PH STABILITY OF FE-CHELATES IN SOILLESS CULTURE
Soilless cultures could not exist without the discovery that iron chelates can be used in nutrient solutions for delivering iron to the plant roots. The choice of the best iron chelate in soilless cultures is discussed by making use of a speciation calculation model. Fe-EDTA is often not stable enough and Fe-DTPA (or sometimes Fe-EDDHA or Fe-EDDHMA) is the product of choice. Also the need for chelation of Mn, Zn and Cu is discussed and what the influence is on the stability of the iron chelate, when the A- and B-tank solutions come together in the final nutrient solution. Also the consequences of a high Cu or Zn level (either chelated or not chelated) in the nutrient solution for the stability of the Fe-chelate will be shown. Both elevated levels of copper and zinc will result in lower concentrations of iron in the nutrient solution. Chelation of copper, zinc and manganese will result in a lower loss of iron.
Bugter, M.H.J.M. and Reichwein, A.M.A. (2007). PH STABILITY OF FE-CHELATES IN SOILLESS CULTURE. Acta Hortic. 742, 61-66
iron chelates, nutrient solutions, plant roots