If you’re trying to keep a bag of seed from germinating before you plant it, the bag warns you to store it in a cool, dark place.
Understandably, producers can be pretty leery of planting into the cool dark of a seedbed when it’s cold out.
But are they too leery? A few agronomists weighed in during the Ontario Agriculture Conference last month.
Here’s the broad strokes: lighter soils work better for planting early. Soybeans emerge better than corn. High-stress-emergence-tolerant varieties handle cold planting better, as do lower-population varieties. Don’t plant early in fields without tile drainage. Don’t plant unless you’ve got a window of at least a couple days of warm-ish weather.
The agronomists also had some tips for fine-turning those cold-planting plans.
Chuck Belanger, of Maizex Seeds, noted that when it comes to corn, there’s consensus on planting temperature: at least 10 C. Soybeans were a bit sketchier, ranging from 10 C to going by the OMAFRA calendar date.
Growers planting soybeans early should ditch the drill as a cluster of beans all pushing together can get through even a three-inch thick crust. But planting cold, especially corn, is a risk. He showed a side-by-side of two fields: one planted May 8, the other June 22. The June 22 field outyielded it by 50 bu/ac.
Chris Olbach, a Pioneer agronomist for Eastern Ontario, did some pioneering experiments with cold-planted crops. He dumped 1,500 lb. of ice on some fields and watched how well they germinated. Germination varied significantly based on timing but massively based on variety. Ice dropped on the crop immediately cut germination down to 84 per cent for the stress-tolerant variety but down to 45 per cent for the control crop. Applying the ice just 24 hours later and 95 per cent for the stress-tolerant variety and 90 per cent for the control crop. Bottom line is that picking a tolerant variety can help a lot, but so can keeping cold water away from that crop for the crucial first 24 hours.
When it comes to soybeans, Deb Campbell, who runs Agronomy Advantage Inc. in Western Ontario, thinks producers can push the envelope. Long-term data say early planting, even in the cold, gives yield boosts of around five bushels per acre. That requires management: plants will be spending more time in the ground so seed treatments are crucial.
But early planting helps the plant avoid moisture stress at pod fill. And Campbell had a field that got snowed on two days after planting and still yielded 83.5 bu/ac.
Planting early soybeans is mostly a capacity issue, she noted. Planters are busy with corn. “But the yield benefit, at the price of beans today, is certainly there,” she said. “Keep pushing this window.”
