Regarding your garden, and I'm surprised that no one has mentioned this yet, you can give your chickens a very special treat and greatly benefit your garden by letting them forage. Wait until the last harvest, then let your chickens have full reign in your garden area. They'll chomp up all the spent vegetable remains, turn it all into the best fertilizer available and even dispose of every single weed seed for you.
Once the garden area is barren, lock them out again and till their contributions into the soil so that the natural bacteria can process it over the winter. Next spring plant as usual, no additional fertilizer needed.