Have you checked out the Conversations section on ECHOcommunity.org? A conversation in May centered around emergency gardens, especially in light of COVID-19 quarantines/shut-downs. An ECHO network member who works in Guatemala asked for ideas for growing nutritious plants in limited space.
The responses ranged widely. Several people suggested specific plants that mature quickly and that grow well in small spaces, with cautions to first look at what people already eat; to consider what kind of food is most needed (e.g., carbohydrates, protein, or vitamins); and to source food and plants locally as much as possible. Other commenters reminded readers that diluted urine is a readily available source of nutrition for plants, and can also provide much-needed nitrogen to hasten the speed at which plant material turns into compost. The conversation also includes several suggestions for making simple sack gardens. Check it out!