Zinc Sulfate Coated Urea Fertilizer As a Potential Zinc Source in Drill-Seeded Delayed Flood Rice Production.

Nutrient-coated urea fertilizers have been developed primarily to reduce ammonia volatilization losses; however, they can potentially mitigate micronutrient deficiencies. The physical coating and bigger granule size of coated urea fertilizers can improve micronutrient distribution and uptake. A two-year field study was conducted to evaluate the effect zinc sulfate-coated urea (ZSCU) combined with starter application of ZnSO₄ on aboveground biomass, tissue Zn, Zn uptake, zinc recovery efficiency (ZRE), and grain yield in a drill-seeded, delayed flood rice production system. The field trial was established in a farmer’s field near Mamou, LA in 2014 and 2015. Ten Zn fertilizer treatments comprising of a split application of ZnSO₄ as starter and ZSCU as pre-flood Zn fertilizers were evaluated. There was a significant linear response to tissue Zn, Zn uptake, and Zn recovery efficiency in 2014. Linear regression analysis also showed that Zn uptake influence grain yield in 2014. During the 2014 growing season, the split application had similar grain yield, biomass, Zn uptake, and ZRE as the recommended practice of single application. There was no significant biomass and yield response to increasing application rate of Zn in 2014 and 2015. The findings of this study demonstrated that ZSCU fertilizers is a potential Zn source and may be useful in Zn deficient soils.