%0 Journal Article
%T Physicochemical Properties and Surface Charge Characteristics of Arid Soils in Southeastern Iran
%A A. H. Moghimi
%A J. Hamdan
%A J. Shamshuddin
%A A. W. Samsuri
%A A. Abtahi
%J Applied and Environmental Soil Science
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/252861
%X The majority of previous studies on surface charge characteristics were done on tropical and subtropical soils. Information of such studies in the arid regions is limited. A study was conducted to investigate the relation between soil chemical and mineralogical properties and surface charge characteristics of an arid region in Southeastern Iran. Eight soil pedons, representing the alluvial and the colluvial deposits, were described, and their mineralogical and physicochemical properties were examined. The common clay minerals in the studied area are smectite, palygorskite, kaolinite, chlorite, and illite. The point of zero charge ( ) values are low (2.85¨C3.35) in all soils mostly affected by organic carbon (OC) and free iron oxide ( ). has a significant negative correlation with pH under field conditions ( , ). The point of zero net charge (PZNC) levels for all the soils were <2, due to the excess negative charge in these soils. The estimated PZNC values were less than in all soils because of the high permanent negative charge in these soils. The permanent negative charge ( ) of the soils studied is high and it has a significant positive correlation with pH, CEC, Na, Mg, SAR, clay content, palygorskite, OC, and . 1. Introduction Soil surface charges affect the chemical properties of soil by varying the quantity of electric and surface charge density. Surface charge properties have an important bearing on the migration of ions in soil, the formation of organomineral complexes, soil structure, plant nutrition, and the dispersion, flocculation, swelling, and shrinkage of the soil fractions [1]. Based on differences in the surface properties, soils can be classified into two basic categories: permanent-charge soils and variable-charge soils [2, 3]. Point of zero charge (PZC) often denoted as pH0 is one of the most important parameters used to describe variable-charge surfaces [4]. Uehara and Gillman [5] indicated that pH0 is the pH where the amounts of negative and positive charge of variable charge components where these are equal. The pH0 value for the temperate region of Iran was reported in the range of about 2.6 to 3.75 [6]. Anda et al. [7] reported that the pH0 of three Oxisols in Malaysia was about 3.9 to 5.7. The previous studies showed that the pH0 values decrease with increasing organic matter content and increase with increase in sesquioxides [6¨C8]. Taubaso et al. [9] reported that the pH0 values of Argentinean provinces soils were smaller than the pH in water, indicating that these soils had negative charge under natural conditions.
%U http://www.hindawi.com/journals/aess/2013/252861/