Nitrogen Fertilization Considerations for High-Yielding Winter Wheat In the South Central Piedmont of North Carolina

Abstract

Nitrogen management in the production of winter wheat are important for both yield and quality. Application timing and rate are critical for winter wheat production fields with high yield potential. An on-farm, randomized trial, was conducted in Unionville, North Carolina, to investigate the correlation between N fertilization rates, yield, and plant lodging. Winter wheat was evaluated at rates of 100, 125, 150, and 175 lbs N/ac during the second (early Spring, GS-25) and topdress (GS-30) application for each treatment. Tissue samples were collected at GS-30 and analyzed for NO3 -N concentration. Plant height, head length, and spikelet count were measured at GS-85 (soft dough) and no significant differences were found. Means were 40.6 inches, 4.7 inches, and 25.2 spikelets, respectively. However, significant differences in yield were observed between the 100 lbs/ac and 150 lbs/ac application rates. Means were 90.8 bu/ac and 67.7 bu/ac, respectively. Significant differences were also observed in percent lodging between all treatments except for 100 lbs/ac, 150 lbs/ac, and 175 lbs/ac. Means were 25%, 30%, and 95% for percent lodging, respectively. Results indicated a moderately positive correlation between increasing N fertilization rates and percent lodging. These findings reinforce the relationship between N fertilization and winter wheat lodging.