The relationship between aggregation and other soil properties in cracking clay soils

Soil Research ◽  
1984 ◽  
Vol 22 (1) ◽  
pp. 59 ◽  
Author(s):  
KJ Coughlan ◽  
RJ Loch
Keyword(s):  
Hydraulic Conductivity ◽  
Salt Content ◽  
Chemical Properties ◽  
Aggregate Size ◽  
Strong Relationship ◽  
Clay Soils ◽  
Coarse Surface ◽  
Seedbed Preparation ◽  
The Relationship ◽  
Dispersion Ratio

This paper explores the processes responsible for clay dispersion, and the formation of large dry aggregates, in cracking clay soils. It also isolates the soil factors causing variations in dry aggregate size using regression analysis. Twelve cracking clay soil samples were selected on visual differences in dry aggregate size distribution following seedbed preparation, and a range of soil structural and chemical properties were measured. The per cent dry aggregates > 5 mm was found to increase with resistance to mechanical abrasion, stability to wet sieving after capillary wetting, and dispersion ratio, indicating that large dry aggregates are formed as a result of binding by dispersed clay. Both raindrop impact and puddling by cultivation may be involved in dispersion. There was a strong relationship between dry aggregate size in the 0-10 cm layer and salt content in the subsurface (60-90 cm) layer. Coarse surface aggregation is explained in terms of limited profile hydraulic conductivity. For the soils studied, the properties of the surface layer appear to be responsible, at least in part, for the limitation in profile hydraulic conductivity. Dry aggregate size in the 0-10 cm layer was not simply correlated with any of the chemical properties of that layer. However, equations containing two (ESP and CEC per gram of clay) or three (ESP, per cent clay and CEC) independent variables were derived to explain variations in dry aggregate size, both for the 12 soils studied and for a wider range of Queensland cracking clay soils.

scholarly journals EKSPLORASI MIKORIZA ARBUSKULA PADA BEBERAPA KEDALAMAN TANAH DI PERAKARAN RUMPUT BANTENG PADA LAHAN PASCATAMBANG

2021 ◽  
Vol 8 (2) ◽  
pp. 341-347
Author(s):  
Yhudo Tomo ◽  
Budi Prasetya
Keyword(s):  
Heavy Metals ◽  
Population Density ◽  
Plant Growth ◽  
Soil Ph ◽  
Arbuscular Mycorrhizae ◽  
Soil Depth ◽  
Chemical Properties ◽  
Arbuscular Mycorrhizal ◽  
Strong Relationship ◽  
The Relationship

The presence of mycorrhizae can reduce the level of poisoning caused by heavy metals in post-mining land and support plant growth. Post-mining land is generally only a few types of mycorrhizae that can adapt, especially post-mining land. This research was conducted to determine the presence, types and distribution of mycorrhizae as well as the relationship between soil depth and mycorrhizal distribution and soil chemical properties at various depths in the rhizosphere of bull grass as the dominant vegetation in post-coal mining land. The results showed that there were arbuscular mycorrhizae at each soil depth with different population density levels, namely 273 spores 100 g-1 soil at a depth of 0 - 10 cm (K10); 239 spores 100 g-1 soil at a depth of 10 – 20 cm (K20) and 155 spores 100 g-1 soil at a depth of 20 – 30 cm (K30). The arbuscular mycorrhizae found at all soil depths are of the same type, which is included in the genus Glomus. Soil depth with the number of arbuscular mycorrhizal distribution (r count -0.7754> r table -0.4973) has a very strong relationship and with soil pH (r count -0.6309> r table -0.4973) has a strong relationship. The number of distribution of arbuscular mycorrhizae with soil pH (r count 0.5943> r table 0.4973) has a strong relationship

Energetic relationships for crushing of soil clods

2006 ◽  
Vol 2 (1) ◽  
pp. 51-72
Author(s):  
István Patay ◽  
Virág Sándor
Keyword(s):  
Moisture Content ◽  
Specific Energy ◽  
Soil Moisture Content ◽  
Energy Requirement ◽  
Clay Content ◽  
Clay Soils ◽  
Rigid Support ◽  
Soil Plasticity ◽  
Specific Energy Requirement ◽  
The Relationship

Clod crushing is a principal problem with soils of high clay content. Therefore, there is a need for determining the conditions for clod breaking and clod crushing. The objective of the work was to develop a special purpose tool for single clod breaking both by rigid support of the clod and by a single clod supported by soil and to develop a machine for clod crushing. Furthermore, the purpose was to determine the relationship between the specific energy requirement for clod crushing in the function of soil plasticity and the soil moisture content by the means of the developed tool and machine. The main result of the experiments is summarized in a 3D diagram where the specific energy requirement for soil clod crushing is given in the function of the moisture content and the plasticity index for different clay soils.

THE EFFECT OF TRADE RECEIVABLES ON THE LIQUIDITY OF THE COMPANY PT. GRAHA TUMARIMA, CITY OF SUKABUMI

2020 ◽  
Author(s):  
endang naryono
Keyword(s):  
Correlation Analysis ◽  
Hypothesis Testing ◽  
Sampling Technique ◽  
Strong Relationship ◽  
T Test ◽  
Financial Statement ◽  
Positive Meaning ◽  
The Relationship ◽  
Purposive Sample ◽  
Analysis Determination

This study examines the influence of receivables on liquidity at PT. Graha Tumarima. Sukabumi City for 5 years, with a sampling technique using a purposive sample in the form of financial statement data from 2010 to 2014 using a table of trade receivables and company liquidity. In this study, researchers refer to the theory of Bambang Riyanto (2008: 94) as the connecting theory of the title. This study aims to determine whether there is a relationship and influence between receivables and liquidity at PT. Graha Tumarima. The research design uses the method of exposing the facto, the method of data collection aims to test the hypothesis by using correlation analysis, determination, regression and hypothesis testing with t-test. The results of this study show the influence of receivables on liquidity is shown by the value of r = 0.888, meaning that receivables have a very strong relationship to liquidity. The nature of the relationship is positive, meaning that if the value of cooperative credit is higher the liquidity will be higher. Conversely, if the value of receivables decreases, liquidity will decrease. The magnitude of the influence of receivables on liquidity is shown by the value of R Square / Determination Coefficient of 0.789 or 78.9% thus the receivables have an effect of 78.9% on cooperative liquidity. Hypothesis testing uses the t test, that t arithmetic = 3.347 while t table = 3.182 means t arithmetic> t table. Means that Ho is rejected and Ha is accepted. There is an influence between the receivables on liquidity at PT. Graha Tumarima, Sukabumi City

Development and evaluation of trans-Amadi groundwater parameters: The integration of finite element techniques

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Finite Element ◽  
Polynomial Regression ◽  
Nitrate Concentration ◽  
Strong Relationship ◽  
Total Iron ◽  
Coefficient Of Determination ◽  
Port Harcourt ◽  
Polynomial Expression ◽  
The Relationship ◽  
Best Fit

Mathematical model was developed and evaluated to monitor and predict the groundwater characteristics of Trans-amadi region in Port Harcourt City. In this research three major components were considered such as chloride, total iron and nitrate concentration as well as the polynomial expression on the behavious on the concentration of each component was determined in terms of the equation of the best fit as well as the square root of the curve. The relationship between nitrate and distance traveled by Nitrate concentration by the model is given as Pc = 0.003x2 - 0.451x + 14.91with coefficient of determination, R² = 0.947, Chloride given as Pc = 0.000x2 - 0.071x + 2.343, R² = 0.951while that of Total Iron is given as Pc = 2E-05x2 - 0.003x + 0.110, R² = 0.930. All these show a strong relationship as established by Polynomial Regression Model. The finite element techniques are found useful in monitoring, predicting and simulating groundwater characteristics of Trans-amadi as well as the prediction on the variation on the parameters of groundwater with variation in time.

Assessment of the Role of Different Soil Properties on Crust Strength by Linear Regression Models

2019 ◽  
Vol 6 (04) ◽  
Author(s):  
MINAKSHI SERAWAT ◽  
V K PHOGAT ◽  
ANIL Abdul KAPOOR ◽  
VIJAY KANT SINGH ◽  
ASHA SERAWAT
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Crop Yields ◽  
Modulus Of Rupture ◽  
Silty Clay ◽  
Linear Regression Models ◽  
Wide Range ◽  
Dispersion Ratio ◽  
Crust Strength

Soil crust strength influences seedling emergence, penetration and morphology of plant roots, and, consequently, crop yields. A study was carried out to assess the role of different soil properties on crust strength atHisar, Haryana, India. The soil samples from 0-5 and 5-15 cm depths were collected from 21 locations from farmer’s fields, having a wide range of texture.Soil propertieswere evaluated in the laboratory and theirinfluence on the modulus of rupture (MOR), which is the measure of crust strength, was evaluated.The MOR of texturally different soils was significantly correlated with saturated hydraulic conductivity at both the depths. Dispersion ratio was found to decrease with an increase in fineness of the texture of soil and the lowest value was recorded in silty clay loam soil,which decreased with depth. The modulus of rupture was significantly negatively correlative with the dispersion ratio.There was no role of calcium carbonate in influencing the values of MOR of soils. Similarly,the influence of pH, EC and SAR of soil solution on MOR was non-significant.A perusal of thevalues of the correlations between MOR and different soil properties showed that the MOR of soils of Haryana are positively correlated with silt + clay (r = 0.805) followed by water-stable aggregates (r = 0.774), organic carbon (r = 0.738), silt (r = 0.711), mean weight diameter (r = 0.608) and clay (r = 0.593) while negatively correlated with dispersion ratio (r = - 0.872), sand (r = -0.801) and hydraulic conductivity (r = -0.752) of soils.

scholarly journals Hydraulic and Swell–Shrink Characteristics of Clay and Recycled Zeolite Mixtures for Liner Construction in Sustainable Waste Landfill

2021 ◽  
Vol 13 (13) ◽  
pp. 7301
Author(s):  
Marcin K. Widomski ◽  
Anna Musz-Pomorska ◽  
Wojciech Franus
Keyword(s):  
Hydraulic Conductivity ◽  
Exchange Capacity ◽  
Saturated Hydraulic Conductivity ◽  
Clay Soils ◽  
Compacted Clay ◽  
Clay Liner ◽  
Compacted Clay Liner ◽  
Drying And Rewetting ◽  
Swelling Characteristics ◽  
Shrinkage And Swelling

This paper presents research considering hydraulic as well as swelling and shrinkage characteristics of potential recycled fine particle materials for compacted clay liner for sustainable landfills. Five locally available clay soils mixed with 10% (by mass) of NaP1 recycled zeolite were tested. The performed analysis was based on determined plasticity, cation exchange capacity, coefficient of saturated hydraulic conductivity after compaction, several shrinkage and swelling characteristics as well as, finally, saturated hydraulic conductivity after three cycles of drying and rewetting of tested specimens and the reference samples. The obtained results showed that addition of zeolite to clay soils allowed reduction in their saturated hydraulic conductivity to meet the required threshold (≤1 × 10−9 m/s) of sealing capabilities for compacted clay liner. On the other hand, an increase in plasticity, swelling, and in several cases in shrinkage, of the clay–zeolite mixture was observed. Finally, none of the tested mixtures was able to sustain its sealing capabilities after three cycles of drying and rewetting. Thus, the studied clayey soils mixed with sustainable recycled zeolite were assessed as promising materials for compacted liner construction. However, the liner should be operated carefully to avoid extensive dissication and cracking.

scholarly journals Tourism Industry and Economic Growth Nexus in Beijing, China

Economies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 25 ◽  
Author(s):  
Yang Songling ◽  
Muhammad Ishtiaq ◽  
Bui Thi Thanh
Keyword(s):  
Economic Growth ◽  
Economic Development ◽  
Strong Support ◽  
Growth Index ◽  
Strong Relationship ◽  
Tourism Industry ◽  
Var Model ◽  
Long Run ◽  
The Relationship ◽  
Beijing China

In the developing economy, tourism is the most visible and steadiest growing facade. Tourism is considered one of the rapidly increasing elements for economic development from the last two decades. Therefore, the proposed study used vector autoregression (VAR) model, error correction model (ECM), and the Granger causality to check the relationship between the tourism industry and economic growth based on the data of the Beijing municipal bureau of statistics from 1994 to 2015. Gross domestic product (GDP) is used as a replacement variable for the economic growth index, while internal tourism revenue is used as a tourism industry indicator. The study supports the tourism-led growth hypothesis proposed in the existing literature in a different survey of tourism and economic development. The results show that there is a strong relationship in the tourism industry and economic growth in the context of Beijing, and at the same time, tourism creates a more significant increase in long run local real economic accomplishments. The results of the VAR model confirm that in the long run, Beijing’s economic growth is affected by domestic tourism, while the ECM model shows unidirectional results in the short term. Similarly, there is a one-way causal relationship between the tourism industry and economic growth in Beijing, China. The empirical results are in strong support of the concept that tourism causes growth.

scholarly journals Treated wastewater irrigation effects on soil hydraulic conductivity and aggregate stability of loamy soils in Israel

2015 ◽  
Vol 63 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Karsten Schacht ◽  
Bernd Marschner
Keyword(s):  
Hydraulic Conductivity ◽  
Chemical Properties ◽  
Aggregate Stability ◽  
Treated Wastewater ◽  
Soil Aggregate Stability ◽  
Irrigation Effects ◽  
Physical And Chemical ◽  
The Impact

Abstract The use of treated wastewater (TWW) for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW) resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC) and soil aggregate stability (SAS). To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm) were collected for analyzing SAS and determination of selected soil chemical and physical characteristics. The mean HC values decreased at all TWW sites by 42.9% up to 50.8% compared to FW sites. The SAS was 11.3% to 32.4% lower at all TWW sites. Soil electrical conductivity (EC) and exchangeable sodium percentage (ESP) were generally higher at TWW sites. These results indicate the use of TWW for irrigation is a viable, but potentially deleterious option, as it influences soil physical and chemical properties.

Generational Change and Continuity in British Partisan Choice

1976 ◽  
Vol 6 (3) ◽  
pp. 364-368
Author(s):  
Paul R. Abramson
Keyword(s):  
Social Class ◽  
Strong Relationship ◽  
Political Life ◽  
Generational Change ◽  
The 1960S ◽  
The Relationship

The strong relationship between social class and partisan choice is one of the most extensively documented facts of British political life; but that relationship declined markedly during the 1960s, as Butler and Stokes have shown. Their lucid documentation of the declining class–party nexus is among the major findings of the second edition of their book, and, as class-based partisanship is particularly low among the young, many might conclude that the relationship between class and party will continue to decline in future. It would, however, be premature to reach this conclusion.

Cold tolerance of the Antarctic springtail Gomphiocephalus hodgsoni (Collembola, Hypogastruridae)

2001 ◽  
Vol 13 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Brent J. Sinclair ◽  
Heidi Sjursen
Keyword(s):  
Cold Tolerance ◽  
Thermal Environment ◽  
Strong Relationship ◽  
Dry Weight ◽  
Glycerol Content ◽  
Recrystallization Inhibition ◽  
Low Levels ◽  
Inhibition Studies ◽  
The Antarctic ◽  
The Relationship

Cold tolerance of the springtail Gomphiocephalus hodgsoni Carpenter (Collembola: Hypogastruridae) was studied at Cape Bird, Ross Island, Antarctica (77°13′S, 166°26′E). Microclimate temperatures indicate a highly seasonal thermal environment, with winter minima <–39°C. Snow cover significantly buffers both minimum temperatures and cooling rates. Gomphiocephalus hodgsoni survives low temperatures by avoiding freezing. Mean low group supercooling points (SCPs) ranged from –35.4°C in October to –28.3°C in January. The lowest SCP measured was –38.0°C. The high SCP group was very small, making up only 18% of the population in January. In October, G. hodgsoni had a very high glycerol content (>80 μg mg−1 dry weight), although this declined rapidly to low levels (c. 7–10 μg mg−1 dry weight) in January. Quantities of glucose and trehalose were low during October, but steadily increased throughout the summer. Haemolymph osmolality was exceptionally high (up to 1755 mOsm kg−1) at the end of November, but this rapidly declined to c. 500 mOsm kg−1 by late December. The presence of thermal hystersis proteins was indicated by both osmometry on haemolymph samples and recrystallization inhibition studies of springtail homogenates. There was a strong relationship between glycerol content and SCP, but the relationship between haemolymph osmolality, SCP and carbohydrates is uncertain.

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