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Effect of Fe:ligand ratios on hydroponic conditions and calcareous soil in Solanum lycopersicum L. and Glycine max L. fertilized with heptagluconate and gluconate
Author(s) -
IslasValdez Samira,
LópezRayo Sandra,
Arcos Jessica,
Menéndez Nieves,
Lucena Juan J.
Publication year - 2020
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.10119
Subject(s) - calcareous , chemistry , ligand (biochemistry) , chelation , solanum , size exclusion chromatography , hydroponics , chlorosis , nuclear chemistry , glycine , inorganic chemistry , horticulture , botany , organic chemistry , biochemistry , biology , receptor , enzyme , amino acid
BACKGROUND The environmental risk from the application of synthetic chelates has led to the use of biodegradable complexes to correct Fe deficiency in plants. In this article, the Fe oxidation state, the Fe:ligand ratio, and the molecular weight distribution for heptagluconate (G7) and gluconate (G6) are considered as key factors for the efficacy of complexes as fertilizers. Complexes with different Fe:ligand ratios were prepared and analyzed by gel filtration chromatography (GFC). The ability of Fe:ligand ratios to provide Fe to tomato in hydroponics and soybean in calcareous soil was tested and compared with synthetic chelates (Fe 3+ :HBED and Fe 3+ :EDTA). RESULTS G7 presented greater capacity to complex both Fe(II) and Fe(III) than G6, but the Fe(II) complexes exhibited poor stability at pH 9 and oxidation in solution. Gel filtration chromatography demonstrated the polynuclear nature of the Fe 3+ :G7 at various ratios. The effectiveness of the Fe fertilizers depend on the Fe 3+ :ligand ratio and the ligand type, the Fe 3+ :G7 (1:1 and 1:2) being the most effective. Fe 3+ :G7 (1:1) also presented a better response for the uptake of other micronutrients. CONCLUSION Fe 3+ :G7 molar ratios have been shown to be critical for plant Fe uptake under hydroponic conditions and with calcareous soil. Thus, the Fe 3+ :G7 at equimolar ratio and 1:2 molar ratio can be an environmentally friendly alternative to less degradable synthetic chelates to correct Fe chlorosis in strategy I plants. © 2019 Society of Chemical Industry