Does anyone have any tricks up there sleeves to control Nematodes.

Justa and I have lost 1 Tomato plant and are loosing all of are beans to root knot. I've been doing some research on controls but haven't really found what I'm looking for. Soil Solarization or Introducing microbes that feed on Nematodes is kinda the direction that I think that we need to go at this point so... any suggestions?