Strategize cover crops like cash crops

Andrea Basche, assistant professor in the Department of Agronomy and Horticulture at the University of Nebraska-Lincoln conducts field research on Iowa and Nebraska farms, work that leads into optimizing cover crops on the farm.

In an Iowa Learning Farms webinar this week, Basche presented results of field experiments and how changing your perspective about cover crops can boost the benefits.

She says treating cover crops like cash crops improves the effectiveness of nutrient cycling, water storage and infiltration, and weed suppression. The benefits of these can magnify the overall impact of cover crops and potentially increase cash crop yields.

• READ MORE: How to keep nitrogen in the soil where it belongs

"It is well known that cover crops are beneficial to soil health and erosion prevention, but it is important to take a broad view of applying fundamental principles of agronomy to the multi-season crop rotation plan that includes cover crops," Basche says.

As interest in cover crops continues to grow, the strategies Basche shares can be used to help farmers achieve their goals.

Opportunities to optimize the cover crop growing season

Just as there is strategy and focus on planting dates, variety selection, seeding rates, fertilizer considerations, so too should there be for cover crops.

In particular, planting date and variety can be used to optimize the growing season, or the length of time the crops have access to heat, sunlight, and water for growth.

• READ MORE: Prioritize soil health to restore profitability and open new doors

Below are three strategies to consider carefully as you plan to incorporate and maximize cover crops on your operation:

• Interseed or overseed cover crops into standing corn or soybeans, at vegetative growth stages (June) or closer to harvest (August/September).
• Plant green: plant corn or soybeans directly into a live cover crop and terminate later.
• Drill cover crops after an earlier fall harvest that could be achieved due to an earlier spring cash crop planting, shorter season varieties, or different cash crops grown.

Field experiment and simulation takeaways

To really understand if and how cover crops can change, Basche and her team experimented with corn grown in three cover crop treatments in Nebraska.

• Corn grown in six N rates with three cover crop treatments
• Planting date: August 26, 2020 after oats
• Termination date: April 29, 2021
• Seeding rates:
  • Cereal rye at 60 pounds per acre
  • Hairy vetch at 25 pounds per acre
  • Mix of cereal rye at 30 pounds per acre and hairy vetch at 20 pounds per acre

The experiments' results and modeled simulation showed that:

• The difference between cover crop planting in mid-September and late October is 10 times more biomass and four times greater biomass when terminating at the end of April vs. the beginning.
• Above-average moisture and temperature can result in four times greater rye biomass than below average moisture and temperature.

"When we adapt our mind-set to think about cover crops like cash crops, it encourages us to consider how we can use more of the growing season to help the cover crops achieve the goals that we really want to have for them," Basche says.