Negative alleopathic impacts of green manure cover crops on a food forest.

In my densely planted food forests I hope for volunteers from plants that have gone to seed and where there is space I plant in cover crops as sort of an ongoing green manure to improve soil. Any thoughts on negative alleopathic effects specifically from clover/rye/vetch/peas/oats/alfalfa/barley when growing side-by-side with food forest crops.

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It's a good question. It'll be interesting to hear everyone's opinions on this.

I wish I knew where I read the research, but it said that grasses actively exude a chemical that kill bushes and trees. When a tree is established, then it's strong enough to hang with the grass. There is also research (again I wish I could find it) on sapling survivability and they found the number one predictor of success was whether the tree was put into a scraped out area devoid of vegetation . This would imply that the tree needs a period of no competition or it could mean the scraped area creates a bowel that funnels more water to the tree.

Soooo what to do with that? I would recommend against sowing wheat, barely or any other grass type cover crop. Clovers I think would be okay, but killing the existing grass around the area and mulching heavily is best.