Thomas G. Chastain
Annual ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] seed crops have been produced on some Oregon farms continuously for decades without rotation of crops or farming practices. The long-term influences of this continuous cropping of annual ryegrass have not been examined nor have any long-term practices been evaluated in annual ryegrass seed production.
Long-term annual ryegrass cropping systems trials were initiated in the 2005-06 crop year in a project led by former OSU Extension Agent, Mark Mellbye. His vision was for a 9-year project to study the long-term effects of several cropping practices on annual ryegrass seed production.
While there are several long-term cropping systems practices studies in field crops such as wheat at a variety of locations around the world, no long-term studies in grass seed crops and annual ryegrass in particular, have ever been conducted. The following six cropping systems practices treatments were employed in the study:
- Continuous conventional tillage and planting system
- Continuous no-till planting system
- No-till/conventional tillage rotation (alternate year tillage)
- Volunteer/conventional tillage rotation (alternate year tillage)
- Burn and no-till/conventional tillage rotation (alternate year tillage)
- Volunteer/no-till/conventional tillage rotation (tillage every 3rd year)
The following were the primary findings of the study:
- Annual ryegrass seed yield varied with tillage and establishment system, and environment.
- No-till produced the lowest seed yields.
- Environment x system interaction effects governed seed production characteristics.
- Increased tillage frequency and residue removal are required to sustain long-term seed yields.
- Yield differences among systems were attributable to seed number.
This article was published in Field Crops Research and can be found at the link below: