Effects of Organic and Inorganic Zinc Sources on Maize Plant Growth, Zn and P Uptake Efficiency Under Different Phosphorus Environments

This study was conducted to determine the zinc (Zn) and phosphorus (P) content, removed quantities and intake activities of the corn plant of organic and inorganic form zinc sources applied in different amounts of phosphorus. The experiment was established in greenhouse conditions in a soil with slightly alkaline reaction, calcareous, low organic matter and phosphorus content in three replicates according to the coincidence plots experimental design. In the experiment, zinc was applied at 6 mg Zn kg-1 using inorganic (ZnSO4.7H2O, ZnO and 20-20+Zn) and organic (Zn-Gluconate, ZnSO4.7H2O+K-Humate and ZnSO4.7H2O+Aminoacid, Zn-EDTA) sources and phosphorus was applied at 0 and 120 mg P kg-1 using DAP. As a result of the study, it was determined that dry matter content, P and Zn content, P and Zn uptake, P and Zn reuptake efficiency of maize varied depending on organic and inorganic zinc sources in case of low and high phosphorus content in the soil. In cases where the phosphorus content in the soil is low, the highest dry matter amount, P content and removed P amount of maize were obtained with the application of inorganic form 20-20+Zn, while the Zn content and the amount of Zn removed were obtained with the application of organic form Zn EDTA. In case of high phosphorus content in the soil, the highest dry matter content, P and Zn contents and P and Zn removal amounts of maize were obtained with organic sources containing Zn. Phosphorus reuptake efficiency differed according to zinc application sources and the amount of phosphorus applied, and it decreased by 11% with inorganic form 20-20+Zn application and increased by 38% with organic form Zn Gluconate application compared to inorganic form ZnSO4.7H2O application (17.9%), which is widely used in the elimination of zinc deficiency. Zinc reuptake efficiency decreased by 33% with the application of 20-20+Zn with inorganic form compared to the application of ZnSO4.7H2O with inorganic form (5.4%), while it increased by 17% with the application of organic form Zn Gluconate. The uptake efficiency of plant phosphorus and zinc was 21.0% and 5.1%, respectively, and the highest was determined with organic form Zn Gluconate application. In terms of dry matter content and P and Zn uptake efficiency of maize plants, we can recommend the application of organic form Zn-Gluconate instead of the commonly used inorganic form ZnSO4.7H2O source.