Water requirements of forage corn on Canadian prairies

The water requirements of forage corn on the Canadian prairies are among the highest of all annual crops, with total seasonal needs typically ranging from 500 to 550 mm (20–22 inches) of water during the growing season under optimal conditions.wcds.ualberta+2

Peak Demand Periods

• Peak water use occurs from tasseling through silking and fruit formation, usually in late July to early August, when daily demand can reach 7–9 mm per day.albertafarmexpress+2

• Water use declines to 2–3 mm per day during ripening prior to harvest.open.alberta+1

Soil Moisture and Rooting

• Over 70% of the extracted water comes from the upper 50 cm of a 1-meter root zone, even though roots can extend to this full depth at peak vegetative stages.producer+2

• Maintain available soil moisture above 60% in the top half of the root zone during emergence, vegetative, silking, and grain-fill stages to maximize yield and forage quality.topcropmanager+2

Irrigation and Water Management

• Given that average prairie rainfall is lower than required, irrigation is essential for high-yield forage corn, especially in southern Alberta and Saskatchewan.agric.gov+1

• Light, frequent irrigations (e.g., 15–30 mm per application) are preferred over heavy, infrequent ones to avoid water stress and to keep soil moisture relatively even.albertafarmexpress+2

• Terminate irrigation about 2–3 weeks before the anticipated silage harvest to allow crops to finish maturing while avoiding overly wet soil at harvest.topcropmanager

Practical Recommendations

• Seasonal water needs: 500–550 mm (20–22 inches) per season.wcds.ualberta+2

• Peak daily use: 7–9 mm/day (tasseling to early grain fill).prideseed+1

• Critical stages: Tasseling, silking, and early cob/ear development—dry conditions at these times sharply reduce yield.prideseed+1

Meeting these water needs through both rainfall and irrigation is crucial to realize the full yield and quality potential of forage corn on the Canadian prairies.agric.gov+3

1. https://wcds.ualberta.ca/wcds/wp-content/uploads/sites/57/2018/05/p-147-162-Beauchemin-WCDS-2018-Producing-High-Quality-Corn-SIlage.pdf
2. https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/bus15031/$file/potential-for-grain-corn-sm.pdf?OpenElement
3. https://www.albertafarmexpress.ca/crops/timing-is-key-when-irrigating-silage-corn-crops/
4. https://prideseed.com/fieldtalk/corn-water-use---western-canada
5. https://open.alberta.ca/dataset/f0ccbf6f-b6fe-40f2-ae64-e2f37f1c6148/resource/d059293e-754a-4296-9aec-a4882de29717/download/2016-08-agrifacts-agdex-111-561-1.pdf
6. https://www.producer.com/video/sufficient-soil-moisture-essential-for-corn/
7. https://www.topcropmanager.com/tips-for-new-growers-of-irrigated-corn-19756/
8. https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/ba3468a2a8681f69872569d60073fde1/42131e74693dcd01872572df00629626/$file/irrsalin.pdf
9. https://publications.gc.ca/collections/collection_2024/aac-aafc/A59-94-2024-eng.pdf
10. https://rapp.ualberta.ca/wp-content/uploads/sites/57/wcds_archive/Archive/2007/Manuscripts/Jane.pdf