Evaluation the efficiency of different application method of Fe aminochelates compared to FeSO4 on yield and quality traits of oleic Sunflower (Helianthus annuus L.) in a calcareous soil

Abstract

In modern and sustainable approaches, it is necessary to address the nutrient deficiencies that limit agriculture productions.­ Routine inorganic fertilizers such as FeCl2 and FeSO4, are not effective in correcting iron (Fe) deficiency due to their chemical nature and rapid conversion of soluble Fe forms into unavailable Fe (III)-oxide or hydroxide forms, particularly under lime conditions. Recently, organic complexing agents such as amino acids have been considered important due to increasing nutrient bioavailability in the soils as well as improving plant stress tolerance for more yield. It is hypothesized that the use of ecofriendly Fe (II)-amino acid chelates can increase Fe uptake by plant as such products have the potential to form relatively stable complexes with minerals as "aminochelates". Aminochelate fertilizers are the latest novelties regarding plant nutrition in agricultural production systems. Amino chelates provide higher bioavailability and absorption of micronutrients due to effective ingredients with no environmental side effects. Here, we investigate the effects of Fe aminochelates as Fe sources on the yield of sunflower (Helianthus annuus L.) plants in field condition. We made use of synthesized Fe (glycine)2 [Fe (Gly)2] and Fe (methionine)2 [Fe (Met)2] amino chelates for seed priming, fertigation and foliar application on plant leaves. This experiment showed that all methods of Fe aminochelates application, especially foliar feeding, can increase shoot iron content and improve nutritional quality of sunflower in Fe-deficient soils. We observed the higher effectiveness of Fe aminochelates compared to FeSO4 on increasing plant growth parameters, grain and oil yield, biomass production and activity of antioxidant enzymes. Overall, our results suggested that application of Fe aminochelates can be considered as an effective approach to overcome the plant Fe deficiency and improve the yield of plant in calcareous soil. Future experiments will investigate the effects of aminochelates on soil biological parameters and soil enzymes activity in rhizospheres using imaging techniques. Key words: Aminochelates; antioxidant enzymes; grain yield; iron deficiency; nutrient uptake