I have not tried a cover crop after planting fruit trees, but I have used cover crops to prepare my red clay soil for fruit trees. I haven't done a side by side comparison of trees grown with and without such preparation, but I can tell you that the effect on the soil is dramatic. Last August I killed a 8'X24' section of grass with Roundup, then a few days later planted the "soil builder mix" (45% Bell Beans, 15% BioMaster Peas, 10% Dunsdale Peas; 10% Purple Vetch, 5% Lana Vetch; 5% Common Vetch; 10% Cayuse Oats), which I covered with half an inch or an inch of compost. By October, it was 3 feet tall. Normally, if I stand on a garden fork in my lawn, it penetrates an inch or two. That's standing on it with two feet (I'm ~210#) In October, after a couple months of cover crop growth, I could easily plunge it in all the way. I've had the same experience with a cowpea/rye mix. An advantage of mixes is that different plants have different rooting patterns, the combination of which will break up the soil more thoroughly. For example, combining something with a deep tap root with a plant that has a broader spreading more fibrous root system will more thoroughly invade the soil with roots. I can't comment specifically on fava beans, but in general, cover crops are the real deal when it comes to loosening red clay soil. I also don't know if they are as effective on that gray caliche soil I've heard others talk about. Alex

Winter rye gives off a chemical that inhibits the germination of some seeds - tomatoes and lettuce come to mind. You need to allow several weeks between tilling in your winter rye and sowing seed. Also you do not want to allow your winter rye to get woody before tilling as it then has a high carbon to ntrogen ratio and can tie up nitrogen as it decomposes.

Ezzirah, If you are going to switch to no-till gardening, you wouldn't need a tiller and, if you use a tiller, you're really not doing no-till gardening, so I'm not sure how to answer this question. When I did no-till gardening our last three years in Texas, I double dug the soil the first year and amended it, built my raised beds above grade level on the double-dug beds by bringing in a mix that was 50% sandy loam and 50% compost, and did not rototill anything. With a no-till garden that has a cover crop planted in it, you can hand-dig the cover crop, although that partially defeats one of the main tenets of no-till gardening, which is to disturb the soil as little as possible. Or, you can pull out the cover crop and then place it on top of the soil surface so it can decompose, or you can place sheet plastic over the cover crop a couple of weeks before planting time and let the sun bake the cover crop to death. You also could just cut down the cover crop very close to the ground, leave the cut portions on top of the ground to decompose and plant through the stubble. This works better if you are transplanting transplants into the stubble area, or sowing large seeds like beans or corn. It wouldn't work very well with small-seeded crops. I have a rototiller and a small cultivator that is, essentially, a mini-tiller and I generally use them only when breaking ground and adding organic matter the very first year. After that, I just use handtools and try to turn over the soil as little as possible. Dawn

How big an area are you talking about? Does it need to be a legume or would something like a wheat or rye work? I think any legume would be prone to damage by rabbits and voles, but if it is a smaller area you could try some of the solutions listed in one of the vole threads listed here, or in the hosta or perennial forums if it is a smaller area. Some folks have found that bright shiny pinwheels (handmade or dollar store) around a garden bed also will discourage the critters.