I have RK nematodes-thinking of replacing soil in raised bed

[checkerkitty]

I was taken by surprise this weekend! I have a raised bed that runs the down the side of my house. It faces south-west and has some of the best light in my yard. It's prime tomato bed for me. I'm in the process of bed prepping for plant out. I pulled the last three neglected tomatoes and found the roots to be thickened and bearing a few knots each. This bed is mostly cheap, nasty top soil. We built the bed and filled it cheaply because we didn't know any better at the time. I've been amending it but now I've got some nasty beasties. Hybrids do fairly well here, but not OPs/heirlooms. I never understood why. So now I'm left with a decision. RKN are a pain in the backend to kill from what I've seen on Tville and around the web. That bed holds around a yard of soil so I think I'll just change it out. I'll do half horse manure/veggie compost and half something else (I'll have to think on this) with a layer of leaves and maybe dried molasses at the bottom of the bed just to give the good critters something nice to snack on. I won't put any sand in the bed. I can't control what is below the raised bed. Our neighborhood is built on an old horse pasture. There is a very thin layer of native soil/sand over lots of caliche.

This course of action seems logical to me. I think I would spend about 30-40 bucks on the new bed and would get immediate and hopefully lasting results. I've got a new compost area started in my yard so I'll have lots of leaf litter to add in next spring. If nematodes hate organic matter and love sand so much, I think I can take care of that. Has anyone else tried something like this? A local garden center said I should just get some beneficial nematodes and that would take care of my problem, but I'm not so sure about that. I haven't found any info on beneficial nematodes killing RKN. Actinovate looks like it will help, but I was going to use that anyway. I like the idea of a cover crop but it seems I need to take more drastic, immediate action. I would love to get other thoughts on this.

Christy