I've never taken an in-depth look at family or farm income. If I understood you correctly, non-indigenous farmers earn higher incomes than indigenous farmers.
When it comes to indigenous farmers, I think part of the answer lies in the absence of large-scale intensive farming operations. What we often see in Quebec is multinational companies working together. A person will buy their neighbour's farm and eventually the operation grows. An indigenous person, however, will never have the funding to take that same step or even access to those funding mechanisms. Quebec farmers have the support of quite a powerful organization with the capacity to help them. It's a matter of logistics. An indigenous person, though, could never undertake such a large-scale endeavour.
Coming back to Mr. Lévesque's situation, I would say he will likely get his larger production given what a resourceful person he is.