SOLUBILITY OF FE, MN, CU and ZN FERTILIZERS AS A FUNCTION OF THE SUBSTRATE TYPE IN A DRIP IRRIGATION SYSTEM

Knowledge about micronutrient supply to vegetables under protected cultivation is very scarce.
Eight micronutrient fertilizers were allowed to react with six substrates (peat, treated peat, peat+CaCO₃, soil-1, soil-2 and sand) used in drip irrigation in Spain.
Solubility of Fe, Mn, Cu and Zn as a function of type of chelating agent (EDTA, EDDHA, DTPA and Polyflavonoid) and of culture substrate used was studied.

Fe added as fertilizers containing Fe-EDTA lost solubility by 35–55% in both soils which are high in CaCO₃ but remained mostly in solution with sand, peat and treated peat.
For peat+CaCO₃ results showed wider variations.
Fe-EDDHA remained soluble after having been shaken with both soils but showed a decreased solubility in peat, peat-CaCO₃ and treated peat.
Soluble Fe from Fe-polyflavonoid was significant only for soil-2.

Mn solubility decreased strongly for all chelates and substrates used and practically disappeared in peat treatments.

Cu and Zn remained in solution with both soils, showed increased solubility with peat-CaCO₃ and treated peat and decreased solubility with peat, except for Zn-DTPA.

Symposium on the Fertilization of Vegetables under Protected Cultivation

C. Cadahía, P. García, J.J. Lucena, M.J. Sarro, A. Gárate

https://doi.org/10.17660/ActaHortic.1988.222.21