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:
The stubble and straw remaining in grass seed fields after harvesting seed is known as residue. Post-harvest residue burning has been justified on the basis of pest control and stimulation of seed yield. Public concern over air quality and the potential for adverse health impacts on the region’s residents has necessitated the identification of alternative residue management practices. Oregon legislation (SB 528) has, in effect, ended the practice of field burning in the western part of the state for most species except for fine fescue seed crops.
Our work on grass seed crop residue management suggests that the answer to this question depends on the grass crop species. On-farm trials over 60 site-years and in 6 seed crops species across Oregon were used to compare baling straw with and without flailing of the crop stubble. In several of our grass seed crops including perennial ryegrass, tall fescue, orchardgrass and Chewings fescue, the differences in seed yield for baling and post-bale flail chopping of a field were negligible and were not statistically significant. Thus, there was no requirement for flailing of these crops after baling of the straw in order to harvest good seed yields.
Grass seed harvest continues to progress here in the Willamette Valley and thoughts will soon turn to residue management.
Smoke plume from open-field burning in Oregon’s Willamette Valley in the 1990s. (T.G. Chastain photo)
I’m reminded each year at this time of the challenges of grass seed crop residue management in the 1990s and the transition from a burning-based system to one that involves management of the straw and stubble by using non-thermal techniques. This topic was addressed in a 1998 Oregon’s Agricultural Progress article linked below:
Here’s a new article from our seed production research and extension team on trinexapac-ethyl plant growth regulator (PGR) and field burning effects on the expression of yield components in strong creeping red fescue (Festuca rubra L. subsp. rubra) seed crops. The field trials were conducted in the Willamette Valley over a 4-year period at Hyslop Farm.
This article will appear in the next issue of Agronomy Journal and is a part of our series on PGR tools for use in grass and legume seed production. The product is marketed as Palisade, Moddus, and several generic products for lodging control in grass seed crops and legume seed crops.
Key findings of the article:
Fall applications of the PGR had no effect on seed yield components.
Culm length was reduced and lodging was lessened by spring applications of PGR in strong creeping red fescue.
Spring applications of PGR increased the number of florets produced.
A combination of burning and spring PGR applications increased seed number and seed weight, thus contributing to higher seed yields in strong creeping red fescue.
The stubble and straw remaining in grass seed fields after harvesting seed is known as residue. Post-harvest residue burning has been justified on the basis of pest control and stimulation of seed yield. Public concern over air quality and the potential for adverse health impacts on the region’s residents has necessitated the identification of alternative residue management practices. Oregon legislation (SB 528) has, in effect, ended the practice of field burning in the western part of the state for most species except for the fine fescues.