Sodicity and soil structure

Soil Research ◽  
1991 ◽  
Vol 29 (6) ◽  
pp. 935 ◽  
Author(s):  
P Rengasamy ◽  
KA Olsson
Keyword(s):  
Soil Structure ◽  
Plant Performance ◽  
Sodic Soils ◽  
Electrolyte Conductivity ◽  
Soil Solutions ◽  
Biological Amelioration ◽  
Soil Behaviour ◽  
Poor Soil

Sodic soils are widespread in Australia reflecting the predominance of sodium chloride in groundwaters and soil solutions. Sodic soils are subject to severe structural degradation and restrict plant performance through poor soil-water and soil-air relations. Sodicity is shown to be a latent problem in saline-sodic soils where deleterious effects are evident only after leaching profiles free of salts. A classification of sodic soils based on sodium adsorption ratio, pH and electrolyte conductivity is outlined. Current understanding of the processes and the component mechanisms of sodic soil behaviour are integrated to form the necessary bases for practical solutions in the long term and to define areas for research. The principles of organic and biological amelioration of sodicity, as alternatives to costly inorganic amendments, are discussed.

scholarly journals Bodenveränderungen und Typisierung von Fahrspuren nach physikalischer Belastung | Changes in the soil and the classification of ruts according to physical loading

2010 ◽  
Vol 161 (12) ◽  
pp. 504-509 ◽  
Author(s):  
Peter Lüscher
Keyword(s):  
Soil Structure ◽  
Pore Space ◽  
Soil Protection ◽  
Soil Physics ◽  
Physical Loading ◽  
Saturated Water ◽  
Soil Functionality ◽  
Term Maintenance

In Swiss environment legislation, protection of the soil is defined by reference to the long-term maintenance of soil fertility. To fulfil this commitment, long-lasting damage to the soil must be prevented, respectively reduced to a minimum. When the forest floor is driven over with heavy logging machinery, this can lead to profound and long-lasting changes in the soil structure in the ruts thus formed. Based on driving trials under controlled conditions in the Heiteren region of the forest near Bern, investigations were made to find out whether the classification of ruts into three distinct types showing morphologically determined changes in the soil could be substantiated with the help of known values in soil physics. It was shown that the non-compacted reference soils could be clearly distinguished from all three types of rut by comparison of the stratification density, the total pore space and the saturated water permeability. In addition, the three types significantly differed from each other. Damage to the soil can be reduced to a minimum through consequent planning of skidding tracks and by paying due attention to the prevailing humidity of the soil at the time when vehicles are used. Thanks to the connection established between the character of the ruts and soil functionality, the classification of rut types provides a practically relevant and objective instrument for effective physical soil protection.

Management of a sodic soil for wine grape production

2002 ◽  
Vol 42 (3) ◽  
pp. 333 ◽  
Author(s):  
A. D. Wheaton ◽  
B. M. McKenzie ◽  
J. M. Tisdall
Keyword(s):  
Root Growth ◽  
Wheat Straw ◽  
Water Movement ◽  
Block Design ◽  
Water Soluble ◽  
Plant Performance ◽  
Soil Conditions ◽  
Soil Electrical Conductivity ◽  
Sodic Soils ◽  
Poor Soil

Sodic soils, which are widespread in Australian wine growing regions, restrict plant performance through poor soil and water and soil and air relations. In the northern Goulburn Valley of Victoria, an experiment was conducted from 1995 to 1998 in a vineyard block established with Chardonnay on Ramsey rootstock in 1972. The experiment was to improve root growth and vine performance by minimising hardsetting and crusting of the surface soil and decrease its susceptibility to waterlogging by improving water flow into the sodic subsoil. The factorial combinations of gypsum or no–gypsum and wheat straw or ryegrass were applied to the vine line in a randomised block design. The improvement in grapevine performance was attributed to improved soil conditions for root growth and water movement. Soil electrical conductivity (EC) to 500 mm depth was increased by at least 36%, about 15 months after application of 12 t/ha gypsum, and the effect was maintained at least 40 months after application. The increase in EC was associated with a decrease in spontaneous dispersion at these depths. The application of wheat straw to gypsum–treated soil decreased EC by 52% at 200–300 mm depth but concentrations of water–soluble plus exchangeable Ca2+, Mg2+ and total cations were unaffected. The contributions of water–soluble plus exchangeable Ca2+, and water–soluble plus exchangeable Mg2+ by wheat straw to soil (not gypsum–treated) at 200–300 mm depth were apparent, as concentrations were similar to those in gypsum–treated soils without wheat straw. Forty months after application of gypsum, the exchangeable sodium percentage (ESP) was decreased by at least 26% at a depth of at least 500 mm depth. Spontaneous dispersion was greater in soil with wheat straw applied at 0–100 mm depth than in soil with ryegrass grown, and reflects the influence of organic anions from decomposing wheat straw and the ability of ryegrass to stabilise soil. The stabilising ability of gypsum and ryegrass is reinforced by the greater depth of soil maintained at less than 1 MPa penetration resistance in these treatments, as well as an increase in hydraulic conductivity.

MODERN PROBLEMATICS AND ANALYSIS OF EFFICIENCY OF APPLICATION OF DIFFERENT APPROACHES TO DESTRUCTION OF INFORMATION ON MAGNETIC MEDIA

2019 ◽  
Vol 2 (12) ◽  
pp. 154-164
Author(s):  
O. Semenenko ◽  
O. Vodchyts ◽  
V. Koverga ◽  
R. Lukash ◽  
O. Lutsenko
Keyword(s):  
Armed Forces ◽  
Information Storage ◽  
Storage Device ◽  
Magnetic Media ◽  
Long Term Storage ◽  
Physical Impact ◽  
And Storage ◽  
Term Storage

The introduction and active use of information transmission and storage systems in the Ministry of Defense (MoD) of Ukraine form the need to develop ways of guaranteed removal of data from media after their use or long-term storage. Such a task is an essential component of the functioning of any information security system. The article analyzes the problems of guaranteed destruction of information on magnetic media. An overview of approaches to the guaranteed destruction of information on magnetic media of different types is presented, and partial estimates of the effectiveness of their application are given by some generally accepted indicators of performance evaluation. The article also describes the classification of methods of destruction of information depending on the influence on its medium. The results of the analysis revealed the main problems of application of software methods and methods of demagnetization of the information carrier. The issue of guaranteed destruction of information from modern SSD devices, which are actively used in the formation of new systems of information accumulation and processing, became particularly relevant in the article. In today's conditions of development of the Armed Forces of Ukraine, methods of mechanical and thermal destruction are more commonly used today. In the medium term, the vector of the use of information elimination methods will change towards the methods of physical impact by the pulsed magnetic field and the software methods that allow to store the information storage device, but this today requires specialists to develop new ways of protecting information in order to avoid its leakage.

Influence of internal and external risks on sustainability of financial system of Аltai krai

2018 ◽  
Vol 35 (4) ◽  
pp. 133-136
Author(s):  
R. N. Ibragimov
Keyword(s):  
Sustainable Development ◽  
Financial Stability ◽  
Management Strategy ◽  
Financial System ◽  
Risk Management Strategy ◽  
The Sustainable Development ◽  
The Stability ◽  
The Impact

The article examines the impact of internal and external risks on the stability of the financial system of the Altai Territory. Classification of internal and external risks of decline, affecting the sustainable development of the financial system, is presented. A risk management strategy is proposed that will allow monitoring of risks, thereby these measures will help reduce the loss of financial stability and ensure the long-term development of the economy of the region.

scholarly journals Effect of Long-Term Soil Management Practices on Tree Growth, Yield and Soil Biodiversity in a High-Density Olive Agro-Ecosystem

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1036
Author(s):  
Sauro Simoni ◽  
Giovanni Caruso ◽  
Nadia Vignozzi ◽  
Riccardo Gucci ◽  
Giuseppe Valboa ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Structure ◽  
Soil Management ◽  
Carbon Pools ◽  
Grass Cover ◽  
Soil Biodiversity ◽  
Canopy Effect ◽  
Soil Organic Carbon Pools

Edaphic arthropod communities provide valuable information about the prevailing status of soil quality to improve the functionality and long-term sustainability of soil management. The study aimed at evaluating the effect of plant and grass cover on the functional biodiversity and soil characteristics in a mature olive orchard (Olea europaea L.) managed for ten years by two conservation soil managements: natural grass cover (NC) and conservation tillage (CT). The trees under CT grew and yielded more than those under NC during the period of increasing yields (years 4–7) but not when they reached full production. Soil management did not affect the tree root density. Collecting samples underneath the canopy (UC) and in the inter-row space (IR), the edaphic environment was characterized by soil structure, hydrological properties, the concentration and storage of soil organic carbon pools and the distribution of microarthropod communities. The soil organic carbon pools (total and humified) were negatively affected by minimum tillage in IR, but not UC, without a loss in fruit and oil yield. The assemblages of microarthropods benefited, firstly, from the grass cover, secondly, from the canopy effect, and thirdly, from a soil structure ensuring a high air capacity and water storage. Feeding functional groups—hemiedaphic macrosaprophages, polyphages and predators—resulted in selecting the ecotonal microenvironment between the surface and edaphic habitat.

scholarly journals Towards a hydrological classification of European soils: preliminary test of its predictive power for the base flow index using river discharge data

2007 ◽  
Vol 11 (4) ◽  
pp. 1501-1513 ◽  
Author(s):  
M. K. Schneider ◽  
F. Brunner ◽  
J. M. Hollis ◽  
C. Stamm
Keyword(s):  
Water Movement ◽  
Base Flow ◽  
Regression Coefficients ◽  
Northern Europe ◽  
Flow Index ◽  
Discharge Data ◽  
Base Flow Index ◽  
The Uk

Abstract. Predicting discharge in ungauged catchments or contaminant movement through soil requires knowledge of the distribution and spatial heterogeneity of hydrological soil properties. Because hydrological soil information is not available at a European scale, we reclassified the Soil Geographical Database of Europe (SGDBE) at 1:1 million in a hydrological manner by adopting the Hydrology Of Soil Types (HOST) system developed in the UK. The HOST classification describes dominant pathways of water movement through soil and was related to the base flow index (BFI) of a catchment (the long-term proportion of base flow on total stream flow). In the original UK study, a linear regression of the coverage of HOST classes in a catchment explained 79% of BFI variability. We found that a hydrological soil classification can be built based on the information present in the SGDBE. The reclassified SGDBE and the regression coefficients from the original UK study were used to predict BFIs for 103 catchments spread throughout Europe. The predicted BFI explained around 65% of the variability in measured BFI in catchments in Northern Europe, but the explained variance decreased from North to South. We therefore estimated new regression coefficients from the European discharge data and found that these were qualitatively similar to the original estimates from the UK. This suggests little variation across Europe in the hydrological effect of particular HOST classes, but decreasing influence of soil on BFI towards Southern Europe. Our preliminary study showed that pedological information is useful for characterising soil hydrology within Europe and the long-term discharge regime of catchments in Northern Europe. Based on these results, we draft a roadmap for a refined hydrological classification of European soils.

Combined Genotypes of CCR5, CCR2, SDF1, and HLA Genes Can Predict the Long-Term Nonprogressor Status in Human Immunodeficiency Virus-1–Infected Individuals

Blood ◽  
1999 ◽  
Vol 93 (3) ◽  
pp. 936-941 ◽  
Author(s):  
Magdalena Magierowska ◽  
Ioannis Theodorou ◽  
Patrice Debré ◽  
Françoise Sanson ◽  
Brigitte Autran ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Chemokine Receptor ◽  
Multivariate Logistic Regression Model ◽  
Hla B27 ◽  
Hla Alleles ◽  
Immunodeficiency Virus ◽  
Combined Genotypes ◽  
Hiv 1

Abstract Human immunodeficiency virus (HIV)-1–infected long-term nonprogressors (LT-NP) represent less than 5% of HIV-1–infected patients. In this work, we tried to understand whether combined genotypes of CCR5-▵32, CCR2-64I, SDF1-3′A and HLA alleles can predict the LT-NP status. Among the chemokine receptor genotypes, only the frequency of the CCR5-▵32 allele was significantly higher in LT-NP compared with the group of standard progressors. The predominant HLA alleles in LT-NP were HLA-A3, HLA-B14, HLA-B17, HLA-B27, HLA-DR6, and HLA-DR7. A combination of both HLA and chemokine receptor genotypes integrated in a multivariate logistic regression model showed that if a subject is heterozygous for CCR5-▵32 and homozygous for SDF1 wild type, his odds of being LT-NP are increased by 16-fold, by 47-fold when a HLA-B27 allele is present with HLA-DR6 absent, and by 47-fold also if at least three of the following alleles are present: HLA-A3, HLA-B14, HLA-B17, HLA-DR7. This model allowed a correct classification of 70% of LT-NPs and 81% of progressors, suggesting that the host’s genetic background plays an important role in the evolution of HIV-1. The chemokine receptor and chemokine genes along with the HLA genotype can serve as predictors of HIV-1 outcome for classification of HIV-1–infected subjects as LT-NPs or progressors.

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