What is this soil pathogen ? . . fungus?
I have a raised bed that has a five square foot patch of large clumps of whatever this white substance is - some of the clumps are football size.
It's probably hard to identify just on the visuals, but it doesn't look good to me . . .is it a fungus, and any ideas what I should do about it?
I'm in a community garden here in San Francisco, brought in about half the bed's depth of compost in last year, and dug it in way down about two feet. But only this one bed out of four has the stuff.
There was primarily lettuce in the bed, if that makes any difference.