DES MOINES, Iowa — The sporadic weather that’s plagued the Midwest the past several years has farmers thinking ahead to the possible advantages and risks of early planting this season.

“Predicting the best time to plant can be tricky, as each growing season provides unique environmental challenges,” said Imad Saab, research scientist in crop genetics, research and development at Pioneer Hi-Bred International, Inc. in Des Moines. “Emergence can be delayed or reduced if planting conditions are less than ideal, and this commonly leads to yield loss for the grower.”

Clarke McGrath, partner program manager and field agronomist at Iowa State University’s Iowa Grain Quality Initiative, however, said early planting is typically a good thing, as long as crop insurance guidelines and good agronomic judgment are used.

“We have drifted towards earlier and earlier planting dates over the years as genetics and seed treatments have improved,” he said. “Early-season vigor of our crops has come a long way, and the addition of seed treatments containing fungicides and insecticides helps protect corn and soybean seeds from more early-season pests than ever before.”

But while early planting can give farmers with many acres ample time to plant before rain, as well as more time for crop development and the ability to help reduce the effects of possible mid-summer droughts, the practice can still be a gamble.

“Usually both corn and soybean yields are higher if the crops can be planted by late April or early May,” said Jim Fawcett, ISU extension field agronomist. “However, if the crop is mudded in to try to ‘beat the clock,’ this can lead to problems throughout the season such as rootless corn and K-deficiency (potassium) in corn.

“Planting soybeans too early can increase problems with sudden death syndrome and bean leaf beetles. The mild winter may mean more problems with bean leaf beetles this year, although numbers have been so low it may take more than one mild winter to see big problems with this pest.”

McGrath said one of the biggest threats with early planting that farmers have talked with him about is extended cold, wet weather than can push the limits of the seed and the treatments.

“We have seen great early-season planting conditions where a lot of corn and beans go in the ground, and then a stretch of ugly weather hits,” he said. “We can end up with stand loss from insects and seedling diseases. But most of the time, this is spotty in fields or in areas, rather than widespread.”

The other threat, McGrath said, is frost, “but unless it’s a really heavy freeze that penetrates into the ground down into the seed zone, corn can bounce back pretty well, since early in the season the growing point is belowground.

“Luckily, by the time beans are coming up, late heavy frosts are a relatively low risk, but occasionally, we see them in low-lying areas.”

In addition, as corn populations increase and the speed of decomposition decreases (because of fewer insects and less disease in the stalks), Fawcett said “we are seeing greater and greater levels of corn residue.

“This hasn’t been a big issue yet for soybeans, since they emerge through the residue fairly well and can compensate for reduced stands, but it can be a special problem for corn-on-corn,” he said.

Fawcett said tillage on non-erosive fields is one option for managing the residue or having residue managers on the planter.

“Soils do warm up more slowly the higher the residue cover, so this would also be a consideration in deciding how early to plant,” he said. “Eventually, one option may be to harvest part of the stalks for production of cellulosic biofuels, since many fields have more residue than what is needed for soil conservation.”

Aside from tillage issues, McGrath said another essential factor is seed placement. “Right spacing, right depth, proper seed to soil contact in the bottom of the trench and opening and closing the seed trench without sidewall smearing or compaction are all critical,” he said.

Saab said good residue management can range from using row cleaners to clear the planting row of residue, to planting slightly deeper to overcome moisture and temperature variability while ensuring good seed-to-soil contact. He recommends planting well-drained, low-residue fields first, as well as avoiding working the soil when wet to minimize compaction and sidewall smearing, as well as choosing a hybrid with the right trait package for high-residue environments.

To maximize emergence, Saab said growers should avoid planting until soil temperatures are 50 degrees or higher, and preferably with a near-term warming trend.

“Studies have shown decreased emergence rates with cooler soils or when an extended cold front moves in right after planting,” he said.

Still, the main challenge every year with early planting is the weather, Fawcett pointed out – especially the mild winter with reduced snow cover, which reduces the chances of having excess soil moisture that could delay planting, which also can occur with excessive rains.

“If temperatures remain at or above normal and we don’t have more than normal rainfall in the next six weeks or so,” he said, “we should see a good start to spring planting.”