What if you plant soybeans this early?
If this week's USDA Crop Progress report was any indication, there could be a lot of farmers in Illinois ready to plant soybeans soon.
But, is it okay to plant soybeans this early? A lot of research shows there's not a lot of extra danger to planting in April and early May, but you also don't stand to lose yield potential if you have to wait until later than normal to plant. So, in the absence of any particular driver toward either extreme, it makes sense to proceed with planting soybeans when your corn's in the ground, says University of Illinois Extension agronomist Emerson Nafziger.
"We now have evidence that waiting until some date in May to plant soybeans may not be necessary or even helpful to yields,” Nafziger says. "Finishing corn planting and then starting soybean planting may be a good option, at least after mid-April. Soybeans planted in late March and early April this year are being affected by cool weather now, and while we don’t think they’re in danger, we’ll have to keep watching them to see if they grow well once it warms up."
The biggest variable right now is moisture. With some reports showing subsoil moisture's well short of normal in areas like northwestern Iowa, it's important to do what you can to plant around at least light rainfall for the sake of germination, Nafziger says. But, if you are short on soil moisture on the surface, don't plant deeper in an effort to nestle the seed closer to the moisture it needs, especially this early in the season when lower temperatures typically accompany rainfall.
"It is not a very good idea with either crop to try to 'plant to moisture' this early," Nafziger says. "Deep-planted seeds take longer to emerge, and that emergence can be reduced substantially if we get rainfall accompanied by lower temperatures."
If low soil moisture levels or temperatures right now aren't keeping you from planting soybeans, disease potential might. That's especially true with sudden death syndrome (SDS), U of I plant pathologist Carl Bradley says. Planting into soils that are on the cooler side can sometimes help SDS develop later in the growing season.
"When planting soybeans early during a time when soil temperatures are still relatively cool, farmers should consider the risk of SDS," Bradley says.
If you've got beans in the ground already and are worried about SDS, once they're emerged and growing, check your plants for yellow splotches on the leaves that develop into "interveinal chlorosis" where the leaf tissue is yellow but the leaf's veins are still green.