Q: Can I use chicken manure in my garden?
A: Chicken manure makes great compost for fertilizing your garden. However, we recommend you compost it first: don't add it directly in quantity. Uncomposted chicken manure is very "hot": too much nitrogen can burn your plants. Once your manure is composted, it is great for your garden, however.
Chicken manure does not acidify soil: it tends to raise the pH. Actually, one study demonstrates that chicken manure is as effective as lime in raising soil pH (making it more basic rather than more acidic). That same study shows that plants can absorb more calcium from the manure than from lime due to the fact that so much calcium and magnesium are contained in the manure. Poultry litter contains about 100 lbs. calcium per ton (dry weight). Composted chicken manure supplies nutrients and organic matter for your soil--improving its "tilth"--makes phosphorus more available and reduces your soil's aluminum toxicity.
You can read more about living sustainably with chickens.