There’s little doubt that in recent years Manitoba farmers have been getting the crop in earlier and earlier.
More tracked tractors, different seeder designs, management changes such as getting more work done in the fall and the ability to place more fertilizer at seeding time, has all added up, says Rejean Picard, a farm production adviser with Manitoba Agriculture based out of Somerset.
“Manitoba farmers have been around awhile now, and they’ve developed a fair bit of experience with early seeding,” he said. “I think generally they’ve got a pretty good handle on it.”
Even the most experienced operator can, from time to time, jump the gun though.
There are advantages to taking a deep breath and stepping back to wait just a bit longer, making sure the land is ready, Picard said.
Going too early can make a mess and offset the potential yield gains, to say nothing of the wear and tear on equipment and the added stress to the farm operators.
“Trying to muck a crop in doesn’t often pay off,” Picard said. “But again, I think most farmers know this pretty well at this point.”
If the land is ready to go, then the greatest risk is a late-spring frost that will hit yields hard, and again, most farmers are doing what they can to manage that risk.
“Most are very conscious of it, and are planting the crops — their cereals mainly — that are less susceptible to damage earliest,” Picard said. “They’re avoiding the more susceptible crops like canola, soybeans and flax, until later in the spring.”
Nobody doubts why the annual spring rush happens — years of research show earlier planting makes for higher-yielding crops.
Manitoba crop insurance data shows a clear yield advantage for almost every crop when it’s sown earlier.
One of the most important reasons for this is better utilization of soil moisture, and not just early in the season when the snowmelt moisture is present. Crop moisture needs and average rainfall seem to mesh better when a crop is seeded earlier.
Early seeding also often lets crops get the jump on weeds, though in a season with early-seeding conditions, weeds can at times get an early start too.
At times early seeding also allows crops to escape the worst of insect pressure. For example, wheat is only susceptible to wheat midge between heading and flowering, and the insects typically emerge in late June or early July. If the crop heads and flowers before this, damage is unlikely.
Many crop diseases are similar. For example leaf rusts typically come to Manitoba from late June to mid-July, with that date varying depending on weather and the development of the crops in the U.S. Early seeding can allow grain filling to begin prior to infections.
Other positive effects include flowering while temperatures are lower, making for better seed set and earlier maturity and harvest. Some studies also show a reduction in lodging in early-seeded crops.
There are two main risks for growers to remain aware of, according to Manitoba Agriculture literature — sowing into too-cold soils and the elevated risk of frost damage.
If the soil is too cold, the seed won’t germinate until it warms. The result can be uneven or inadequate emergence.
While the risk of crop damage from frost is well understood, it can be unpredictable at times. In part that’s because there is some evidence that some early-seeded crops will “harden off” and become more tolerant to frost.
There are two ways this mechanism seems to work. The first seems to rely on repeated exposure to cooler weather, leading up to a frost, allowing the plants to become ‘accustomed’ to lower temperatures. The second mode seems to revolve around plants accumulating more ‘solutes’ which are either soil nutrients flowing up from the roots or food coming from the plant leaves.
As Manitoba Agriculture explains in an extension release they are “much like antifreeze in your truck’s radiator.” Their presence actually raises the freezing point of the liquid present in these plant tissues.
Environmental conditions also play a role in determining the severity of frost damage. Moist soils can reduce the impact of mild frost because wet soil changes temperature more slowly than dry soil. The free water in soils outside the plants also helps buffer the plants because it will freeze before the water in the plant cells.
What happens after a frost counts too. If the temperatures slowly warm following a frost event, that can help minimize the impact on the crop. Rapid warming, dry conditions, wind and high evaporation all have the opposite effect, aggravating frost injury.
Soil temperatures key
Not all crops are created equal when it comes to germination
Staff – There can be a lot of variation between crop types when it comes to how warm the soil needs to be when planting.
Some typical minimum germination temperatures for major Manitoba crops:
- Wheat: 4C
- Barley: 3-5 C
- Corn: 10C
- Canola: 10C
- Soybeans: 10C