Should you plant soybeans shallow to get them out of the ground quickly, or plant deeper into more stable soil temperatures?
The correct answer is likely somewhere in the middle says Horst Bohner, Ontario Ministry of Agriculture, Food and Rural Affairs, soybean specialist. He’s monitoring a series of planting date and seeding depth trials at research locations across Ontario to gather new management insights for growers.
Spring 2020 is proving to be a great learning environment, notes Bohner. Excellent spring weather produced fit soil and a great opportunity for early planting; seeds were then put to the test as cool temperatures and wet soil conditions swept across the province in early May.
When it comes to seeding depth, early results from Bohner’s Bornholm, Ont., research location are already supporting his belief that one and a half inches is the best planting depth for soybean.
On April 22, Bohner planted soybeans into excellent soil conditions at a range of depths at the Bornholm site. On May 25, soys planted at one inch had finally broken ground and he is expecting a normal plant stand. Soybeans planted at one and a half inches looked similar. “Those beans are coming. Not as many are up but they will make it. They were in the ground almost 40 days before they saw any light. It’s pretty incredible that they are still pushing.”
But soybeans planted deeper are in trouble: “No doubt we’ll have significantly less plants per acre at two inches and at two and a half inches it’s going to be very ugly.” Bohner will be monitoring this research site and others throughout the season. RealAgriculture will have a full report later in June when stand counts are available to further confirm research findings.
At this point, planting at one and a half inches remains his standard recommendation. The one exception, says Bohner, is the seed has to be planted into moisture. “If you have to go looking for moisture, you go deeper than an inch and a half.”