Agronomy • 2023-02-08

Timing spring planting for corn and soybeans

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When it comes to spring planting, many farmers are concerned with ideal soil temperature, but soil conditions are just as, if not more, important. Here are some tips and advice on timing planting to maximize your crop’s yield potential.

When is too early to plant?

When deciding if it’s too early to plant in the spring, focus on ideal soil conditions, not soil temperature. If you’re going to err, err early.
Many farmers wait for their soil temperatures to reach 10°C, and they miss opportunities by doing so. Planting in ideal soil conditions is more important than planting in ideal soil temperatures. Especially when the alternative is planting in June.
If you take your farmer hat off and think like a scientist, your primary goal is to capture as much solar radiation as possible. Planting early can help you achieve that goal.
In Canada, our summer solstice / longest day of the year is June 21. To glean the most benefit from the growing season, strive to have your canopy closure near that point, whether it's a corn or soybean crop.
For example, corn responds extremely well to light intensity. As light intensity increases, so does the rate of photosynthesis. Capturing as much solar radiation as possible is the main driver of yields.

When are soil temperatures too cold?

Having your soil temperatures between 7°C and 10°C in the first 24 hours is perfectly fine. That might seem a bit cold. But, if you’re in ideal soil conditions, think of it like taking your seed out of the bag and putting it in a refrigerator.
In our northern climate, it’s a long wait for that ideal 10°C. Warmer soil temperatures will eventually come. However, there is no guarantee you will experience ideal soil conditions again.
Keep an eye on the three-to-five-day weather forecast. The first 24 hours after planting are especially critical, so you want to make sure a snowstorm isn’t right around the corner. When you have icy cold water freezing or melting onto the seed, that’s when you experience chill injury and get less than uniform, ideal emergence.

What is ideal planting depth?

A key component to planting early is making sure to achieve ideal planting depth, which is about two inches.
A lot of research shows that growers get more uniform emergence at two inches than at one inch.
With adequate planting depth, you create a buffer against colder temperatures.

Why is it important to assess your soil before planting?

With the number of acres that producers cover in a day and the size of the equipment, it’s easy to make mistakes. Taking the time to critically evaluate your soil is paramount.
When deciding whether soil conditions are fit for planting, it's critical to physically get into your field; don’t just drive by or swing in with a cultivator and make a big swath. You need to be on the ground.
Grab a spade, go out into the field and dig up some soil in a couple of spots to see what the conditions are really like.

While new technology is improving seed performance and better protecting against disease and insects, these innovations are not a substitute for sound agronomic management. The more you can do to ensure our high-yielding Pioneer products are going into the right environment, the better chance you have to maximize your crop’s yield potential.