Document Type : Original Article


Halabja Technical College of Applied Science Halabje Zamaqi



In the calcareous soils, iron solubility is very limited due to high pH value and high calcium carbonate content. In this study, the solubility and partition coefficient of Iron in the range of vegetable grown calcareous soils from Sulaymaniyah province, Iraqi Kurdistan were studied. The aim of this study was to determine the Fe mineral that controls the solubility of Fe and range of Fe adsorbing in these soils. A total of 21 soil samples were incubated for 56 days and periodically at (1, 7, 14, 28, and 56) the soluble Fe was determined. The results indicate that the solubility of Fe in the studied soils were saturated with respect to siderite in all the studied soils and incubation period with slight fluctuation. Soluble Fe is negatively correlated with total Fe in soil and pH values but highly correlated with DOC and TDC. Also, a low range of Log Kd values from 0.11±0.04 to 1.90±0.03 for Fe was recorded indicating low adsorption capacity for Fe by soils due to the presence of a high amount of organic matter in the studied soils. High correlation was found between Log Kd values with DOC and TIC in all soils. From the results it is concluded that siderite is dominant Fe minerals in Iraqi Kurdistan calcareous soils and soil organic matter has the main role in increasing Fe availability.


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