Since water, rain and soil health are concerns for you I would highly suggest you mulch the ground as heavily as possible. Use grass, weeds, and anything organic you can cut down to put over the top of the ground.

This will help you in a lot of ways:

1. Keep the sun directly off the soil so it will stay cooler and more moist
2. Holds water in, it keeps water where you need it rather than evaporating
3. Fungus and beneficial bugs will break down this organic layer and create nutrients for the soil. They will also create networks for inter plant communication and nutrient pathways.
4. Prevents erosion of the top soil from rain and wind. It keeps nutrients in the soil.
5. Weed prevention.

Also consider growing a cover crop. One of the best I have found is sweet potato, not only will you get a crop from it but the plants that grow up higher than this will not be effected.

If you have anyone around who grinds up trees, or limbs from pruning the wood chips laid down about 6 inches deep is like magic. Each year you lay down more. You no longer need to turn your soil either. You just did down to black earth to plant again. It prevents weeds and make it so easy to pull out weeds that do come through.

sweet potato as ground cover and inter cropping.

Wood Chips used for mulching. I get these from our timber market where they plane boards. Usually they have these more course ones and then finer like sawdust. I like the more course ones as they are not as uniform and heavier to stick to the ground. They come from a lot of different types of trees which is good, but you should try to get wood chips that contain the leaves, branches, bark and all parts of the tree if possible.