  
Regression Modelling

scholarly journals Bulk density and porosity of soils influenced by skidding operations in the Nkrankwanta Off-Forest Reserve of Ghana

2021 ◽  
Vol 8 (2) ◽  
pp. 1409-1415
Author(s):  
Ammal Abukari ◽  
Donkor Christian ◽  
Kwame Ochire-Boadu
Keyword(s):  
Physical Properties ◽  
Bulk Density ◽  
Block Design ◽  
Soil Surface ◽  
Soil Bulk Density ◽  
Soil Physical Properties ◽  
Soil Porosity ◽  
Forest Reserve ◽  
Randomized Block Design ◽  
Increasing Trends

 Heavy forest machinery used in skidding has the capacity to influence the physical properties of soils. These may possibly lead to an upsurge in soil disruption and compaction of the soil surface decreases forest soil fertilities. This study assesses the effects of skidding on some soil physical properties such as the soil bulk density and porosity in the Nkrankwanta off-forest reserve in Ghana. The treatments comprised of four traffic intensity levels (1, 5, 10, and 15 passes) of the Mercedes Benz skidder (MB) Trac 1800 and a slope of two levels (less than 20 % and greater than 20 %) in a completely randomized block design. In addition, porosity and soil bulk density were assessed at varied distances from the MB Trac 1800. Soil bulk density results showed increasing trends with traffic frequency. Soil bulk density measured in the undisturbed area was 0.64 g cm-3 and 0.56 g cm-3 at slopes of less than 20% and greater than 20%, respectively. On the skid trail, soil bulk density significantly increased with traffic frequency (p<0.05). However soil porosity declined. Soil porosity estimated in uninterrupted area was 59.10 % and 57.40 % at < 20% and > 20% slope, respectively. Soil porosity was significantly influenced via different skidder passes (p<0.05). The soil physical properties were not influenced by the steepness of the slope however acted together in the number of passes to influence soil porosity. The impacts of the skidder on soil physical properties were significantly apparent at distances of 2 m to each sideway of the skidding trail. In conclusion, distinct responsiveness ought to be considered throughout the operations of skidding to curtail unfriendly influences on soil physical properties in ground-base skidding.

scholarly journals Silage-corn harvesting machinery traffic effects on soil bulk density and water permeability

2013 ◽  
Vol 59 (No. 4) ◽  
pp. 136-140
Author(s):  
I. Ahmadi ◽  
H. Ghaur
Keyword(s):  
Bulk Density ◽  
Water Permeability ◽  
Soil Compaction ◽  
Field Experiments ◽  
Soil Bulk Density ◽  
Soil Sampling ◽  
Soil Porosity ◽  
Silty Clay ◽  
Water Permeability Coefficient ◽  
Loam Soil

Soil compaction caused by machinery traffic affects the growth of agricultural crops and also has environmental effects like soil damage and erosion. Field experiments were conducted to study the effects of repeated silage-corn harvesting machinery traffic on dry soil bulk density and porosity variations at three different sampling depths, moreover average water permeability coefficient of the examined silty clay loam soil was measured using the falling head method of water permeability test. The examined treatments which were applied while harvesting silage-corn with the combination of tractor, chopper and truck were the number of traffic passes and depths of soil sampling. Significant differences between soil compaction treatments were observed in bulk density and porosity of soil. Numerically, 22% increase in soil bulk density and 19% reduction in soil porosity were recorded due to the effect of two passes of the examined machineries over the field terrain comparing to the non-traffic treatment. Moreover; soil sampling at 0&ndash;10 cm and 20&ndash;30 cm depths resulted in the highest and the lowest soil porosity respectively.

Does Sampler Size Affect Southeastern Piedmont Forest Soil Bulk Density Estimation?

2018 ◽  
Vol 49 (6) ◽  
pp. 701-707
Author(s):  
T. Adam Coates ◽  
Thomas A. Waldrop ◽  
Victor B. Shelburne ◽  
Hoke S. Hill
Keyword(s):  
Bulk Density ◽  
Forest Soil ◽  
Density Estimation ◽  
Soil Bulk Density

scholarly journals Soil properties and crop yield under different tillage methods for rapeseed cultivation in paddy fields

2015 ◽  
Vol 60 (1) ◽  
pp. 11-22
Author(s):  
Mohammad Alizadeh ◽  
Alireza Allameh
Keyword(s):  
Seed Germination ◽  
Grain Yield ◽  
Bulk Density ◽  
Crop Yield ◽  
Block Design ◽  
Soil Bulk Density ◽  
Dry Mass ◽  
No Till ◽  
Significant Difference ◽  
Tillage Methods

A two-year research was conducted to investigate the effect of different tillage methods on some soil physical characteristics and crop yield in rapeseed cultivation after rice harvesting. Five tillage treatments including: (i) using rotavator, once to depth of 10-15 cm (T1), (ii) using rotavator, twice to depth of 10-15 cm (T2), (iii) using moldboard plow to depth of 25 cm + rotavator, once to depth of 10-15 cm (T3), (iv) no-till planting through removing rice stubbles from plots (T4), and (v) no-till planting without removing rice stubbles from plots (T5), were evaluated under randomized complete block design (RCBD) in three replications. The biannual results revealed that the effect of tillage methods was significant (p<0.01) on soil bulk density, surface residues after tillage, dry mass of weeds, seed germination, and grain yield. T2 and T3 made considerable reduction in soil bulk density compared to other treatments for the 15- to 30-cm tillage depths. In T1, T2, T3, and T4, surface residues after tillage decreased in comparison with T5 by up to 35.37, 50.71, 69.92, and 75.75%, respectively. Having 71.48 g m-2, T5 had the maximum dry mass of weeds while T3 had the minimum one with 37.50 g m-2. Means comparison represented that in T2 and T3, seed germination reached the shortest length of 6.4 days in average. The highest and lowest grain yields were acquired in T3 (1,571 kg ha-1) and T5 (1,339 kg ha-1), respectively. Statistically, there was no significant difference between T1 (1,432 kg ha-1) and T2 (1,537 kg ha-1) compared with T3 in terms of grain yield.

scholarly journals Moisture distribution over tree trunk cross-section in bilberry spruce forests

2021 ◽  
Vol 25 (2) ◽  
pp. 35-40
Author(s):  
P.A. Feklistov ◽  
◽  
A.V. Gryazkin ◽  
I.N. Bolotov ◽  
O.N. Tyukavina ◽  
...  
Keyword(s):  
Moisture Content ◽  
Water Supply ◽  
Cross Section ◽  
Wood Moisture Content ◽  
Moisture Distribution ◽  
Age Classes ◽  
Wood Moisture ◽  
Spruce Forests ◽  
Significant Difference ◽  
The Cross

The article considers the change in the moisture content in the wood along the cross-section of spruce trunks, it also analyzes the influence of the trees age and the diameter of the trunk on the wood moisture content. The research was carried out in the Arkhangelsk Forestry in the bilberry spruce forests of different age classes (from IV to VIII). 10 trial plots were laid in clear stands or with a small mixture of birch and pine. To study the moisture content of spruce trunks, 15 sample trees (150 in total) were selected for each trial plot. The wood moisture content was determined on cores sequentially divided into 5-millimeter segments. Wood samples were weighed on a VT-500 torsion balance and dried in a drying cabinet at a temperature of 105 °C to a completely dry state. The relative moisture of wood was calculated. As a result of the conducted studies, the moisture of sapwood (from 44,8 to 45,9 %) and heartwood (from 32,2 to 36,1 %) was established. Two models of changes in the amount of water at different distances from the cambium were identified. The majority of trees (78–98 %) are characterized by a well-defined water supply zone, the moisture content of which is maximum at a distance of up to 25 mm from the cambium, after which it decreases sharply. The water supply zone is represented by approximately 40...50 outer annual rings. The second model is characterized by a gradual decrease in wood moisture along the radius from the periphery to the center of the trunk. Such a model of changes in the moisture content of wood in the cross-section of the trunk is rare, mainly in young trees. As the trunk diameter increases, the moisture content of sapwood decreases. There was no significant difference in the sapwood moisture of spruce trunks of different age classes. The sapwood moisture decreases from the root neck to 1.5 m in height of the trunk, varying from 52...53 % to 49,0...49,5 %.

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