Statistically, early seeding equals higher yield, at least over the long term. But how early can you seed without having a wreck due to cold spring conditions? Earlier than you might think, apparently.
Last spring, Jay Schultz started seeding his CWRS wheat (mainly Brandon, with some Eli and Viewfield) on April 15 — the earliest he’d ever started his drill.
“Normally, the majority of seeding in our area takes place in May,” says the south-central Alberta producer. “During wheat seeding, soil temperatures were five to eight degrees Celsius. At those temps, the wheat took longer to pop out of the ground and was much slower growing than at the end of May.”
Schultz closely follows the work of Brian Beres, a senior research scientist for Agriculture and Agri-Food Canada in Lethbridge, who’s been pushing the envelope for how early wheat can go in the ground without yield penalties.
Beres’s research shows there is no penalty to planting wheat at soil temperatures as low as zero degrees, in contrast to the conventional approach of seeding based on a date range in early May or at temperatures of 15 to 20 C.
It was a rough spring in southern Alberta: snowstorms and hard freezes followed seeding, says Beres. He was aware that a few farmers like Schultz were seeding early for the first time.
Beres admits he was nervous. “On the western Prairies we had multiple frost events late in the spring of minus eight or 11, and I was freaking out. I was thinking, ‘I’m going to get lynched here.’”
But in the end, the wheat ended up “just fine,” says Schultz. The top one-third leaf burned off some fields, but the wheat benefited from the extra snow moisture.
“We didn’t break any individual field yield records, but our overall yield for the farm was about eight bushels per acre higher than our previous record for HRS. In a very tough harvest year with slow-maturing crops and moisture hampering conditions, early-seeded wheat helped us get in the fields earlier than normal and end up with number one wheat quality.”
Optimal seeding temperature
Beres’s work on ultra-early wheat seeding systems ran between 2015 and 2018 in collaboration with Alberta Innovates, the Alberta Wheat Commission and the Western Grains Research Foundation. A second phase was funded by AWC, but Beres is still looking for funding to fuel a project on durum.
In the original study, Beres seeded at six soil temperatures in two-degree steps between 0 C and 10 C.
There were no yield penalties for wheat seeded even at the lowest soil temperature, but yields were most stable when the crop was sown in soil temperatures between two and six degrees C, he says.
In contrast, wheat seeded at more conventional temperatures between six and 10 C saw yield drags compared to the earlier treatments.
“If you want to improve stability without any penalties to yield — chances are you might even observe a bump in yield — 2 C should be your trigger,” he says.
In one site-year in the original study, when the team went in with a no-till knife opener, the soil was pretty tight and the drill ripped up soil aggregates, says Beres, but they didn’t observe the problem on any other fields. Out of an abundance of caution, his team is currently running an unfunded project at Lethbridge comparing the performance of knife openers to disc-type openers in ultra-early seeding systems.
He says producers should pay attention both to yield data and to long-term stability, where the earlier treatments consistently outperformed the later.
“That’s one concept I’ve been trying to drive home — it’s not just the yield results on a graph but superimposing variability over all these site-years to see what’s the most stable system, and it would seem the earlier treatments provided more stability.”
No varietal differences
That wheat is more resilient than conventional planting recommendations might suggest is a significant lesson. But Beres’s work also shows there was no difference in performance between cold-tolerant and conventional varieties.
To be clear, Beres says the team looked at only one set of cold-tolerant wheat germplasm from Lethbridge. He says there could be a role for genetics tailored to early planting systems to help wheat overcome abiotic stresses.
“But I do think one thing we’re overlooking if we get too hot on the concept of the varieties is the role of seed treatments,” he says.
If producers are considering trying out an ultra-early wheat seeding system, it’s strongly recommended they use a dual fungicide/insecticide seed treatment, he says. This significantly improves the plants’ resistance to abiotic stress.
In the original experiments, both cold-tolerant and conventional varieties were treated, which might have masked the genetic potential of cold-tolerant varieties, he adds.
Beres’s PhD student Graham Collier is working on a set of experiments around management techniques including the role of pre-seed burn-down treatments. He’s also looking at a range of varieties to see whether certain genetic backgrounds lend themselves to early seeding systems.
An ultra-early wheat seeding system isn’t going to work for every farmer every year, Beres says. Conditions have to be right for planting.
Risks include loss of crop stand due to freezing, increases in seed and labour costs, and equipment incompatibility with soil conditions. But the list of potential benefits is longer and includes early-season moisture capture, a longer growing season leading to potentially longer grain filling, early canopy closure and avoidance of some crop pests.
“I think there’s more of an opportunity than a lot of farmers realize. There will be years where it’s too mucky to get in there, but there will also be years where you can,” says Beres.