Sustainable food production for a complete diet

Home gardens provide relatively little supplemental food or in come for most practitioners in the United States (Utzinger and Connolly, 1978; Wishnetsky and Cash, 1976). but they can be important sources of supplemental nutrition and income for people in developing countries (Gershon and Yen-Ching. 1984; Mullane, 1981; O’Brien-Place, 1987; Yoon, 1983). Family gardens can provide a form of food security if they are keyed to specific nutritional needs (Gershon and Yen-Ching. 1984; Popkin et al.. 1980). The extent to which it is practical to produce a complete diet in a garden is unknown. Duhon and Gebhard (1985) are representative of an organic fanning movement that advocates complete food independence through sustainable family gardens. They estimate that a complete diet can be produced on as little as 100 m of land with few external inputs. NASA estimates of the space to produce a complete diet are as low as 25 m (Hoff et al., 1982). To our knowledge, these estimates have not been verified experimentally. We have helped to develop the food production system for Biosphere II. a closed, I-ha ecosystem in which eight people will grow their own food using natural desert soil and sustainable meth ods. As a pretest of the system, we have attempted to produce all of the elements of a complete diet. made up of a diverse collection of food crops, on a minimal area in Tucson, Ariz. The experiment tested the feasibility of producing all or most of a family’s nutritional needs on a small piece of soil using manual labor and no outside inputs. The experiment was conducted in a greenhouse to simulate the continuous cropping conditions that exist in tropical locations (Sanchez and Benites. 1987) as well as the conditions expected in Biosphere II and possible future space habitations (Hoff et al., 1982).