Soil compaction and cotton growth on a vertisol

Soil Research ◽  
1990 ◽  
Vol 28 (6) ◽  
pp. 869 ◽  
Author(s):  
D Mcgarry
Keyword(s):  
Pore Volume ◽  
Soil Profile ◽  
Soil Compaction ◽  
Soil Structure ◽  
Growth Yield ◽  
Root Systems ◽  
Cotton Crop ◽  
Specific Pore Volume ◽  
Structure Degradation ◽  
Seedbed Preparation

Differences in growth, yield and root systems of two adjoining cotton crops on a Vertisol near Dalby, Queensland, were explained in terms of soil profile morphology and soil shrinkage indices. The soil beneath the strongly inferior crop had platy structure in the 0.05-0.28 m layer and significantly less air-filled specific pore volume in the 0.2-0.4 m layer. This soil structure degradation was caused by seedbed preparation of wet soil, prior to sowing the cotton crop.

Corrigenda - Soil compaction and cotton growth on a vertisol

Soil Research ◽  
1990 ◽  
Vol 28 (6) ◽  
pp. 869
Author(s):  
D Mcgarry
Keyword(s):  
Pore Volume ◽  
Soil Profile ◽  
Soil Compaction ◽  
Soil Structure ◽  
Growth Yield ◽  
Root Systems ◽  
Cotton Crop ◽  
Specific Pore Volume ◽  
Structure Degradation ◽  
Seedbed Preparation

Differences in growth, yield and root systems of two adjoining cotton crops on a Vertisol near Dalby, Queensland, were explained in terms of soil profile morphology and soil shrinkage indices. The soil beneath the strongly inferior crop had platy structure in the 0.05-0.28 m layer and significantly less air-filled specific pore volume in the 0.2-0.4 m layer. This soil structure degradation was caused by seedbed preparation of wet soil, prior to sowing the cotton crop.

scholarly journals Traffic effects on the soil preconsolidation pressure due to eucalyptus harvest operations

2005 ◽  
Vol 62 (3) ◽  
pp. 248-255 ◽  
Author(s):  
Moacir de Souza Dias Junior ◽  
Fernando Palha Leite ◽  
Edson Lasmar Júnior ◽  
Cezar Francisco Araújo Junior
Keyword(s):  
Soil Compaction ◽  
Soil Structure ◽  
Soil Samples ◽  
Compression Tests ◽  
Undisturbed Soil ◽  
Structure Degradation ◽  
Preconsolidation Pressure ◽  
Before And After ◽  
Two Stages ◽  
Wood Transport

One of the limitations for reaching sustainable forest development is related to the traffic of machines and vehicles during harvest operations and wood transport, which may cause soil structure degradation. Seeking a way to analyze this problem, the objective of this study was to determine the traffic effects due to harvest operations and wood transport, on the preconsolidation pressure (sigmap) in a Typic Acrustox cultivated with eucalyptus. This study was conducted using undisturbed soil samples collected at the 0.1-0.125 m depth. Undisturbed soil samples were used in the uniaxial compression tests. Soil sampling consisted of two stages, before and after the mechanized harvest operations. The traffic effects on the sigmap in the dry season indicated that the soil compaction process was neither evident nor important. However, in the rainy season the traffic effects on the sigmap indicated that the operations performed with Harvester and Forwarder caused greater soil compaction than those with Motorized Saw and Manual, which caused less soil compaction.

scholarly journals Effect of Earthing Enhancing Compound (EEC) on Improving Tower Footing Resistance of a 500 kV Tower in a Rocky Area

2021 ◽  
Vol 11 (12) ◽  
pp. 5623
Author(s):  
Nur Alia Farina Mohd Nasir ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Miszaina Osman ◽  
Muhamad Safwan Abd Rahman ◽  
Ungku Anisa Ungku Amirulddin ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Comparative Analysis ◽  
Transmission Line ◽  
Structure Analysis ◽  
Current Distribution ◽  
Soil Profile ◽  
Soil Structure ◽  
Soil Resistivity ◽  
Transmission Towers ◽  
Rocky Soil

This paper presents a comparative analysis of different earthing designs’ performances, with particular interest on the use of earthing enhancing compound (EEC) for a selected earthing design of 500 kV transmission towers in a rocky soil, using the SESCAD tool of the Current distribution, electromagnetic field grounding and soil structure analysis (CDEGS) software. The simulation included the interpretation of soil profile and comparison between designs A, B and C, which are currently used for the 500 kV tower footing resistance (TFR) improvement. Results showed each design had reduced the TFR by 66%, 54.7% and 63.2% for the towers T42, T48 and T50, respectively. In some cases, further improvement of TFR is required, especially in the rocky area where the soil resistivity (SR) value is of more than 500 Ω⋅m. In this case, EEC was used in Design C, encasing both the vertical and horizontal electrodes, and it reduced the TFR further by 16% to 20%. The characteristics of the soil and earthing arrangement design play an important role in achieving a low TFR value, which is directly proportional to the backflashover occurrence and thus to the transmission line performance.

scholarly journals Titanium Carbide Nanocrystals Synthesized from a Metatitanic Acid-Sucrose Precursor via a Carbothermal Reduction

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Hyunho Shin ◽  
Jun-Ho Eun
Keyword(s):  
Process Control ◽  
Titanium Carbide ◽  
Specific Surface ◽  
Surface Area ◽  
Pore Volume ◽  
Carbothermal Reduction ◽  
Crystal Size ◽  
Reduction Process ◽  
Specific Pore Volume ◽  
Metatitanic Acid

A TiC powder is synthesized from a micron-sized mesoporous metatitanic acid-sucrose precursor (precursor M) by a carbothermal reduction process. Control specimens are also prepared using a nanosized TiO2-sucrose precursor (precursor T) with a higher cost. When synthesized at 1500°C for 2 h in flowing Ar, the characteristics of the synthesized TiC from precursor M are similar to those of the counterpart from precursor T in terms of the crystal size (58.5 versus 57.4 nm), oxygen content (0.22 wt% versus 0.25 wt%), and representative sizes of mesopores: approximately 2.5 and 19.7–25.0 nm in both specimens. The most salient differences of the two specimens are found in the TiC from precursor M demonstrating (i) a higher crystallinity based on the distinctive doublet peaks in the high-two-theta XRD regime and (ii) a lower specific surface area (79.4 versus 94.8 m2/g) with a smaller specific pore volume (0.1 versus 0.2 cm3/g) than the counterpart from precursor T.

Developmental Responses to Water and Salinity in Root Systems

2019 ◽  
Vol 35 (1) ◽  
pp. 239-257 ◽  
Author(s):  
José R. Dinneny
Keyword(s):  
Soil Structure ◽  
Root Systems ◽  
Developmental Pathways ◽  
Limiting Factor ◽  
Branching Pattern ◽  
Crop Water ◽  
Primary Mechanism ◽  
Use Efficiency ◽  
Developmental Responses ◽  
Growing Population

Roots provide the primary mechanism that plants use to absorb water and nutrients from their environment. These functions are dependent on developmental mechanisms that direct root growth and branching into regions of soil where these resources are relatively abundant. Water is the most limiting factor for plant growth, and its availability is determined by the weather, soil structure, and salinity. In this review, we define the developmental pathways that regulate the direction of growth and branching pattern of the root system, which together determine the expanse of soil from which a plant can access water. The ability of plants to regulate development in response to the spatial distribution of water is a focus of many recent studies and provides a model for understanding how biological systems utilize positional cues to affect signaling and morphogenesis. A better understanding of these processes will inform approaches to improve crop water use efficiency to more sustainably feed a growing population.

Earthquake Microzoning from Soil Properties

1993 ◽  
Vol 9 (2) ◽  
pp. 209-231 ◽  
Author(s):  
A. P. W. Hodder ◽  
M. Z. Graham
Keyword(s):  
Shear Strength ◽  
New Zealand ◽  
Linear Regression ◽  
Soil Properties ◽  
Shear Wave Velocity ◽  
Soil Type ◽  
Soil Profile ◽  
Soil Structure ◽  
Viscous Damping ◽  
Extent Of Damage

The extent of damage caused by an earthquake in Wellington, New Zealand, in 1968 to buildings erected on a variety of regoliths and foundation materials is correlated with the thickness of the regolith, the depth to the water table and semi-quantitative parameters derived from soil profile descriptions, particularly related to soil type and soil structure. From linear regression correlations, the expected damage for a comparable earthquake elsewhere can be determined. The model was tested for soil data for the Edgecumbe area, hit by a damaging earthquake in 1987. The predictions were sufficiently in accord with observations to suggest that soil properties that reflect the geotechnical properties of the upper parts of the regolith, particularly those that measure the shear strength, shear wave velocity and viscous damping of that material, may be useful for earthquake microzoning purposes in areas where there is a considerable thickness of unconsolidated materials above bedrock.

scholarly journals Soil compaction during harvest operations in five tropical soils with different textures under eucalyptus forests

2018 ◽  
Vol 42 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Paula Cristina Caruana Martins ◽  
Moacir de Souza Dias Junior ◽  
Ayodele Ebenezer Ajayi ◽  
Ernesto Norio Takahashi ◽  
Diego Tassinari
Keyword(s):  
Bearing Capacity ◽  
Soil Compaction ◽  
Sandy Loam ◽  
Traffic Intensity ◽  
Compression Tests ◽  
Load Bearing Capacity ◽  
Undisturbed Soil ◽  
Load Bearing ◽  
Structure Degradation ◽  
Precompression Stress

ABSTRACT Traffic of farm machinery during harvest and logging operations has been identified as the main source of soil structure degradation in forestry activity. Soil susceptibility to compaction and the amount of compaction caused by each forest harvest operation differs according to a number of factors (such as soil strength, soil texture, kind of equipment, traffic intensity, among many others), what requires the adequate assessment of soil compaction under different traffic conditions. The objectives of this study were to determine the susceptibility to compaction of five soil classes with different textures under eucalyptus forests based on their load bearing capacity models; and to determine, from these models and the precompression stresses obtained after harvest operations, the effect of traffic intensity with different equipment in the occurrence of soil compaction. Undisturbed soil samples were collected before and after harvest operations, being then subjected to uniaxial compression tests to determine their precompression stress. The coarse-textured soils were less resistant and endured greater soil compaction. In the clayey LVd2, traffic intensity below four Forwarder passes limited compaction to a third of the samples, whereas in the sandy loam PVd all samples from the 0-3 cm layer were compacted regardless of traffic intensity. The Feller Buncher and the Clambunk presented a high potential to cause soil compaction even with only one or two passes. The use of soil load bearing capacity models and precompression stress determined after harvest and logging operations allowed insight into the soil compaction process in forestry soils.

scholarly journals A new soil core sampler for determination bulk density in soil profile

2011 ◽  
Vol 50 (No. 6) ◽  
pp. 250-256 ◽  
Author(s):  
P. Prikner ◽  
F. Lachnit ◽  
F. Dvořák
Keyword(s):  
Bulk Density ◽  
Soil Sample ◽  
Soil Profile ◽  
Soil Compaction ◽  
Sampling Methods ◽  
Sample Volume ◽  
Soil Core ◽  
Sample Collection ◽  
Core Sampler ◽  
Inner Diameter

The portable soil core sampler was engineered for gradual sampling of soil profile in the depth up to 0.5 m, which ensures extraction of the whole sample volume of soil profile in determinable depth. The portable soil core sampler was compared with the professional soil probe Eijkelkamp P1.31 (Eijkelkamp Agrisearch Equipment, Netherlands) in field conditions. The portable sampler was compared with the physical soil sample rings in laboratory conditions to eliminate all of possible restrictive aspects affecting the procedure of measurement. The portable soil core sampler with inner diameter 71 mm, depth 120 mmenables gradually take samples of soil profile by step of 50 mmand is able to detect possible local extremes. On the other hand a soil probe is not able to reach desired accuracy in taking of a&nbsp;soil sample. Values measured from a soil probe approximately taken by step of 150 mmare inaccurate. The values of bulk density of both sampling methods were variable at significant interval from 40 into 80 kg/m<sup>3</sup>. Different values could be caused by soil profile condition and by the use of different sampling methods. The design of a portable soil sampler should be of assistance in fast and precise soil profiling sample collection, which is required to determine bulk density of the soil, its variance depending on moisture content in soil compaction determining criteria.

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