Impact of foliar fertilization with nanosized zinc hydroxy nitrate on maize yield and quality

Abstract

The objective of this study was to investigate the impact of foliar zinc application in the form of zinc hydroxy nitrate suspensions on maize grain yield and quality and on zinc distribution in the plant organs. The preparation of the zinc hydroxide nitrate (Zn5(OH)8(NO3)2·2H2O) was performed by pouring a NaOH solution into Zn(NO3)2·6H2O under vigorous stirring. All samples were characterized in detail by X-ray diffraction, scanning electron microscopy, thermal analysis, and inductively coupled plasma (ICP) mass spectrometry to determine their content, morphology and physicochemical properties. The field experiment was conducted at the Research Farm, Agricultural University, Bulgaria, via a randomized block design with eight variants in 3 replications. A significant (p < 0.05) effect on Zn accumulation in the maize stems and leaves by foliar zinc application during the first growth stage was found. The accumulation of zinc was followed by its remobilization from the stems to other plant organs during the second growth stage. It was concluded that the synthesized zinc hydroxy nitrate has potential as a long-term foliar fertilizer. Ensuring the optimal concentration of Zn at different times during the vegetative period lead to a substantial increase in the grain yield along with an improvement in the quality of the corn grain for all variants compared to those of the control.