Effect of traditional sources of Zn and ZnO-nano-particles foliar application on productivity and P-uptake of maize plants grown on sandy and clay loam soils

Abstract

Zinc is an important nutrient for maize growth and productivity; yet, its availability in many soils seemed to be low. Appling Zn as soil fertilizers might not be the optimum solution to satisfy plant needs for this nutrient because Zn precipitates in presence of phosphate fertilizers. Alternatively, deficit of this nutrient may be amended through foliar application. Specifically, we hypothesized that the effect of Zn foliar application is quite enough to overcome Zn deficiency beside of its synergetic effect on P uptake. To test this hypothesis, a field study was conducted in a split-plot design where Zn-sources i.e. ZnSO4, Zn-EDTA and ZnO-nano-particles (ZnO-NP) were plotted in main plots while their rates of application (0, 5, 10 and 15 mg L-1) were schemed in sub-plots. Results obtained herein indicate that these three fertilizers not only improved significantly concentrations of both P and Zn in maize during V14-fouteenth leaf and physiological maturity growth stages but also increased significantly the available contents of these nutrients in soil, especially with increasing the level of foliar application. Moreover, these fertilizers improved significantly plant height during the above-mentioned growth stages and raised grain yield and 100-grain weight. The efficiency of these fertilizers could be arranged as follows: ZnO-NP> Zn-EDTA> ZnSO4. In conclusion, Zn foliar application especially in the nano form recorded a synergic effect on P availability and uptake; consequently these applications increased maize production with as just mentioned witht superiority for ZnO-NP; however, further studies are needed to investigate the residual effects of these nano-particles.