Do tropical homegardens elude science, or is it the other way around?

The terms multistrata systems and homegardens, which are used synonymously for the purpose of discussion in this paper, represent a group of seemingly sustainable and profitable agroforestry systems in the tropics. Although practiced for a long time, the systems have been little studied, and most reported studies are descriptive and limited to the identification of plant species involved and location-specific information on their yield and management. The conventional mass-balance approach to estimating the extent of nutrient cycling in some of these systems has raised alarms about potential danger of excessive rates of soil-nutrient depletion from the systems and their consequent unsustainability. Yet, in the field, the systems seem to defy such predictions. Furthermore, these systems that provide sustenance to millions of farm families defy the market-superiority paradigm of neoclassical economics. These contradictions arise, perhaps, from our failure to understand the systems in their right perspectives. The methods and criteria that are used for assessing the productivity and profitability of market-oriented, single-species, agricultural and forestry enterprises may not be appropriate for understanding the ecological and economic 'mysteries' of the time-tested multispecies systems. These systems can contribute greatly to our efforts to develop sustainable agroforestry systems; but new initiatives are needed for accomplishing such a goal. The efforts should start with the collection of basic statistics on the area and number of people involved, and proceed by developing appropriate methodologies, in much the same way as agroforestry research was initiated more than two decades ago.[PUBLICATION ABSTRACT]