Another point made by Mazoyer is that large-scale farms are actually quite inefficient ; that economies of scale happen only up to 5-7 workers per production units, and that after that you meet diseconomies of scale.
Also, the amount of food GDP going to the producer will rise again : even France or the US spend ~15% of GDP on food, but most of that goes to Agrobusiness and supermarket nowadays, not farmers. i.e. food prices for the end buyer need not rise that much. Auferre, trucidare, rapere, falsis nominibus imperium; atque, ubi solitudinem faciunt, pacem appellant.
That's interesting... So what is the optimal farm size, in terms of people and land area? When the capital development of a country becomes a by-product of the activities of a casino, the job is likely to be ill-done. — John M. Keynes
Land area OTOH is very variable, depending on the type of production, the amount of capital available... A shepherd with a dog can look over a much larger herd than without...
The insight is that agriculture is very easy to decentralise, which is why economies of scale don't apply. Auferre, trucidare, rapere, falsis nominibus imperium; atque, ubi solitudinem faciunt, pacem appellant.