Soil Taxonomy (ST) and World Reference Base (WRB) Systems Proficiency to describe Saline and Gypsiferous Soils Properties in Some Region of East Azerbaijan

The soil management and optimum usage require a correct soil classification and detection of their main characteristics. So in this research work, the Soil Taxonomy and World Reference Base systems proficiency to qualify saline and gypsiferous soils properties and estimate of the relative amount of clay minerals with effect on soil characteristics are discussed. For this purpose, saline and gypsiferoussoils of two regions from east Azerbaijan (Dasht-e-Tabriz and Khaje) were selected and after soil profiles description, sampling of all horizons and layers were carried out. Then samples were prepaired and different experiments were conducted for the study of ST and WRB proficiency. In the majority of soil profiles, the presence of heavy textured lower horizons has caused excessive accumulation of salts in the surface and middle horizons and salic and gypsic horizons formations. In general, according to WRB and ST, soils of these regions are classified in three reference soil groups of solonchaks, solonetz and gypsisols and two suborders of salids and gypsids, respectively. Based on mineralogical results, the most common and abundant clay mineral in this soils were illite which could be used as a mineralogy class in family level of ST system. As a result, in this kind of soils, the WRB system by high explanation of soil properties and adding dominant clay minerals name in qualifiers can be superior to ST.