Iron fertilizers are grouped into three main classes: inorganic Fe compounds (soluble ones such as FeSO4•7H2O), synthetic Fe chelates [such as ethylenediamine tetraacetic acid (EDTA) and ethylenediamine-di(o-hydroxyphenylacetic acid) (EDDHA)] and natural Fe-complexes (humates and amino acids) (Abadía et al.,2011).