Effects of Liquid Urea Application Frequency on the Growth and Grain Yield of Corn (Zea mays L.)

Efficient nitrogen (N) management is considered one of the most important strategies for increasing sustainable crop yield along with maximizing nitrogen use efficiency (NUE). The aim of the study was to evaluate the effects of liquid urea (LU) application frequency on the growth, yield, and NUE of grain corn (Zea mays L.). The application frequencies urea were two split (2S) applied equally at 10 and 28 days after sowing (DAS), three split (3S) applied equally at 10, 40, and 65 DAS, and four split (4S) applied equally at 10, 30, 50, and 70 DAS organized by following randomized completely block design with four replicates. Results showed that stem diameter, ear length, fresh and dry stover weight, fresh cob weight, husk weight, kernel row/cob, and grain yield were higher in the LU treatments than granular urea (GU). Among all the treatments, the grain corn receiving LU3S had the highest stem diameter (2.03 cm), cob weight (248.25 g), 100 grain weight (29.08 g), N uptake (133.96 kg/ha), and NUE (72.84%). The corn grain yield of LU3S was 6.77 t/ha compared to the GU2S, which was only 4.95 t/ha. The N uptake along with NUE was significantly higher in LU3S treatment than other treatments. The results of this study suggest that the yield and NUE of corn were significantly affected by the urea source and application frequency of LU while LU3S was the most efficient treatment for maximizing the growth and yield of grain corn grown in tropical soil.