Corn
Scheduling split nitrogen applications on corn?
Split application of nitrogen fertilizer may substantially improve corn nitrogen use efficiency, particularly during wet growing seasons. Corn extracts less than 15% of its seasonal nitrogen uptake before rapid vegetative growth begins. Maximum nitrogen use rate occurs just prior to pollination.
During early growth stages, considerable nitrogen may be lost due to denitrification and leaching, particularly if wet conditions persist. Therefore, the bulk of a split nitrogen application should be delayed until just prior to rapid vegetative growth. This growth period begins at the V10 growth stage (10th leaf stage) which occurs about 40 days after plant emergence or when plants are about 30 inches tall.
The normal nitrogen recommendation specifies applying 1/4 - 1/3 of the total N recommendation at planting with the bulk of the split application delayed until the V5-V8 growth stages (5-8 emerged leaves with collars present), which normally occur about 25-35 days after emergence.
