Reader submitted from Mother Earth News
Now, what about benefits of raising chickens beyond eggs and meat? Some people keep chickens or guineas in the garden solely for tick control–Free-range chickens are highly effective as a means of organic pest control.
Mother Earth News notes Chickens in the Garden: Organic Pest Control in recent reports.
Putting a value on lowering your risk of catching Lyme disease is pretty difficult — we can, however, estimate the value of the chicken manure fertilizer you can harvest from each bird. Chickens can use only a fraction of the energy from the grains they are fed; they excrete the rest in their manure. A backyard flock’s poop, if applied correctly and especially if combined with high-carbon matter — such as wood shavings, straw or leaves — adds nutrients to the soil and increases the soil’s organic matter content.
Each bird produces about 8 to 11 pounds of manure per month, as reported by Ohio State University and the Hawaii Cooperative Extension Service. Fresh chicken manure contains about 1.5 percent nitrogen along with good amounts of numerous other essential nutrients. Because nitrogen is the nutrient that’s most often in short supply, we’ll use it to estimate the value of chicken manure fertilizer.
The 8 to 11 pounds of fresh manure produced by one chicken in a month contains 0.12 to 0.17 pounds of nitrogen. Each season, most garden crops require a target range of 0.25 to 0.33 pounds of nitrogen per 100 square feet, according to Knott’s Handbook for Vegetable Growers and Woods End Laboratory. One hen, then, ranging in a 100-square-foot plot would deposit enough nitrogen to support healthy growth of most crops in just eight to 10 weeks (assuming all of her manure, including from under her roosting area, is harvested). If you were keeping the hen in a portable pen on a 3-by-10-foot (30-square-foot) bed, then one bird would deposit the target amount of nitrogen in roughly three weeks. You’ll likely keep more than one bird at a time on your garden beds, which will require you to monitor the amount of time you leave them in one spot. You’ll only need to keep two birds on a 100-square-foot area for four to five weeks, or three hens in the same space for only two to three weeks.
Nitrogen is a challenging nutrient to manage in your garden — you can have too much of a good thing. If you apply excessive amounts of nitrogen, some crops — such as tomatoes — will not fruit well and will grow mostly leaves. Follow the guidelines previously discussed to ensure you keep your chickens in the garden long enough to add a good dose of plant-boosting nitrogen, but not so long as to cause unintentional damage.
Some fraction of the nitrogen in chicken manure is lost when it volatilizes into the air. You can prevent this by mixing the manure into the soil as soon as possible — watering it in if there hasn’t been much rain — or composting it. Some of the nitrogen present will be in a slow-release form, which soil microbes break down gradually, making it available later in the season or even the following year.
The Value of Chicken Manure Fertilizer
Your total potential savings from using your flock’s manure as homemade fertilizer depends largely on what you currently use to fertilize your garden. If you’re applying grass clippings, for example, then your fertilizer is already free, and using chicken manure may not save you money (although a diversity of fertilizer sources is always a good idea). If you are buying bagged organic fertilizers, then you’re probably paying anywhere from $10 to $35 for each pound of nitrogen. (Read more about the wide range of fertilizer prices in Build Better Soil With Free Organic Fertilizer!.) Applying those prices to chicken manure, each bird would then give you from about $20 to $70 of nitrogen fertilizer value every year. Ultimately, the value of your flock will vary based on the number of birds you keep, your management strategy, your garden size and your current fertilizer expenses. (For a full breakdown on the value of keeping chickens, see our Estimated Net Value of Keeping Chickens chart.)
Summary of the Benefits. Spend $30 per year to feed each hen, and you can get about 200 to 250 eggs; plus $20 to $70 worth of crop-boosting chicken manure; plus richer, faster compost (keep reading); plus organic pest control; plus great entertainment and the satisfaction of a more sustainable system.