Effects of Some local Conditions on Leaching Factor of Aridisols in Kalar/Garmian, Kurdistan- Iraq

Abstract

Five sites were selected in Kalar city on different topographic position. The mean annual rainfall of the study area about 280 mm with about 24.5 C° mean annual temperature. The study area used for rain feed crop production. Morphological properties of the studied pedons indicated that all pedons were developed with Ochric epipedons and Cambic and Argillic endopedons .The results of particle size distribution show a wide differences between sand and clay in surface horizons except pedon (2) because of low elevation compared with other pedons. Moreover, the results of exchangeable sodium and potassium indicate that pedons (4) and (5) had the lowest value of soil leaching factor which is an indication of the high activity of weathering and leaching processes. In another hand, the results of total element analysis has observed that the silicate ratio were high to indicate the high leaching processes which is the proof of the existence of fine materials movement particularly clay colloids, this is not merely due to the rare rainy weather conditions that are prevalent recently but is a result of wet paleoclimatic conditions, and this movement eventually occurred due to in situ factors. All soils are belonged to Aridisols order with suborders Argids and Cambidsas these soils are in aridic moisture regime include Ochric diagnostic surface horizon with Argillic and Cambic diagnostic subsurface horizons.