Field Burning
Grass Seed Crop Residue Management
Grass Seed Crop Residue Management Reference List
The stubble and straw remaining in grass seed fields after harvesting seed is known as residue. Management of the post-harvest residues is an important practice in grass seed production. Crops residues are managed in grass seed fields for control of certain diseases and weeds, to stimulate seed yield in some species of grasses, to remove large volumes of straw and stubble that might interfere with crop management operations, and to recycle nutrients in grass seed fields. A broad range of grass species are grown for seed production in Oregon - these species differ markedly in their seed yield response to post-harvest residue management.
There are three primary residue management methods practiced by Oregon's grass seed growers:
1. Thermal. This method includes fire-based straw and stubble removal and includes field burning with full straw load in place on the field (open-field burning) and propane burning. In some instances, straw is removed from the field and burned in stacks. Field burning has been an effective, economical and controversial method of crop residue removal and pest control in grass seed crops for more than 50 years.
2. Clean non-thermal. This method is based on straw removal by baling, and removal from the field. Stubble reduction following straw removal with a flail mower may or may not be employed. Straw removed from grass seed fields is used for animal feed, especially for export markets, as well as other products. The straw removed from seed fields has potential for use a feedstock for the production of ethanol biofuel.
3. Full straw load. This method involves no straw removal as the straw is allowed to decompose in the field. Straw length may be reduced by flail mower and/or by combine straw chopper. The straw composts in place in the seed field thereby improving several beneficial characteristics of the soil.
Since 1980, grass seed growers have reduced the practice of open-field burning in the Willamette Valley from the predominant residue management method to a method that is used on about 10% of the grass seed crop acreage for the past 10 years. This reduction has taken place even as the acreage of grass seed crops has reached record levels of production.
The purpose of this site is to provide a bibliographic summary of relevant works published on the topic of post-harvest residue management in grass seed crops.
Figure 1. Trends in grass seed production and open-field burning of grass seed crops in the Willamette Valley.
Figure 2. Decline in the practice of open-field burning in the Willamette Valley.
