ECONOMIC FEASIBILITY AND BIOLOGICAL PRODUCTIVITY OF COCONUT-BASED AGROFORESTRY MODELS IN SRI LANKA

This study evaluates the economic feasibility and biological productivity of coconut-based agroforestry models designed for coconut smallholders. Coconut Research Institute of Sri Lanka has developed and established twenty-six agroforestry models in farmers' fields. Of them, four models were selected for this study. They were: mixed farming for Wet Zone (model 1), mixed cropping for Wet Zone (model 2), mixed farming for Wet Intermediate Zone (model 3) and catch cropping in young replanted coconut for Wet Intermediate Zone (model 4), established at Gaspe, Hanchapola, Katuneriya and Thulawala, respectively. Input and output data for several years, for each model, were used in the evaluation. Annual Gross Margins (GM) payback period, Net Present Value (NPV) and Benefit-Cost Ratio (BCR) were employed for the economic analysis. Biological productivity of the models was. determined employing Land Equivalent Ratio (LER) and Relative Yield Total (RYT). NPVs of agroforestry models were higher than the monocrop, suggesting the higher net worth of the agroforestry models in the long run. Other economic indicators also showed that agroforestry models were more profitable than coconut monoculture. In all models, LER exceeded unity, indicating the yield advantage with agroforestry over coconut monocultures. However, RYT values indicated that there were negative interactions between component crops of certain models, which can be attributed to the competition that occurs between crops