The Use of Polymer-Coated Urea in North Florida Field Corn Production

Field corn is an important crop grown in the Suwannee Valley region of North Florida. Field corn requires high nitrogen inputs to obtain optimal yields compared to other row crops commonly grown in the region, such as peanuts and cotton. Basin management action plans (BMAPs) have been implemented in this region to reduce the leaching and runoff of nutrients, such as nitrogen, into local bodies of water. In this experiment, an on-farm trial was conducted comparing the use of polymer-coated urea as a controlled-release fertilizer (CRF) to split applications of conventional fertilizer. Plant tissue and soil samples, collected at 0–15, 15–30, 30–60, and 60–90 cm depths, were sampled approximately every two weeks throughout the growing season. The study found that CRF treatment had no significant impact on corn yield, moisture content, soil nitrate concentrations below the root zone, or plant tissue nitrogen concentrations in both the 2021 and 2022 seasons. However, contrast results did reveal significant differences between treatments at specific depths and sampling dates. The conclusion of this study is that CRF treatment did not improve yield or tissue nitrogen content compared to split applications of conventional fertilizers. The maize weevil (Sitophilus zeamais), a major corn insect pest, likely contributed to the observed lower yields.