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Posted 9 May 2018. PMN Crop News.

Planting Date - Stay the Course

Source: Article.

By Kris Ehler


Bloomington, Illinois (April 15, 2018)--This spring, plant some soybeans early and wait for “perfect” soil conditions for corn. April continues to be cold and wet, straining last fall and winter’s planting intentions. For many growers, those plans were to include early planting of soybeans. The data shows that early planting continually shows returns, but now the calendar looks to push us to late April or even May for the first planting opportunities. So, what will that do to those well laid planting plans? Unfortunately, for many growers, it means resorting to their “corn-first” plan.

I disagree with this approach, since going back to the corn-first plan means compromising your soybean crop. Data collected shows that we start to sacrifice 0.3 to 0.4 of a bushel per day when planting soybeans after May 10. We know that mid-late maturity soybeans offer the best opportunity to show yield increases when planted early or timely. Early maturity soybeans planted early don’t always show these same increases. In the past few growing seasons the later planted corn has proven to be some of the best stands, final ear counts and, ultimately, yields.

The recent weather trends are setting us up for success. One predominant trend is the extended length of the growing season. Eric Snodgrass, Agrible® co-founder and atmospheric scientist at the University of Illinois at Urbana-Champaign (UIUC), suggests that in Illinois we have seen a 10 – 20 day increase in the length of our frost-free season in the past 40 years. Growers are always concerned about full season corn hybrids not maturing prior to frost or having extra drying expense. Seed companies do a great job rating hybrid’s stalk strength, so growers know which hybrids can stand longer, allowing them to dry down in the field. Many growers also apply a fungicide that can help maintain stalk integrity late into the harvest season.

If delayed planting occurs, I promise you there will be fields worked and planted too wet. A tillage pass done when conditions are too wet will create a density layer that will not allow for optimal rooting to penetrate to soil moisture and nutrients below it. Corn’s shallow, fibrous root system will suffer more when planted into these conditions than soybeans more singular taproot system. That is one of the reasons you hear that soybeans are “more forgiving than corn.” Corn’s fibrous root system is subject to greater yield penalties due to planter side wall compaction.

My recommendation for delayed planting scenarios is to spend the first few days planting your fuller season soybeans. This will offer an opportunity to still capture some of the additional yield potential and allow the soil to warm and be completely fit for corn planting.

Achieving uniform emergence in corn will equate to higher ear counts at harvest. Delayed emerging corn plants that remain the ‘runts in the litter’ often never put on ears. Once soil conditions are fit for corn then plant the fullest season hybrids or early-mid maturity hybrids with poor stalk quality. Save the early maturity soybeans for last. Early beans will flower sooner and still having ample opportunity to take advantage of the longer days of sunlight.

None of us know what the growing season has in store, but don’t limit your yield potential by planting into less than ideal conditions.