Why planting in warmer soil is worth the wait

After a long, stubborn winter, Ontario farmers are anxiously planning to seed, and asking – do I plant corn and soybeans early and take advantage of potential yield gains, or do I wait for the ground to warm up to make sure my seed germinates?

Agronomist Dale Cowan has some advice: Do both.

“Wait for the soil to warm, then plant as soon as possible if the forecast is favourable,” says Cowan, senior agronomist at the AGRIS and Wanstead Coops. “A lot of people are worried that because of the cold weather, we’re now on schedule for late planting, but technically, we’re not late. We’ve had no usable heat, and the soil temperature is too low yet for planting, so although the weather has been cold, we’re not late.”

Warm seedbed is necessary

A warm seedbed is needed for corn and soybeans. They’re called base 10 crops, meaning they need soil temperatures of at least 10C and rising for best germination.

If soil cools off after seed is sown, germination slows and disease and insects can wreak havoc on development. So producers must keep an eye on forecasts, and manage accordingly.

“If the soil temperature gets to 10C but the forecast calls for a drop in the air temperature for several days, the soil will cool and germination may be a problem,” Cowan says.