Search

New fertilization methods using low zinc (Zn) rates have been developed and marketed for rice (Oryza sativa L.) fertilization. Limited research is available to validate the efficacy of these methods. Our research objectives were to evaluate the effect of Zn seed treatment rate combined with six Zn fertilization methods on: 1) early-season canopy coverage, 2) rice seedling Zn concentration, and 3) grain yield. Two field experiments were conducted in 2017 on soils mapped as Calloway and Calhoun silt loams. 'Roy J' (Calloway) or 'Diamond' (Calhoun) rice was treated with 0 or 0.33 lb Zn/cwt (hundredweight) as ZnO and was combined with: i) no Zn (UTC), ii) granular ZnSO4 applied at 10 lb Zn/acre (GRAN), iii) 1.5 lb Zn/acre as McroEssentials (MESZ), iv) 1.0 lb Zn/acre as Zn-EDTA a (EDTA), and v/vi) 0.5 and 1.0 lb Zn/acre of WolfTrax Zn-DDP (DDP). On the Calhoun soil, canopy coverage was not affected by Zn seed treatment rate or fertilization method. When Zn fertilization methods were averaged, application of 0.33 lb Zn/cwt to seed increased seedling Zn concentration (P = 0.0044) by 3.3 ppm (mg Zn/kg) compared with rice seed that had no Zn seed treatment. A significant interaction between Zn seed treatment rate by fertilization method tended to have greater canopy coverage on the Calloway soil for rice fertilized with MESZ. Grain yield was not affected by Zn seed treatment rate, fertilization methods, or their interaction. Results suggest that low-use-rate Zn fertilizers provide only minimal Zn for rice seedlings, and should be avoided on fields where Zn deficiencies are probable. [ABSTRACT FROM AUTHOR]