The parts of the country with the most intensive animal farming have so much manure they don’t know what to do with. Manure is bulky — it has a low value per ton. This is a problem. The reason Iowa farmers are putting chemical fertilizers on their cornfields instead of manure is that it’s a lot more concentrated, so it’s cheaper to ship. In fact, it’s cheaper to ship oil halfway around the world, make fertilizer out of it, and truck the fertilizer to the farm belt than it is to truck free manure to the farm belt.
So people are doing various dodges to try to get around this. An article in Wired discusses duckweed’s ability to grow in manure lagoons and create a lot of starch for ethanol, which is a lot simpler and cheaper than growing corn, and it uses manure that’s just being wasted, anyway.
But you gotta wonder. It’s supposed to be like the old ads for Reese’s Peanut Butter Cups. “Hey, you put manure on my cornfield!” “Hey, you put cornfield on my manure!” Two great things that go great together.
You’re supposed to generate manure in an area where people will pay you money for it. You’re supposed to grow crops in an area where you can get cheap manure. In spite of the current namby-pamby attitude towards manure (“Ewww! It’s so organic and smelly! Shouldn’t we disguise its origins by composting it first?”), manure is something that belongs out in the field where plants can benefit from it directly. Plants know what to do with manure. Plants and animals co-evolved for 600 million years. Plants have this manure stuff figured out. Farting around with methane generation or composting is okay if you don’t have any fields to spread it on, but it’s second-best.
On a regional level, getting the location right is hard. Crop generation and animal raising have different needs and cost structures, and livestock production drifted away from the Midwest back when fertilizer was cheap. Now it looks like the poultry industry is shifting back towards the Midwest, with its insatiable appetite for fertilizer.
On a local level, though, your setup is more controllable. For one thing, it’s possible to go into the manure-generation business yourself, by raising enough livestock to generate the fertilizer you need for your crops. This is what Edmund Morris describes in his 1860’s classic, Ten Acres Enough, one of my favorite back-to-the-land books. (Go buy a copy.) Morris had a ten-acre farm near Philadelphia, where he grew high-grade fruits and berries. His expenses for manure were astronomical, so he started keeping cow-calf pairs over the winter. This operation only broke even when you considered just the cash, but was insanely profitable when you counted the value of the manure.
This can still be done today. Frankly, I’m amazed that anyone even considers going into the contract broiler-growing business without having enough acreage to use all the manure profitably, because it’s the only edge that’s available to you. But most people don’t, so manure is free, or at least cheap, near broiler-growing areas.
In our case, we do things the laziest possible way, and raise our chickens outdoors, where their manure is added to the soil with no intermediate steps. This increases the fertility of the pastures and keeps them lush and green through most of the year. Chickens can eat lush green plants but not mature, woody plants. A diet that includes lush green plants does wonders to the flavor and appearance of eggs and meat, so we’re getting direct value from the exercise, plus restoring the fertility of the land.