Early planting has its benefits, but be sure to weigh your options before heading to the field.
The so-called polar vortex gripping much of the country right now has many farmers dreaming of spring and planting season. That’s true for veteran corn grower, Bob Kochendorfer. "Earlier and earlier every year it seems" is how Kochendorfer describes the start of planting season for corn on his south central Michigan farm near Jonesville.
He says advancements in seed technology, equipment and agronomic know-how have moved the starting date for corn planting in his area from the end of May, just a generation ago, to late April today.
Kochendorfer, other farmers, and agronomists cite a number of benefits associated with early planting. For one, the crop is often able to flower before mid-summer heat and dry soils can take their toll on pollination. Early planting can also help minimize the impact of some insects, lengthen corn growth and development time, and give the crop more time to dry down in the field prior to harvest.
The latter is one of Kochendorfer’s favorite early planting benefits. "A lot of times I can avoid paying so much out-of-pocket for drying costs, once corn is in the bin," he notes.
Even so, the veteran corn grower is unwilling to pull his planter into the field just because the calendar registers a specific date. Instead, he uses a variety of factors to determine the planting start date, a decision he says that almost always pays off at harvest.
Part Science, Part Art
Having an adequate soil temperature is Kochendorfer’s first and primary consideration. He says experience over the years has shown him that soil temperature can support or stall corn emergence and growth.
"I typically start planting when soil temperatures reach between 50 and 52 degrees Fahrenheit," he notes. "I also consider the weather outlook for the following week or so. I want to know, if at all possible, that it won’t rain or turn cold during that timeframe."
Imad Saab, DuPont Pioneer seed researcher, agrees with Kochendorfer’s strategy.
"Early planting carries an increased risk of stand loss due to the potential for damaging frosts and cold snaps in early spring, which can then require replanting," he explains.
Saab also cautions farmers who are planting into fields with low organic matter. "With lighter soils planted early, be aware of the potential for large temperature swings that can affect emergence, especially if nighttime temperatures dip into the 40’s," he adds.
Kochendorfer says he stays in close contact with his agronomist for regular updates on his area soil temperatures. Farmers who want to achieve the same benefit on their own can use an inexpensive soil thermometer, typically costing less than $25, to gauge the soil temperature at 2" to 3" below the soil surface in their fields at the same time each day.
Too much moisture at planting is another reason Kochendorfer will refrain from planting corn.
Mudding in a crop is rarely if ever a good idea, notes David Nicolai, University of Minnesota Extension educator. He says that the advantages associated with early corn planting dates can be lost if soil is too wet.
"Sidewall smearing can occur as planter disk openers cut through wet soil, resulting in compacted soil around the seed that is difficult for seedling roots to penetrate," Nicolai explains. "Seed furrows can also open up after the soil dries when it is too wet at planting. In addition, soil compaction from heavy machinery on wet soil can reduce yield this year and in the future." Planting into cool and wet soils also increases the potential for seedling diseases, he adds.
"Growers believe they’ll gain growing days and yield by grabbing an early planting window," Saab says. "This is usually true if the crop is planted into a well-prepared seedbed with adequate temperature and moisture. But if you expect a cold, wet spell shut down your planter for at least a couple of days ahead of that event to allow the seeds to begin to soak water and germinate under more favorable conditions. This will likely result in more rapid and uniform corn emergence and translate into higher yields."
Here are three additional tips Saab offers to help growers weigh their early planting options:
- If planting in a field with high amounts of residue, consider strip-tillage and residue cleaners to improve seed to soil contact and warm the soils up faster. Kochendorfer uses spring tillage with a chisel plow to open and warm soils on his hilly fields prior to planting. He says spring tillage also helps minimize the opportunity for soil runoff and erosion in those fields.
- When selecting hybrids, choosing those with higher stress-emergence scores can help reduce the risks associated with planting in cold-stress conditions.
- Consider your planting depth. Saab says a 2" planting depth is considered optimal for average conditions. Planting depths less than 1.5" can expose seedlings to wide swings in temperature and moisture and often result in poor root development and seedling lodging.