As farmers are waiting for soil conditions fit for planting, University of Minnesota Extension soybean agronomist Dr. Seth Naeve talks soybean planting.
Should I plant corn or soybeans first? A topic of debate relates to whether it makes sense to plant soybeans before corn. Rather than thinking about planting date and order from a yield standpoint, consider thinking about it from a risk-avoidance standpoint. Soybean yield potential in Minnesota with planting date tends to be flat through the middle of May, dropping by ½ to 1% per day that follows, with high yields possible when planted through May. Risks are higher early and late spring, with the beginning of May being the “sweet spot” between maximizing yield potential and minimizing risks due to a hard frost, cold or wet seedbeds. Naeve shares that planting order is a risk avoidance calculation, “The penalty for replanting soybeans is much lower than corn. Soybeans are fairly forgiving as far as timing and emergence dates. The corn yield response is sharper at the beginning of the year, we have a higher value crop, we’re just going to make more money from that early planted corn; but when we figure risk into it, it changes the calculation a little bit.”
Oftentimes one can replant soybeans without the significant drop in yield potential one would encounter with corn. The key is waiting to plant until soil conditions are fit and with the 10-day weather forecast in mind.
Soybean maturity. One should consider planting fullest-season soybean varieties earliest. While shorter season varieties will not gain yield potential with an earlier planting date, a longer-season variety will, adding another couple of nodes of pods when planted earlier compared to later.
Changes to the USDA-RMA earliest planting date. Recently, a multi-state group of university-based soybean agronomists developed a more realistic earliest planting date map based on recent warmer temperatures. The team used planting date data generated over the years to develop a series of models to model risk and develop earliest planting date maps relevant to states in the upper Midwest.
A recording of the full discussion is online: www.youtube.com/watch?v=ZQ665VJf82E.