cover crop for alleys in orchard

Looking for ideas on what to plant this fall and next spring as a cover crop for my fruit tree orchard.  
Weeds are the biggest problem right now.
I now have a crimper roller and was thinking of rye or alfalfa.  I have a lot of clay just  under a 6 to 12 inch soil layer.
I live in North Alabama so winters are sporadic and summers are hot and humid.  
What would make a good cover crop over summer to suppress weeds?
What would be a good cover crop over winter to keep the soil rich?

I have not worked in an orchard nor am I used to your zone but I do have family in Auburn Alabama!

I would advise you to look into triticale as a suppressing cover crop to manage weeds and as winter green biomass, it is easier than oats in terms of preventing accidental reseeding. Do some research and see if that might be an option that would work for your application as I assume you will need to crimp it. You could pair it with hairy vetch because it matures at the same rate as triticale and gets some legume benefits.

The hot season seems tricky, perhaps buckwheat and cowpeas? Kind of a similar arrangement as the prior one just different season.

I hope I gave you some ideas to look further into.

Hello,

I'm a big fan of white (Dutch) clover for orchards.  It's tough, covers the soil to prevent weeds and provides nutrition.  A side note is that I often seed very "heavy", meaning far more than the recommended amount of seed.  I usually water pretty heavy to keep it going in the summer.  

Of course every cover crop has pros and cons.  I'd ask you to think carefully about alfalfa because it has deep roots and it's a perennial.  By deep I mean several feet deep depending on conditions.  I'm a big fan of alfalfa due to its toughness and many other qualities and I've grown it commercially (a long time ago) but as a deep rooted perennial (think 20+ years often in the right setting) you need to be committed to it.  

I love legumes for cover crops.  I'm also a fan of hairy vetch.  It produces a lot of mass.  It's great to mow that mass and have all of that green chop to feed the soil and provide mulch.  Here's a lot of good info on it:

https://www.sare.org/publications/managing-cover-crops-profitably/legume-cover-crops/hairy-vetch/

If you're planning on mowing it for nutrients for the soil be sure to mow before it flowers because a great deal of the nutrients that would have been in the cut leaves go into flower production and you'll lose those nutrients.  One thing that I do is plant a variety of cover crops in the alley ways (each alley having a different one) and see which perform well in my soil.  Then I start narrowing the list down to see what performs best for my purposes.

I believe comfrey is a must in an orchard and planting it between trees is beneficial for the mining of minerals, green chop and most importantly it's ability to draw pollinators.  It's basically a bee factory.

I hope this helps!

I remember Dr. Redhawk had some comments on what he does  so I tracked several down.
"I chop and drop, rape, 7 top turnip, daikon, winter peas, even grains work well, just chop before seed out.

The best plant for preventing erosion is Lucerne (alfalfa) the roots are massive in number and deep in the soil (over 4 feet deep is normal), clovers are great for this too.

I use a blend of something around 20 different plant species for covers, four of them are clovers, buckwheat, alfalfa, cereal rye, fescue, annual rye, rape, seven top turnip and on and on.
The reason for this is to get variety and thus diversity along with the many different root growth patterns, bacteria diversity, fungal diversity, the more different plants that are used, the better the end result soil will be."
 

Buckwheat?  Grows very fast.

Alfalfa has a deep root system. This also means it may compete with your trees for nutrients and impair growth (several such studies show this effect with Black Walnut tree plantations). I’d suggest a beneficial cover like Hairy Vetch. That will fix nitrogen , and both it’s growth and the mulch left from mowing will suppress weeds

If you want a grass, brome grass isn’t too competitive with tree growth.