As you may know, I live in a rural area, although I grew up in the city and don’t know much about country matters. This seems to be the season for spraying the fields with naturally-derived fertilizer. The atmosphere is full of healthy vitamins, I’m sure.
Not too far away, there’s a farm with a very large, squat cylindrical tank, a “Slurrystore” product. Driving by one day, I was struck by the size of it, perhaps fifteen or sixteen metres in diameter, and say, four metres tall. (Consulting www.slurrystore.com, I guess it was a 50’x14′ Model 96A. They’re out of DeKalb, Illinois and work in feet.) Using simple mathematics, it’s easy to work out the volume of the tank, and thus estimate the maximum amount of animal waste inside. I make it about 800 tonnes.
Now, you may be thinking, “that’s a lot of shit”, but I assure you, it’s true. According to Slurrystore, a mature cow produces about 20 tonnes per year. You can see how it would build up, and quickly come to the obvious conclusion about what to do with it. Being a rich source of vital plant nutrients, it’s simply sprayed over the fields, leaving the air richly scented for days.
Actually, cow manure is one of the less smelly. Chicken shit stinks; horse is not bad; and pig excrement worst of all. There’s a clear evolutionary explanation for humans finding the smell of shit repugnant: it’s a likely source of infections, meaning that avoiding it is a survival trait. I guess we find the pigshit worst because of all farm animals they’re most like us in diet and metabolism.
The fields around here which are sprayed are pasture for sheep and cattle, so if you eat meat, you can assume that the animals you consume have been raised on excrement-sprayed grass. In the case of cereals and vegetables, I doubt if they spray over the growing crop (as I said, I don’t know much about farming) but it will be there in the ground for the plants to suck up.
But there is worse. It’s perfectly legal to use processed human waste as fertiliser too.