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 Model Averaging and Its Use in Economics

2020 ◽  
Vol 58 (3) ◽  
pp. 644-719 ◽  
Author(s):  
Mark F. J. Steel
Keyword(s):  
Model Uncertainty ◽  
Bayesian Model Averaging ◽  
Model Averaging ◽  
Linear Regression Models ◽  
Bayesian Procedures ◽  
Wide Range ◽  
Computational Resources ◽  
Production Modeling ◽  
Frequentist Model Averaging

The method of model averaging has become an important tool to deal with model uncertainty, for example in situations where a large amount of different theories exist, as are common in economics. Model averaging is a natural and formal response to model uncertainty in a Bayesian framework, and most of the paper deals with Bayesian model averaging. The important role of the prior assumptions in these Bayesian procedures is highlighted. In addition, frequentist model averaging methods are also discussed. Numerical techniques to implement these methods are explained, and I point the reader to some freely available computational resources. The main focus is on uncertainty regarding the choice of covariates in normal linear regression models, but the paper also covers other, more challenging, settings, with particular emphasis on sampling models commonly used in economics. Applications of model averaging in economics are reviewed and discussed in a wide range of areas including growth economics, production modeling, finance and forecasting macroeconomic quantities. (JEL C11, C15, C20, C52, O47).

Effect of Macroporosity on Physical Property Estimates for Peat Soils

2021 ◽  
Author(s):  
Miaorun Wang ◽  
Haojie Liu ◽  
Bernd Lennartz
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Total Porosity ◽  
Pedotransfer Functions ◽  
Parameter Estimates ◽  
Model Parameters ◽  
Soil Water Retention ◽  
Peat Soils ◽  
Undisturbed Soil ◽  
Wide Range

<p>Hydrophysical soil properties play an important role in regulating the water balance of peatlands and are known to be a function of the status of peat degradation. The objective of this study was to revise multiple regression models (pedotransfer functions, PTFs) for the assessment of hydrophysical properties from readily available soil properties. We selected three study sites, each representing a different state of peat degradation (natural, degraded and extremely degraded). At each site, 72 undisturbed soil cores were collected. The saturated hydraulic conductivity (<em>K</em><sub>s</sub>), soil water retention curves, total porosity, macroporosity, bulk density (BD) and soil organic matter (SOM) content were determined for all sampling locations. The van Genuchten (VG) model parameters (<em>θ</em><sub>s</sub>, <em>α</em>, <em>n</em>) were optimized using the RETC software package. Macroporosity and the <em>K</em><sub>s</sub> were found to be highly correlated, but the obtained functions differ for differently degraded peatlands. The introduction of macroporosity into existing PTFs substantially improved the derivation of hydrophysical parameter values as compared to functions based on BD and SOM content alone. The obtained PTFs can be applied to a wide range of natural and degraded peat soils. We assume that the incorporation of macroposity helps to overcome effects possibly resulting from soil management. Our results suggest that the extra effort required to determine macroporosity is worth it, considering the quality of parameter estimates for hydraulic conductivity as well as the soil hydraulic VG model.</p>

scholarly journals Combination of Measurement Methods for a Wide-Range Description of Hydraulic Soil Properties

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1021 ◽  
Author(s):  
Thomas Weninger ◽  
Gernot Bodner ◽  
Janis Kreiselmeier ◽  
Parvathy Chandrasekhar ◽  
Stefan Julich ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Soil Water ◽  
Water Retention ◽  
Measurement Methods ◽  
Water Dynamics ◽  
Conductivity Measurements ◽  
Soil Water Dynamics ◽  
Evaporation Method ◽  
Wide Range

Established measurement methods for hydraulic soil properties cover a limited soil moisture range. Simulations of soil water dynamics based on such observations are therefore rarely representative for all conditions from saturation to drought. Recent technical developments facilitate efficient and cheap collecting of soil water characteristics data, but the quantitative benefit of extended measurement campaigns has not been adequately tested yet. In this study, a combination of four methods to measure water retention and hydraulic conductivity at different moisture ranges was applied. Evaporation method, dewpoint psychrometry, hood infiltrometer experiments, and falling head method for saturated conductivity were conducted at two experimental sites in eastern Austria. Effects of including the particular methods in the measurement strategy were examined by visual evaluation and a 1D-modelling sensitivity study including drainage, infiltration and drought conditions. The evaporation method was considered essential due to its broad measurement range both for water retention and hydraulic conductivity. In addition to that, the highest effect on simulated water balance components was induced by the inclusion of separate conductivity measurements near saturation. Water content after three days of drainage was 15 percent higher and the transpiration rate in a drought period was 22 percent higher without near-saturated conductivity measurements. Based on relative comparisons between different combinations, we suggested combining evaporation method and hood infiltrometer experiments as the basis for representative predictions of soil water dynamics.

Unravelling the effects of soil properties on water infiltration: segmented quantile regression on a large data set from arid south-west Africa

Soil Research ◽  
2006 ◽  
Vol 44 (8) ◽  
pp. 783 ◽  
Author(s):  
A. J. Mills ◽  
M. V. Fey ◽  
A. Gröngröft ◽  
A. Petersen ◽  
T. V. Medinski
Keyword(s):  
Quantile Regression ◽  
Soil Properties ◽  
Fine Sand ◽  
Additive Models ◽  
Water Soluble ◽  
Statistical Analyses ◽  
Organic C ◽  
Water Dispersible ◽  
Wide Range

Relationships were sought between infiltrability and the properties of hundreds of surface soils (pedoderms) sampled across Namibia and western South Africa. Infiltrability was determined using a laboratory method, calibrated against a rainfall simulator, which measures the passage of a suspension of soil in distilled water through a small column packed with the same soil. Other properties determined were EC, pH, water-soluble cations and anions, ammonium acetate-extractable cations, organic C, total N, a 7-fraction particle size distribution, water-dispersible silt and clay, and clay mineral composition. Our objective was to ascertain whether general principles pertaining to infiltrability can be deduced from an analysis of a wide diversity of soils. To achieve this we compared correlation analysis, generalised linear models (GLMs), and generalised additive models (GAMs) with a segmented quantile regression approach, in which parametric regression lines were fitted to the 0.9 and 0.1 quantile values of equal subpopulations based on the x variable. Quantile regression demarcated relational envelopes enclosing four-fifths of the data points. The envelopes revealed ranges for soil properties over which infiltrability is potentially maximal (spread over a wide range) or predictably minimal (confined to small values). The r2 value of the 0.9 quantile regression line was taken as an index of reliability in being able to predict limiting effects on infiltrability associated with a variety of soil properties. Prediction of infiltration was most certain from textural properties, especially the content of water-dispersible silt (r2 = 0.96, n = 581), water-dispersible clay (0.88, n = 581), very fine sand (0.86, n = 174), and medium sand (0.84, n = 174). Chemical properties such as EC, sodium status, organic C content, and clay mineralogy were less clearly related to infiltrability than was texture. The role of fine-particle dispersion in blocking pores was highlighted by the stronger prediction in all statistical analyses provided by the water-dispersible as opposed to total content of silt and clay. All the statistical analyses revealed a probable skeletal role of medium and fine sand fractions in shaping pores and a plasmic (mobile) role of finer fractions in blocking pores. A noteworthy discovery was an apparent switch in role from skeletal to plasmic at a particle diameter of about 0.1 mm (i.e. between fine and very fine sand).

scholarly journals Co-evolution hints at soil microbial biomass as the entity of soil fertility

2015 ◽  
Author(s):  
Masato Oda ◽  
Yasukazu Hosen ◽  
Uchada Sukchan
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Soil Properties ◽  
Crop Yield ◽  
Soil Microbial Biomass ◽  
Crop Yields ◽  
Plant Biomass ◽  
Total N ◽  
Soil Microbial ◽  
Wide Range

Nitrogen (N) and Carbon (C) are popular indicators of soil fertility; however, they are not soil fertility itself. In fact, they may be seen as just two aspects of the one entity. Soil microbial biomass (SMB) is also one of soil fertility indicators; furthermore, recent study of co-evolution between plants and microorganisms raises an idea that SMB might be the entity of fertility. The correlation between SMB and crop yield has been found in some studies but not in others. Those studies were conducted from the standpoint of N stock balance; therefore, the correlation between soil properties before planting and plant yields were analyzed. Here, we show—in our analysis of harvest-time soil properties and crop yields—that SMB correlates more strongly than inorganic N, total N, or total C with average crop yield under a wide range of cultivation conditions. From the viewpoint of co-evolution, plant biomass is a part of the plant and soil microorganism system; therefore, increasing SMB will balance by increasing plant biomass. In addition, the SMB could increase independently from the plant growth by artificial organic matter input. This concept will break through the yield limitation of conventional farming.

scholarly journals Co-evolution hints at soil microbial biomass as the entity of soil fertility

2015 ◽  
Author(s):  
Masato Oda ◽  
Yasukazu Hosen ◽  
Uchada Sukchan
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Soil Properties ◽  
Crop Yield ◽  
Soil Microbial Biomass ◽  
Crop Yields ◽  
Plant Biomass ◽  
Total N ◽  
Soil Microbial ◽  
Wide Range

Nitrogen (N) and Carbon (C) are popular indicators of soil fertility; however, they are not soil fertility itself. In fact, they may be seen as just two aspects of the one entity. Soil microbial biomass (SMB) is also one of soil fertility indicators; furthermore, recent study of co-evolution between plants and microorganisms raises an idea that SMB might be the entity of fertility. The correlation between SMB and crop yield has been found in some studies but not in others. Those studies were conducted from the standpoint of N stock balance; therefore, the correlation between soil properties before planting and plant yields were analyzed. Here, we show—in our analysis of harvest-time soil properties and crop yields—that SMB correlates more strongly than inorganic N, total N, or total C with average crop yield under a wide range of cultivation conditions. From the viewpoint of co-evolution, plant biomass is a part of the plant and soil microorganism system; therefore, increasing SMB will balance by increasing plant biomass. In addition, the SMB could increase independently from the plant growth by artificial organic matter input. This concept will break through the yield limitation of conventional farming.

scholarly journals Co-evolution hints at soil microbial biomass as the entity of soil fertility

2015 ◽  
Author(s):  
Masato Oda ◽  
Yasukazu Hosen ◽  
Uchada Sukchan
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Soil Properties ◽  
Crop Yield ◽  
Soil Microbial Biomass ◽  
Crop Yields ◽  
Plant Biomass ◽  
Total N ◽  
Soil Microbial ◽  
Wide Range

Nitrogen (N) and Carbon (C) are popular indicators of soil fertility; however, they are not soil fertility itself. In fact, they may be seen as just two aspects of the one entity. Soil microbial biomass (SMB) is also one of soil fertility indicators; furthermore, recent study of co-evolution between plants and microorganisms raises an idea that SMB might be the entity of fertility. The correlation between SMB and crop yield has been found in some studies but not in others. Those studies were conducted from the standpoint of N stock balance; therefore, the correlation between soil properties before planting and plant yields were analyzed. Here, we show—in our analysis of harvest-time soil properties and crop yields—that SMB correlates more strongly than inorganic N, total N, or total C with average crop yield under a wide range of cultivation conditions. From the viewpoint of co-evolution, plant biomass is a part of the plant and soil microorganism system; therefore, increasing SMB will balance by increasing plant biomass. In addition, the SMB could increase independently from the plant growth by artificial organic matter input. This concept will break through the yield limitation of conventional farming.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Introduction: Emotion, History and the Arts

2018 ◽  
Vol 7 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Erin Sullivan ◽  
Marie Louise Herzfeld-Schild
Keyword(s):  
Historical Change ◽  
Carson Mccullers ◽  
Emotional Life ◽  
Review Section ◽  
The Arts ◽  
Wide Range ◽  
War Correspondents ◽  
History Of ◽  
Johan Huizinga

This introduction surveys the rise of the history of emotions as a field and the role of the arts in such developments. Reflecting on the foundational role of the arts in the early emotion-oriented histories of Johan Huizinga and Jacob Burkhardt, as well as the concerns about methodological impressionism that have sometimes arisen in response to such studies, the introduction considers how intensive engagements with the arts can open up new insights into past emotions while still being historically and theoretically rigorous. Drawing on a wide range of emotionally charged art works from different times and places—including the novels of Carson McCullers and Harriet Beecher-Stowe, the private poetry of neo-Confucian Chinese civil servants, the photojournalism of twentieth-century war correspondents, and music from Igor Stravinsky to the Beatles—the introduction proposes five ways in which art in all its forms contributes to emotional life and consequently to emotional histories: first, by incubating deep emotional experiences that contribute to formations of identity; second, by acting as a place for the expression of private or deviant emotions; third, by functioning as a barometer of wider cultural and attitudinal change; fourth, by serving as an engine of momentous historical change; and fifth, by working as a tool for emotional connection across communities, both within specific time periods but also across them. The introduction finishes by outlining how the special issue's five articles and review section address each of these categories, while also illustrating new methodological possibilities for the field.

Short Films from a Small Nation

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
Public Information ◽  
Industrial Process ◽  
Actor Network Theory ◽  
Documentary Films ◽  
Wide Range ◽  
Short Films ◽  
Post War ◽  
The 1960S ◽  
Art And Architecture

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.

Sign in / Sign up

Export Citation Format

Share Document