At this stage, theres not much I can think of. I would try using some worm casting teas, and add some worms if you can. If you are able to just catch some local worms they would do. The microbial life in the tea, and casting would help regulate the soil. The worms may (or not) eat on the remaining alfalfa if there is any. Worms don't actually eat the organic materials. They eat off the leftovers from bacterial decomposing. So my thinking is... More micro'beast, means more decomposing, means more worm food, means more casting for micro'best. This may be way off course for you, but I'm rather medicated at the moment, and it's all I got...:smoking:
Okay, I let this sit a bit, and have a better idea, maybe.
Short of disturbing the roots, and soil, you kinda just gotta find a way to live with it. The above would be most effective in my opinion, but the bottom is a bit more practical. (I use worms btw, great for the soil)
You could also do an enzyme feed. Different ways to go, you can buy something like sensizyme, or make it. To make it, go get some malted barley from a home brew store, I paid about $6 for a pound. There are different kinds (2 row, 6 row) but for our needs the cheapest is great. Take 1oz by volume of barley, and blend it into 1 gallon of water. You now have an enzyme feed, and it can be used straight. Some people say bubble it, but it is not necessary, as the enzymes are not living organisms, and it only adds dissolved O2 to the water (which is good, not necessary). Take this mix, and do a semi flush. Nothing crazy, just 20-30% more run off.
Hope it helps some bud.