In addition to the mechanically-managed garden spaces, an even better method is the chickens! These chickens are in the garden that contained early season crops and was planted to buckwheat that was allowed to go to seed. Now, the chickens forage over the buckwheat and leave their trail of fertilization.
The left side of the photo shows ground the chickens have already passed over and the chicken tractor will now be moved downhill towards the camera. I like this because it cleans up the buckwheat and some other seeds but yet leaves some plant material that decomposes easily on the gardens over winter to protect the soil.