I've encountered less about rice, but the transitional practices I described can be used in the (otherwise conventional) growing of corn and wheat and can produce comparable yields for lower cost to the farmer, directly in the case of reduced fertilizer cost, but especially when you factor in reduced losses to drought events from the ability for high organic matter soil to absorb and retain water, as well as greater resilience to disease and pest wipeouts due to healthier plants and a more diverse farm ecosystem. It's all somewhat anecdotal, though, since this sort of thing resists formal research, both from the funding angle (doesn't lead to profitable results for industry; not sexy/high-tech enough for ambitious academics and their departments) and the experimental design angle (too many variables; farmers are all trying out different things in different ways and different climates).
From the permaculture/food forest/holistic side, you can certainly vastly beat the economic output of conventional agriculture (e.g. just growing corn) on a $/acre basis when you integrate all the possible enterprises available (meat, eggs, vegetables, herbs, fruit, wood products, flowers, ecotourism, etc.). I'm not sure in terms of marketable calories per acre, i.e. stuff human beings actually want to eat, but I'd think at least within an order of magnitude of corn (eggs go a long way). But you're right, the bottleneck is availability of farmers, since one farmer with machinery can grow hundreds of acres of corn or wheat at millions of calories per acre. I think it's fair to say there's plenty of opportunity for people to become farmers if they want to, though, in that information is more accessible than ever and there's land available.
We do have the example of Gabe Brown [0], who I believe manages 1000+ acres regeneratively with only his family for labor. I don't recall any attempts to calculate his kcal/acre, though. Farmers are understandably more concerned with $/acre.
I’m sure you can see big gains with no til methods and soil improvements, no questions there really. However every regenerative/organic farms I’ve ever seen uses tons of labor and often a lot of unpaid “interns.” I’m not saying it’s impossible to do this commercially without questionable labor practices, I just haven’t seen it.
From the permaculture/food forest/holistic side, you can certainly vastly beat the economic output of conventional agriculture (e.g. just growing corn) on a $/acre basis when you integrate all the possible enterprises available (meat, eggs, vegetables, herbs, fruit, wood products, flowers, ecotourism, etc.). I'm not sure in terms of marketable calories per acre, i.e. stuff human beings actually want to eat, but I'd think at least within an order of magnitude of corn (eggs go a long way). But you're right, the bottleneck is availability of farmers, since one farmer with machinery can grow hundreds of acres of corn or wheat at millions of calories per acre. I think it's fair to say there's plenty of opportunity for people to become farmers if they want to, though, in that information is more accessible than ever and there's land available.
We do have the example of Gabe Brown [0], who I believe manages 1000+ acres regeneratively with only his family for labor. I don't recall any attempts to calculate his kcal/acre, though. Farmers are understandably more concerned with $/acre.
[0] https://www.youtube.com/watch?v=ExXwGkJ1oGI