What is in this article?:
- No need for a fall application if wheat was planted following a failed corn or grain sorghum crop.
- Cannot expect to be successful with this approach most years.
- Nitrogen loss through denitrification and surface runoff are factors.
Last fall, area wheat growers began asking about applying nitrogen to their wheat crop this year. Our general recommendation at that time was that we did not see a need for a fall application if the wheat was planted following a failed corn or grain sorghum crop. We deduced that the short corn and grain sorghum crops likely had enough nitrogen left in the soil to supply the needs of the fall-planted wheat crop.
Observations over the fall and early winter have generally confirmed our theory to be correct.
We got by this year, but we cannot expect to be successful with this approach most years. Wheat planted behind a productive corn or grain sorghum crop will usually benefit from fall or early winter nitrogen application to “rot the stalks.” Microbial breakdown of the residue will often tie up soil nitrogen, making it unavailable to the wheat crop for a prolonged period.