Posted: 03/08/2014 at 11:35
I agree with Dove. Aim for good soil structure and good nutrition. I would spread horse manure (from a source where no weed killer is used) and let the worms take it down into the soil also as much homemade compost as you can.
When I plant, I sprinkle organic chicken manure pellets a week or so before and gently fork them in.
The fact that things did well the first year and not now could indicate lack of nutrition, do you feed the plants while they are growing. Also have you checked for vine weevil in the raised bed?