I clean out the Deep litter that has been composting all winter in the Coop and till it in the Garden in the spring. I also add it to the base of my tomato cages and vine cages. I load several wheelbarrows full, it looks like dark brown crumbly dirt. It started out as grass clippings, pine needles, pine cones, fall leaves------basically anything and everything the lawnmower can suck up into the bagger. I also rake up the pine needle mulch under the pine trees by hand to add. I've never had any fertilizer "burn" problems. I use the deep litter method in a sub-ground level dirt floor in a coop built on a brick foundation I hand laid up. (Looks like it to, see my BYC page for pics of the Coop/Run). The chickens also have access to the Garden from fall till spring, so they've been scratching and direct fertilizing too. My Garden was thin weedy clay to start out with many years ago, now its a rich dark loam a foot deep or more. (thanks to the chickens)