Should You Adjust Cover Crop Seeding Rates as Planting Dates Change?

Seeding cereal rye for the study. (Photo credit: Laurel Wellman, PSU)

Cover crop seeding is often the last box to check in the fall for farmers, and planting windows don’t always cooperate. 

Is there a way to use seeding rates to adjust for those early or late fall planting dates? That’s exactly the interaction Penn State University PhD student Laurel Wellman is exploring in a joint research project with the Northeast Cover Crop Council. Their findings, collected across six cooperating states, will help inform the council’s digital farm tools, the Cover Crop Explorer and Species Selector.  

One year in, and the Penn State team’s research has uncovered some interesting takeaways: 

  • Increasing seeding rates did boost early spring ground cover, and as a result, early season weed suppression. 
  • Early planting is the best way to achieve good biomass in the spring; regardless of seeding rate, early planted plots produced higher biomass.
  • However, regional differences matter. Boosting seeding rate was an effective way to boost biomass when planting late in the most northern states in the study (Vermont and Massachusetts). 

Dig into more details on the Penn State study and how the research is conducted in this video: 

For more information on using cover crops for weed suppression, see this GROW webpage.

Video by Claudio Rubione, GROW; text by Emily Unglesbee, GROW; photos by Laurel Wellman, PSU