An economist, possibly a moron, blunders into farming…
Entry into adjacent markets is a major source of innovation. So is there a case for dairy farmers also running chickens? Chicken manure is nitrogen rich and could substitute for urea, which is derived from fossil fuel. Instead of spreading urea, a flock of chooks could move in after the cows, spread out the cow shit, and add their own nitrogen rich contribution. There’d be a few logistics to sort out, but is it possible to get enough nitrogen this way?
Answer: perhaps, but you’d need a hell of a lot of chooks.
I reckon about its 15-20,000 per hectare to get the same dose of nitrogen in a day. Sounds ridiculous doesn’t it? And it probably is, but that stocking rate gives each chook 10 times its space in a battery, and they’d be able to move around, so it’d be heaps better for the chooks.
Here is the very rough calculation.
Farmers spread urea, which is 46% N, at around 80kg/ha, so thats 37kg of N/ha.
Each ton of fresh chicken manure has 11.8kg of N, so we need 3.1 tonnes of chicken poo per hectare to replace the nitrogen, although there may be some other efficiencies, like having the cow shit spread around. So the estimates below could be at the top end of what is needed.
You get 145g of poo/chook/day, so that means 21,408 chooks would be needed to supply the 3.1tonnes to the hectare.
This is a stocking rate of 0.47 sqm per chook. In batteries, they get 0.047, so the difference is a factor of 10.