How many people can land support?

[bigpaul]

sorry Mort wrong again, the UK is 60% self sufficient in food, thats official figures from the NFU(national farmers union) and much of what we do import is of the exotic variety which cant be grown here anyway.
what would change the game post SHTF is compost, fertilisers and pesticides which are all imported and would not be available, also on the low lands mono cropping is practised which takes more out of the ground and makes the ground infertile, that what all those imported chemicals are for.
as for land size, post SHTF we wont be farming large animals, heck we wont even be "farming" full stop, it will be more horticulture than farming, the land size will be determined by how much we can control, the more land one has the larger the group needed for labour and security, the larger the group the more land will be needed, its a vicious circle. small is better in both context.