Fundamentals of geology I. (lithosphere) 1 1. The formation of the Earth 1
Download 9 Mb.
|
Pict. 10.7. kép: Traces of wind erosion Pict. 10.8. Ripplemarks on sand surface (www.enfo.agt.bme.hu) (www.tapioszecso.blogspot.hu) 10.2.2. Secondary salinization Worldwide, the major factor in the development of saline soils is a lack of precipitation. Most naturally saline soils are found in (semi)arid regions and climates of the globe. Salinization has a direct effect on both plant growth and the structure of the soil. If the soil is saline a plant will have to expend energy bringing water into it's cells because it is forced to work against osmotic potential. The cation exchange complex (CEC) effects the stability of colloid size particles in the soil. The cation's positive charge will be attracted to the negative charge found on clay particles which make up most of the colloid fraction. Di-valiant cations (Ca, Mg) will allow the colloidal particle to get close enough together that Van Dehr Wahls forces will cause the clays to flocculate, or form stable aggregates. Sodic soils, whose CEC is dominated by mono-valiant sodium cations, will tend to be dispersed and not form stable aggregates. Sodium is mono-valiant and can not pull the colloid particles close enough together for the short range Van Dehr Wahls forces to act. Sodic soils will tend to have a dark, organic appearance due to the dispersion of clay and organic particles while saline soils will tend to have a white crusty surface due to the precipitation of salts. Both of these effects will lead to decreased permeability and hydraulic conductivity (Pict. 10.9.). 
Directory: tartalom -> tamop412A tamop412A -> Agricultural Economics II. Popp, József Agricultural Economics II tamop412A -> Ethology practical Vilmos Altbäcker Márta Gácsi András Kosztolányi Ákos Pogány Gabriella Lakatos tamop412A -> Operating Systems Lecture Notes Attila Dr. Adamkó Operating Systems Lecture Notes tamop412A -> Agroinformatics Herdon, Miklós Agroinformatics tamop412A -> Paternoster of Programmers Reloaded tamop412A -> Lőrincz, András Mészáros, Tamás Pataki, Béla Embedded Intelligent Systems tamop412A -> This course is realized as a part of the TÁmop 1 A/1-11/1-2011-0038 project tamop412A -> Computational biochemistry ferenc Bogár György Ferency Download 9 Mb. Share with your friends:
|