With fertilizer prices climbing, some corn growers in Western Canada — particularly in Manitoba — went into the 2022 season with hopes of capitalizing on large N carryovers because of the drought over the previous two years. But a wet spring washed those hopes away, especially in sandier soil regions, as N leached out and yields were reduced.
Manitoba Agricultural Services Corporation reported 313,516 corn acres in 2022, down almost 15 per cent from 2021. In recent years they’ve ranged from 300,000 to 400,000 acres, with the highest at 406,620 in 2019.
The decrease was mainly due to wet planting conditions. “Had it been an easy or early spring, acres likely would have increased over 2021 because of the high grain prices,” says Morgan Cott, agronomy extension specialist for special crops with the Manitoba Crop Alliance (MCA). “Field plans had to change because fields were not drying up, the soil was still on the colder side, which meant slow germination, and seeding deadlines were approaching. A corn farmer knows to never ‘muck in’ corn seed in the spring.”
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Despite the wet start, Manitoba corn yields were above average due to the ideal growing conditions that followed.
“It was wet, but we also accumulated more heat units than normal, so the moisture, heat and sun all worked together to create fantastic growing conditions when the corn needed it the most,” Cott says. “The pollination period was not hot and dry like it has been the last two years, which are very harsh conditions for the most important reproductive stage. This year it was warm and we actually had rains in July, which is fairly ideal for pollination. Corn has its greatest water requirements during R1 and R2 (silking and pollination), and it is fairly rare that we get warmth (not blistering heat) and rains in mid-July together.”
Finessing in
It turned out that growers were wise not to put all of their nitrogen down at planting.
“By taking a split nitrogen application approach, it enables the farmer to spread out the risk a little and reassess the corn crop a month after planting to determine if it deserves more nitrogen and how much,” Cott says. “We have to do this in- season nitrogen application fairly early (around V4) so that there is little disturbance and/or damage to the crop. The early timing still makes it a difficult decision on how much nitrogen to top up with, but deficiencies can still be corrected at that time. Corn doesn’t start using the bulk of nitrogen until around that time and later through the growing season, so it is a common nitrogen management practice in corn.”
MCA has done a lot of research into in-crop N applications and Cott says the best practices seem to be either dribble banding liquid between the rows before a rain, or injecting liquid or anhydrous into the soil.
“If farmers apply liquid nitrogen (28- 0-0) as a foliar application, it is so stressful for the crop that it can set it back. It does recover but it is literally burning the leaves and no plant likes that.”
She says that in a year like 2022, supplementing N will make a difference in some situations but in others not.
“It is very situational and it didn’t/ wouldn’t necessarily make a difference in each field — it just depends on how much was there to begin with, whether the farmer held back on his fall or spring N prior to this corn crop, how much rain they got, when they applied their spring N, etc.”
Insurance a factor in Saskatchewan
Saskatchewan’s 2022 grain corn area was in the usual range of 12,000 to 15,000 acres, according to Saskatchewan Crop Insurance Corporation (SCIC) data.
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Late moisture in southeast Saskatchewan did create some problems with crop choices. “I know for sure some producers didn’t seed soybeans as they didn’t get in the fields until late May and this would have also impacted seeding of corn,” says Sherri Roberts, crops extension specialist for the Saskatchewan Ministry of Agriculture. “The cost of nitrogen would have been the biggest detriment to growing corn this year, as corn is a big nitrogen user.”
What may have affected the province’s grain corn area has been crop insurance coverage only in designated areas, and the need for a dryer most years.
“With the crop issues that have affected producers the past couple of years, most of them have to produce crops that crop insurance will cover,” Roberts says.
While yield data was not in at the time of writing, southeast Saskatchewan also had ideal growing conditions, so good yields were anticipated.
Roberts advises growers to choose varieties resistant to Goss’s wilt, which is expanding throughout the province.
“I believe the majority of corn producers are unaware of Goss’s wilt even though efforts to do extension messaging have been done,” Roberts says. “They connote the symptoms to early dry-down instead of a disease. As this disease is caused by bacteria, fungicides are not effective in its control. Selecting resistant varieties and widening rotations are the current methodology for dealing with this disease. Fusarium is also increasing in those corn fields where producers have done continuous corn on corn and widening rotations will also reduce this risk.”
Roberts also has advice for corn growers planting for cattle feed: they may want to try using corn pickers so whole cobs can be harvested and ground into nutritious feed.
Alberta – steady under irrigation
Alberta grain corn acres were down slightly, probably due to good prices for other crops, but growers who stuck with corn enjoyed good conditions with consistent growing days once they got beyond the cool spring.
“We had a very dry and cool start,” says Nicole Rasmussen, Pioneer Brand agronomist with Corteva Agriscience. All grain corn in Alberta is grown under irrigation and is confined to the south of the province, with the northern, dryland areas growing silage and grazing corn.
“Cold irrigation water can slow early growth, but we are hearing of yields slightly above average; in the 10 to 15 per cent range,” Rasmussen says.
Because grain corn is irrigated in southern Alberta, the carry-over of N due to drought was not a factor, so growers who followed regular N applications didn’t see any deficiencies. On the insect front, there was more European corn borer in areas where it had not been seen before.
“It stretched northwest of Edmonton, causing some issues … especially in the early season where hybrids don’t have Bt protection,” Rasmussen says. “We also saw root lodging and green snap this year across the province. Some large summer storms hit the corn when it was at its vulnerable rapid growth stage, and high winds and lots of rain were to blame. I don’t believe it was significant for many growers, but it’s definitely not issues we are used to seeing here.”
– This article was originally published in the January 2023 issue of the Corn Guide.
