Features Fertilizer Seed & Chemical
June is time to reassess crop nitrogen needs

By Ken Panchuk, PAg, Provincial Specialist Soils

Early June is a good time to reassess your crop nitrogen needs. Generally, nutrient recommendations based on soil testing are adequate for most growing seasons but there are times when a top-up of nitrogen may be needed:

• If growing season conditions have improved since seeding and the crop is in need of more nitrogen to achieve the potential realistic target yield and/or protein level, then top-up nitrogen may be required.
• If higher than normal losses of nitrogen applied last fall or this spring are suspected, and/or the crop is starting to show symptoms of nitrogen deficiency, a top-up may be required.

Reviewing the soil test information, tissue testing, field scouting for nitrogen deficiency symptoms and a handheld Greenseeker may be used to compare areas within a field to aid in determining whether more nitrogen is needed. Also, get additional help, if needed, from your area agronomist or Agrologist.

The most common symptoms of nitrogen deficiency are the yellowing of the older leaves and/or pale green leaves, but keep in mind there are other causes of these symptoms.

Earlier application of top-up nitrogen helps recover yield better than applications made at later crop stages. The rate of nitrogen needs to be high enough to increase yield or protein. Also, keep an eye on the long-term weather forecast to help determine if top-up nitrogen will be effective.

Liquid nitrogen has the best fit for in-crop dribble banding using drop tubes or split nozzles. If rainfall is not expected shortly after application, then consider using a urease inhibitor that helps reduce volatilization loss while waiting for a rain to move the nitrogen into the soil.

June 9, 2015  By Saskatchewan Agriculture