Wet Spring Cover Crop Strategy

Let your cover crops grow a little longer in the spring – especially if it’s been raining a lot. This can help no-till farmers avoid a delay in planting corn and soybeans because of soggy field conditions. 

Heidi Reed is an extension educator at Penn State University.. She says over three-years, they tested five sites where they planted into green cereal rye cover crops and compared it to cereal rye that was terminated before planting They wanted to see how this affected soil moisture levels.

"We found that in both corn and soybean planting green reduced soil moisture in the top three inches of the soil profile significantly compared to our cover crop that was pre-plant killed," says Reed. "And then, as we continued to measure soil moisture through the growing season, we typically saw that soil in the planting green treatment was more moist compared to the pre-plant kill."

The study showed that soybean yield was not influenced by planting green, but corn yield was. Reed says the corn stand reduction could be due to the cooling of the soil by the biomass, or the cover crop devouring the available nitrogen.

If you’d like to give this method a try, she recommends using best management practices.

"We would recommend reducing the cover crop seeding rate to about half a bushel compared to a full rate of a bushel or greater. That can help there be a manageable amount of biomass in the spring for planting green," says Reed. "And then also, not applying too much fertility because that fertility can cause the cover crops to grow really quickly and can just make management difficult."