By Alberta Agriculture and Rural Development
Sept. 9, 2014 - Once the decision to grow winter wheat has been made, one question that frequently comes up is when to fertilize.
"Traditionally, winter wheat has been seeded with very little fertilizer and then fertilized in the spring," says Doon Pauly, agronomy research scientist, Alberta Agriculture and Rural Development, Lethbridge. "Sometimes, however, producers get caught with not enough time in the spring to fertilize, or things get delayed, and yield is sacrificed."
Pauly says research has shown that fertilizing at seeding can be very effective.
"If you're banding your fertilizer away from the seed, in a lot of cases you can put down your entire crop's fertilizer requirement at the time of seeding. However, people can be a little reluctant to do that as it's a big investment and there is the potential that what isn't taken up in the fall can be lost over the winter."
To balance that potential loss, Pauly says producers can either put down some of the fertilizer at seeding and top it up with a surface application in the spring, or can use a blend of regular urea with ESN fertilizer. "This second option gives some immediate nitrogen from the urea while having a portion protected in the ESN form."
In many areas of the winter wheat growing areas of the province, the risk of overwintering nitrogen loss is quite low, says Pauly. "In southern Alberta, where most of the winter wheat is grown, we don't typically have big snowmelt events in the spring that give us saturated soil conditions that lead to denitrification. It's not to say it won't ever happen, but it is more unlikely to occur in the south than it is in other parts of the province."
Pauly says his recommendation is to put down at least half of the nitrogen in the fall so the crop gets off to a good start. "That way, if you are delayed getting fertilizer on in the spring, you haven't sacrificed yield. In many cases, you can benefit by putting even more than half down in the fall - it just depends on your comfort level with potentially having some loss. "