Nitrogen fertilization with conventional and slow-release urea in two forms of application on maize

Urea is the nitrogen fertilizer most used in agriculture and the most subject to N losses. Thus, it is important to look for alternatives to reduce these losses and increase agronomic N use efficiency. In this sense, this study evaluates the effect of split or single application of slow-release and conventional urea in maize development and yield, as well as the fertilizer use efficiency by plants. The experiment was carried out in Santa Rosa do Sul - SC, in a randomized complete block design with 5 treatments and 3 replicates. The treatments evaluated were: con­trol; 100% of the recommended dose of conventional urea at sowing; 30% of the recommended dose of conven­tional urea at sowing and 70% at topdressing; 100% of the recommended dose of slow-release urea at sowing; 30% of the recommended dose of slow-release urea at sowing and 70% at topdressing. The variables analyzed were ear insertion height, stem diameter, leaf chlorophyll content (R1 stage), yield components, crop yield, and nitrogen use efficiency. The split application of slow-release urea to the soil positively affected stem diameter and nitrogen use efficiency in maize plants, being, therefore, a good fertilization alternative for the crop in the soil and climate conditions of the region.