Pedogenical Distribution of some Micronutrients in Prevailing Sub Great Soil Group in Iraq

The study included the analysis of (341) samples from eight pedons cover most of the prevailing sub great soil groups in Iraq, which are (Typic Torrifluvents, Typic Torrients, Typic Gypsiorthids, Typic Calciorthids, Aquollic Salorthids, Typic Chromoxerects, Typic Xerrochrepts and Typic Calcixerects) to study the pedogenetic distribution of total and bioavailable content of the manganese, zinc, copper, and iron also its relationship with some soil properties. Results showed significant differences between the studied regions of total content of microelements, the bioavailability content also showed a significant deference between the studied regions. The physical and chemical soil properties clearly affected on their content of micronutrient and 77% of the studied samples were below the critical limit for zinc, but 65% of the studied samples were under the critical limit for iron. This refers to the response of the cultivated crops in such sub great soil groups to the addition of Zn and Fe fertilizers, also pedogenetic distribution of the content of these microelements showed a decrease with depth and compatible with the distribution of each of the separated clay and organic matter and decrease with the increase in the soil content of calcium carbonate.