A quantitative approach for assessing the productive performance and ecological contributions of smallholder farms

A pragmatic framework for monitoring, modelling, analysing, and comparing the state and performance of integrated agroecosystems is proposed. Four smallholder rice farms (1.36-2.76 hectares) - including monoculture rice and diverse rice-based systems with livestock, aquaculture, tree, and vegetable components - are used to illustrate the approach. Data collection employs a range of techniques (bioresource flow diagramming, farm transects, direct observation, field measurements, farm records, and informal discussions). Weekly data gatherings are used to construct annual, mass-balance, nutrient (nitrogen) flow models of each farm system. The models form the basis for quantifying a series of agroecological system attributes (species richness, agricultural diversity, efficiency, harvest index, productivity, nutrient cycling, throughput, standing biomass, production/biomass, biomass/throughput, and agroecosystem nutrient balance) and economic properties (gross margin and returns to labour) for each farm. The comparative analysis suggests that what we perceive as ecologically sound farming, i.e. diverse and integrated natural resources management, can indeed be productive, profitable, and manageable, given access to labour and secure tenure. This type of analytical framework can help operationalise the sustainability concept. (C) 1997 Published by Elsevier Science Ltd.