Come now, mechanized farming isn't all bad. Small engines have brought /billions/ of people out of poverty. My late grandfather switched from a dozen horses to

Come now, mechanized farming isn't all bad. Small engines have brought /billions/ of people out of poverty. My late grandfather switched from a dozen horses to one quadbike, tripling output and halving the amount of work he had to do. This 'third world' you are thinking of has been buying small, efficient engines for tractors and pumps for most of the last century. The spike in oil use for that was in the early 60s. Yes, there are some countries where every single farmer doesn't have access or purchasing power to buy a small tractor but they are the exceptions, not the rule. I don't know why you want to damn billions of people to a life of manual toil when you yourself have access to labour saving machines (you are on a computer). The problem isn't mechanization, the problem is scale. As for sustainability, I've seen farmers in Papua New Guinea running tractors on coconut oil before biofuels were in vogue. Fuel prices are high, fuel is a significant cost to agriculture. No one in their right mind wants to use more fuel than they must.