By: Elizabeth Cronin

A recent study by North Dakota State University researchers at the Carrington Research Extension Center helps farmers determine strategy for growing winter rye as preceding cover crop for dry bean.

“If dry bean is planned for 2023 following this year’s small grain, an excellent cover crop option that will provide benefits when planted this fall and into next spring and early summer is winter (cereal) rye,” says Greg Endres, North Dakota State University Extension cropping systems specialist.

Winter rye is a common cover crop used in North Dakota and has many advantages when properly managed. Expected advantages when established prior to dry bean production and with timely termination, include reduction in soil erosion, supplement weed management, utilize excess soil moisture and increasing long-term soil productivity.

The NDSU Carrington Research Extension Center conducted a study beginning in the fall of 2017 with the seeding of winter rye to provide living ground cover in the fall and spring prior to pinto bean production. Study objectives included determining optimum time for terminating rye based on bean planting date, assessing weed suppression and measuring productivity of the bean crop. The study was completed in 2021, providing a four-year database on the production strategy.

Findings of the study include:

  • Pinto bean seed yield with preplant terminated rye was similar to yield with the conventional-tilled production system check.
  • Delay in terminating rye until near or after dry bean planting allowed the rye to deplete topsoil moisture that was needed to timely establish bean plants and negatively impacted bean plant development, canopy closure and seed yield.
  • Dry topsoil conditions during early bean plant establishment throughout the years of the study indicate rye termination at least two weeks before bean planting is suggested with similar environmental conditions as experienced in Carrington.
  • Delayed rye termination did provide benefits of increased ground cover during the crop season and weed control similar as achieved with pre-emergence herbicides. Weed suppression with rye can be considered another management tool to supplement herbicides and other cultural weed control methods.
  • Adequate topsoil moisture during bean planting and plant establishment would allow extended benefits of the live rye cover crop at planting (“green-planted beans”) while maintaining seed yield potential.
  • Soil moisture status and precipitation forecast should be taken into consideration when determining the best time to terminate rye at a particular location.