Typical irrigation schedule for wheat on Canadian prairies

The typical irrigation schedule for wheat on the Canadian prairies focuses on maintaining adequate soil moisture, especially during the most sensitive crop growth stages: heading and flowering. Spring wheat generally needs 420–480 mm (16–19 inches) of total water across the season, which includes both rainfall and irrigation input.agric.gov+2

Key Timing and Frequency

• Emergence to Vegetative Stage: Light, frequent irrigation is recommended, maintaining available soil moisture above 60–65% in the upper 50 cm of the root zone. Root depth expands from shallow at emergence to about 1 meter by flowering.mbcropalliance+1

• Heading and Flowering: This is the period of peak water demand, with wheat using up to 7 mm per day. Irrigation is critical to avoid water stress, as shortages here can cause flower abortion and reduced yield.agric.gov+1

• Grain Fill to Maturity: If moisture is sufficient earlier, the need for irrigation declines after flowering. Final irrigations (if necessary) can be applied at the soft dough stage; further watering is generally not needed beyond this point.agric.gov+1

Seasonal Water Management

• Target Available Moisture: Roughly 16–20 inches of total available moisture is needed for a typical 80-bushel yield, combining rainfall and irrigation. Many prairie regions receive only 8–12 inches of rain in a season, requiring irrigation to cover the deficit.antaraag+1

• Scheduling Strategy: Use soil moisture sensors or manual checks to monitor available water. Begin irrigating before depletion falls below 60–65% of available water in the upper root zone. Adjust frequency and amount based on rainfall, soil type, and wheat growth stage.publications+2

Practical Example (Southern Alberta)

• Water use: Up to 7 mm/day at flowering.

• Number of irrigations: Typically 4–8 applications, adjusted for rainfall and soil storage.

• Each irrigation: Apply enough water to refill the active root zone, generally 30–50 mm per event.agric.gov+1

Additional Considerations

• Root zone depth increases through the season; most extraction is from the upper 50 cm.

• Over-irrigation can promote disease, especially at flowering—avoid excessive canopy wetness.agric.gov

• Well-timed, moderate, frequent irrigation typically yields the best results for prairie wheat.antaraag+2

1. https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/ba3468a2a8681f69872569d60073fde1/fd89ad4f75f8525b8725786b004fa8d5/$FILE/112_561-2.pdf
2. https://www.antaraag.ca/agronomy/just-how-much-water-does-wheat-need/
3. https://mbcropalliance.ca/directory/production-resources/wheat-and-barley-crop-water-use/
4. https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/ba3468a2a8681f69872569d60073fde1/d6733cfae82fab738725785400504ee9/$FILE/112_561-1.pdf
5. https://publications.gc.ca/collections/collection_2024/aac-aafc/A59-94-2024-eng.pdf
6. https://irrigationsask.com/wp-content/uploads/2024/07/A59-87-2022-eng.pdf
7. https://www.sciencedirect.com/science/article/abs/pii/S0378377420321387
8. https://cris.iucc.ac.il/en/publications/optimal-irrigation-scheduling-for-wheat-production-in-the-canadia
9. https://open.alberta.ca/dataset/254a651b-7c09-4d35-8a86-d4214c15d1fb/resource/5c122199-77ea-45a0-a718-928c86a73890/download/5058307-2011-agri-facts-optimum-seeding-rates-irrigated-grain-oilseed-crops-100-561-2.pdf
10. https://cdnsciencepub.com/doi/10.4141/CJPS10103
11. https://cdnsciencepub.com/doi/10.4141/cjss2013-016