Influence of High-application of Zinc Fertilizers on Absorption and Accumulation of Zn Content and Maize Yield

Field experiment studied that the absorption and accumulation of Zn content and maize yield were influenced by an artificial increase of application of Zn fertilizer(50,100,150 kg/hm2 ZnSO4??7H2O)based on normal application of Zn fertilizer(10 kg/hm2,25 kg/hm2,ZnSO4??7H2O).The results showed Zn content of maize plants and grains had a significant increasing trend within the range 10~150 kg/hm2 during seedling stage,jointing stage,heading stage,filling stage and maturity period.There was a significant positive correlation between the application of Zn fertilizer and Zn content.And the accumulated Zn content increased with the growth of plants with the same application of Zn fertilizer,which indicated that maize had an increasing absorption of Zn from the soil at different growth stages.Overall,Zn uptake rate increased with the increase of application of Zn fertilizer on the ground part of maize at each growth stage,with the maximum of Zn uptake rate in the jointing stage and heading stage.The maize yield increased thanks to the increase of Zn application,but reduction was still visible due to excessive application of Zn fertilizer.The optimal application was 50 kg/hm2.However,maize with high-applied Zn fertilizer had better yield and Zn content of grain and plants than that with normal application of Zn fertilizer.