Fertilizing late in the year does affect the quality of the fruit, and it can keep the tree from hardening off, like you mentioned. But unless you are keeping a really large number of chickens under the trees, I don't think it should be too much of a problem.

An article I found from the Ontario Ministry of Agriculture and Food said that a carbon rich cover crop, like Italian rye grass will suck up a lot of the excess nitrogen.

I think they are thinking of people applying a large ammount of commercial fertilizer, rather than someone with a few birds under the trees. I would go with the poultry guild, with moderate bird numbers and cover crops under the trees.

Comfrey is well liked by poultry, is a good bee plant for pollination, and is a nitrogen accumulator, taking nitrogen out of the soil. It can be invasive, or at least persistent in some climates, but chooks should keep it in check. Chives and garlic are good for keeping some bugs away from fruit trees, and liked by chickens. Chooks also like dandelions and all kinds of berries- raspberries, mulberries,and so forth.

I ran my chickens in my fenced 60x60 veg garden with 8 fruit trees in it for a month once the snow was out of there and before the ground was starting to warm and I was thinking of planting. I can attest that my trees had 50 times fewer flea beetles than my neighbor's trees that are 800 feet away. I will probably move their coop into the garden for the coming winter because the results were so dramatic. Sadly, due to neighbor's dogs they have to have some sort of fence around them at all times so they no longer free range around the whole place. Chickens and trees are definitely a good mix!

Hi,I don't usually post here, but saw yours and decided to answer, since I have two chickens and a small orchard of fifteen fruit trees that I planted six years ago. I highly recommend the mix. I also have a pot bellied pig, and I compost her manure along with the chickens. They free range all day, all year. It gets down to freezing here in the winter, and I haven't had any problem. I think that would only occur if you had too many hens in a small space. I also put down a lot of mulch. Our climate is severely hot, but with all of the trees and plants, the animals and I have a beautiful and comfortable environment. Also, the chickens are great for bug control. They gobble up grasshoppers and are comical to watch.
Stephenie