Well composted chicken manure is okay as a top dressing. And putting a layer on the bottom of the beds is a great suggestion.

I don't have boards on the sides of my beds, so drainage isn't much of a problem, and I did as OM suggested and added some store bought sand to my beds when I made them. Our clay and rock soil doesn't drain very well and the trenches do fill up with water after a hard rain. But, over the years, the worms have worked that compost further down into the trenches they have started soaking up that water faster. The garden, and the trenches, sit above a small pond and, as I had hoped, the pond now retains water better too, and the level fluctuate less, or at least slower.

What I am calling trenches in my garden were based on water management techniques using "Swales" developed by a guy in Australia named Geoff Lawton. Mine, of course, are a very small attempt to take advantage of his work on this. But even as small as they are, the effect they have is pretty profound.

It's very interesting how land is transformed using swales to manage water. It's kind of like contour farming on a grander scale, but it's meant to optimize water retention, as opposed to managing runoff. Here, in the Ozarks, I think it could greatly increase forage yields in pasture lands, and potentially transform some of them into crop land.

There are probably a lot places in the West that could really benefit from these techniques. I doubt the West end of WA is one of them though

But just about anywhere, in your home veggie garden it can help decrease the amount of additional water needed to maintain your veggies, and that means you spend less time watering...