Average corn seeding rates, yields increase
Average corn seeding rates used by growers in the U.S. and Canada have increased from 23,000 seeds per acre in 1985 to more than 30,000 seeds per acre today. That’s a steady move up during that period of almost 300 additional seeds per acre each year.
During that same time, U.S. yields increased from about 105 bushels to nearly 160 bushels per acre, a rise in yield of about 2 bushels per acre per year.
• Corn yields have steadily risen as have seeding rates.
• Better stress tolerance allows corn at higher populations.
• Early-maturity hybrids have a higher population optimum.
Pioneer’s extensive plant population trials indicate that corn seeding rates generating the most income range from 32,000 seeds per acre at yields of 150 to 170 bushels per acre, to 38,000 seeds per acre at yields exceeding 250 bushels per acre. The work also showed:
• Higher corn seeding rates accompanied by improved stress tolerance in hybrids has contributed to incremental yield gains.
• Acres planted at 33,000 seeds per acre or above now exceed 30% in North America as a whole, growing by nearly 15 percentage points in just the last three years.
• Early-maturity hybrids (less than 100 CRM, for comparative relative maturity) had a higher population optimum than later hybrids in Pioneer studies.
• Optimum plant population did not differ by row width (including twin rows) in most Pioneer and university studies.
• In general, growers should drop 5% more corn seeds than the target population to account for germination or seedling losses.
• Extreme environments, such as no-till and early planting, may require increasing seeding rates by 10% over target.
The observations strongly suggest that increased seed rates may have played a major role in corn yield increases over the last 25 years.
This article published in the January, 2012 edition of THE FARMER-STOCKMAN.