Rice growth improvement, bio-fortification, and mitigation of macronutrient requirements through foliar application of zinc and iron- glycine chelate and zinc sulfate

Foliar application of Zinc (Zn) and Iron (Fe) fertilizers is known to be an effective solution to enhance rice grain yield and bio-fortification. The objectives of the current field experiment were to evaluate the effects of the foliar application of 0.5, 1, and 1.5 kg ha(-1) of Zn and Fe glycine amino acid chelates and ZnSO4 on rice grain yield, protein, Zn, and Fe content of head rice (Hashemi cultivar) under both in the recommended and 1/2 of the recommended dose of NPK. The highest increase in the grain yield was recorded at 0.5 kgha(-1) Fe-glycine amino acid chelate by about 29.2%. The maximum increase in protein and Zn content of head rice were recorded at 1.5 kg ha(-1) of glycine amino acid-Zn chelate by about 10.5 and 22.3%, respectively. The most effective treatment to enhance the Fe content of head rice was the foliar application of 1.5 kg ha(-1) of glycine amino acid-Fe chelate by about 32.6%. Interestingly, the foliar application of 1 kg ha(-1) Zn-glycine amino acid chelate plus 1 kg ha(-1) Fe-glycine amino acid chelate at the plots that received 1/2 of recommended NPK increased the grain yield, and protein, Zn and Fe content of head rice compared to control by about 7%, 18.5, 7.5, and 26.2, respectively. Therefore, regardless of rates and types, foliar application of Zn and/or Fe could enhance both rice yield, protein, Zn, and Fe content of head rice both in plots that received recommended and 1/2 of the recommended dose of NPK.