Determination of iron critical level for main agricultural soils cultivated with wheat (Triticum aestivum L.) in Sulaimani.

The factorial pot experiment was conducted at Bakrajo Research Station,Ministry of Agriculture and Water Resources, Sulaimani Governorate during thewinter growing season from 1/12/2014 to 10/6/2015 for limiting of Fe criticallevel of soils and wheat plant. The pot factorial experiment included the effectof five levels of Fe- EDDHA (0, 2, 4, 6, and 8) mg Fe kg soil-1 , soils of 20locations and their effects on growth, yield and quality of wheat usingcompletely randomized design with 4 replicates. The results indicated to thesignificant effect of applied Fe levels on grain yield of wheat, the highest meanvalue (12.66) g pot-1 was recorded from the second treatment (2 mg Fe kg -1) which ranged between (3.11-28.02) g pot-1 , while the lowest mean value (11.09) g pot-1obtained from the 5 th treatment (8 mg Fe kg -1 ) which ranged between (3.14-27.62) g pot-1 . The critical level of Fe was determined in wheat usinggraphic method and statistical method depending on iron concentration in theplant (mg kg-1 dry weight) and relative yield the iron which was (50.50 mg kg-1dry matter .While the critical level of iron in the studied soil was (2.61) mgkg-1using graphical method and (2.50) mgkg-1 depending on statistical method for the studied soils in Sulaimani governorate.