The Fe-chelate suitable for application to crops grown on calcareous soils is

Fe-EDDHA is the Fe-chelate suitable for application to crops grown on calcareous soils. This chelated iron helps in correcting iron deficiency in flowers, vegetables, shrubs, and trees.
EDDHA is a chelate that protects nutrients against precipitation in a wide pH range of 4 - 9. And the availability of iron to plants is reduced through preci[piatation of iron at high pH, or by high concentrations of phosphorus.