Hi Michel,
The problem is, as even Will Allen will say, that these food production systems require constant subsidy through gifts of time, materials, and money, grant funding, or high-end markets where clientele can afford to pay a premium for local food. In other words, they are not sustainable. Furthermore, they only provide a small percentage of the calorie requirements for the local populations they serve.
The answer rests in the community adopting a production-to-consumption local agriculture system rather than attempting to establish a sustainable food supply through production only. That means the entire value chain gets taken into consideration when designing the local system. And it means starting at the point of consumption, i.e., total number of affordable, accessible, and healthy calories required to sustain local community members, designing the system backwards to the points of production, and allocating the revenue from sales of calories to community members such that all participants in the value chain, i.e., preparation, processing, production, and distribution, can, at a minimum, cover their costs. Such a system is very different than a "destroked" global system which is what one has when only localizing production.
My opinion for what it's worth...