University of Minnesota Extension

The spring planting season is soon upon us.  Prevent plant acres, or fields that were too wet to be planted to a cash crop last year, may need some special attention this season. As final preparations are made for planting, suggested strategies will depend on how these areas were managed in 2019. 

In fields where a cover crop was planted:

Be sure to have a termination plan for cover crops that overwintered, such as cereal rye. To protect yield, a general guideline is to terminate the cover crop 10 to 14 days prior to planting the cash crop, particularly if planting corn, since an overwintering cover crop can crate a “green bridge” for insect and disease pests. This timing can be less stringent for soybean, although it is recommended to terminate the cover crop prior to planting to minimize risk.

If a non-winter hardy cover crop was planted like oats, the cold temperatures of winter should have taken care of termination. Sometimes, however, some radish or turnips can survive the winter, or seeds will germinate in the spring instead of the previous year.  Check fields for survivors and apply an appropriate burndown herbicide around planting time as needed to ensure these plants do not compete with the cash crop. 

If a herbicide is used for termination, apply when the cover crop is actively growing and use an appropriate rate for the cover crop growth stage. 

For more details on spring management of cover crops and termination tips, see: https://extension.umn.edu/cover-crops/spring-management-cover-crops. 

As far as planting into cover crop residue this spring, most planters are well equipped to handle moderate levels of residue. Be sure to check for good seed to soil contact, planting depth, seed placement and any other issues, and be prepared to make adjustments if necessary. The following article provides useful tips for planting into higher residue situations: https://crops.extension.iastate.edu/encyclopedia/equipment-maintenance-planters.     

Note that cover crops can provide benefits like increasing infiltration, but planning ahead can help implement cover crops successfully. If you used cover crops for the first time in a prevent plant situation, but like what you’re seeing in terms of soil conditions, 2020 could be a year to expand your experiment to different species or planting methods. The Midwest Cover Crop Council and UMN Extension have Cover Crop Recipes and a species selector tool to help you make a plan for cover crops in 2020 available at http://mccc.msu.edu/.

In fields where tillage was used to control weeds and nothing was planted:   

Fallow syndrome is a risk in fields where there was little to no plant growth last year. Fallow syndrome occurs when populations of “good fungi,” called vesicular-arbuscular mycorrhizae (VAM), are dramatically reduced because VAM fungi need actively growing roots to survive.