Answer: Most turfgrass fungus is on the grass blades itself, not four inches deep so I'm not sure what you are dealing with. The best course of action is to dig out a sample, including the grass, roots and soil and take it to your local cooperative extension office for diagnosis. They can send the sample to the OSU plant clinic if they can't identify it for you on the spot. Once properly identified the staff can offer control strategies. Take the sample to: Benton County Extension, 1849 NW 9th Street, Corvallis, OR 97330-2144, Tel: 541-766-6750.
Best wishes with your turf!
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