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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #59224


item Churchill, Donald
item Alderman, Stephen
item Mueller Warrant, George
item Elliott, Lloyd

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary: Grass seed production fields in Oregon's Willamette Valley have traditionally been burned after harvest to dispose of straw residue and to destroy the next season's potential pests and diseases. The practice of open field burning may be entirely eliminated within the next few years. Low-input, in-the-field composting could provide an alternative for grass seed straw utilization. Composting of grass seed straw into an easily spread soil amendment has been shown to be possible without the addition of a high-nitrogen component such as inorganic nitrogen or manure. However, since this form of composting does not generate the uniform high temperatures, survival of weed seed and pathogen propagules contained in the compost is a concern. The objective of this research was to determine how different compost management procedures affect the survival of weed seeds and other organisms. This research examined the effect of different grass seed straw compost management options, specifically straw collection method, depth of burial and numbers of turns on the survival of five species of seeds and seed pathogen propagules. Annual bluegrass, ergot, annual ryegrass, and blindseed all had 0% survival after 6 turns while tall fescue after 6 turns had .21% survival. If composting of waste grass straw and its amendment to soils used to produce grass seed crops is to gain acceptance, it is important that the presence of viable weed seed and pathogen propagules be reduced.

Technical Abstract: Seeds of annual bluegrass (Poa annua), annual ryegrass (Lolium multiflorum) and tall fescue (Festuca arundinacea Schreber), and propagules of two fungal pathogens of grass Gloeotinia temulenta and Claviceps purpurea were placed in mesh packets and inserted into compost windrows of perennial ryegrass straw. Compost treatments included two types of straw, three methods of turning and three depths of seed or propagule placement. Packets were inserted to depths of 0.3, 0.6, and 0.9 m and corresponding internal temperatures were recorded weekly. Windrows were turned either 0, 2, 4, or 6 times over an 8-month period. During the 1992-93 season, windrows were turned with a commercial straddle-type compost turner and in the 1993-94 season windrows were turned with a tractor front-end loader. Composting proceeded without addition of nitrogen except for that present in the straw and without water beyond normal rainfall. Survival of weed seeds and pathogen propagules decreased with numbers of turns but was not related to straw collection method, depth of packet placement, or method of turning. Based on a lease significant difference test, this study demonstrated that to minimize survival of annual bluegrass, ergot, annual ryegrass, tall fescue, and blindseed required at least 4, 6, 2, and 2 turns, respectively for maximum reduction in survival. The only seeds and pathogen propagules to survive after 6 turns was tall fescue which had a .21% survival.