The last thing you want to do is till in woody matter.. We all know the old tied up nitrogen issue.. IMO wood doesn't really have any business in a vegetable garden.. Besides the tying up of nitrogen it can harbor pests and disease.. If it is PURE pine bark and contains NO woody material what so ever than you'll get away with it, as it has a very high lignin content.. But you need to be sure of that.. Not worth it IMO.. It'd serve you (and your plants) better to stick with leaves and grass clippings if you're trying to increase organic matter.. The only thing wood should be incorporated in is a compost pile, so long as you add extra nitrogen to fuel its decomposition.. And always, mulch mulch mulch!
