The Nature of Iron Oxide Distribution in Some Calcareous and Gypsiferous Soils

The study area is located within two regions. first site in Tikrit city (Tikrit University) represents gypsiferous soils and the second calcareous Erbil Governorate. Two pedons were chosen P1 (rainfed) P2 (cultivated), other P3 P4 ( cultivated) . showed presence of gypsum crystals spindle lenticular type with a length ranging between (0.2 -0.5) mm , pores vughs chamber, while dominance planer interconnected chamber pedons. Iron oxides appeared different forms single discrete particles or Ferriargillans cutan especially Erbil's pedons, values ​​of iron varied, as total, free ,and amorphous ranged (8.77 -12.81), (8.17 - 10.30), (6.82 9.19) g.kg-1, respectively, compared themselves for which (2.98 5.39), (2.45 4.86), (1.19 2.67) respectively. While oxide ​​showed an increasing their ​​in (1.26 2.19) g. kg -1 (1.01 – 1.81) -1.