When you've got animals, their dung could be used as fertilizer on the farms and apple orchards.
I'm not a farmer, so I had to do some quick studies on the net....
The average manure produced per day is:
Cow, 36 kg/day 66% = 8672 Kg/year & 83% = 10906 kg/year
Horse, 20 kg/day 66% = 4818 kg/year & 83% = 6050 kg/year
Pig, 10 kg/day 66% = 2409 kg/year & 83% = 3029 kg/year
sheep, 2,0 kg/day 66% = 481 kg/year & 83% = 605 kg/year
chicken, 0,2 kg/day 66% = 48 kg/year & 83% = 60 kg/year
If the cows and sheep are confined indoors during feeding and milking, they produce 66% manure, since the 33% gets lost out in the pasture.
Cows confined indoors 6 months during winter, and at night time and milking produce 83% manure. since more can be collected.
The amount of manure needed per acre varies with different crops. Theese are my suggestions...
Grass = 5 ton/acre/year
fruit = 7,5 ton/acre/year
Grain = 10-15 ton/acre/year
Yields from a grain or cornfields:
1 of 3 is set aside for next years planting season.
1 part for seeding.
2 parts for human consumtion. Or 1 parts for human consumption and 1 part for animal consumption.
The amount of yield increase varyes with soild quality and crop type.
But a non scientific yield increase on crops could be:
grass = 15% yield increase.
fruit = 10% yield increase.
grain = 20% yield increase.
From this follows, that you also need 1 more building:
I present to you, The dungheap!