Agrobiodiversity Enhancement for the sustainability of the tropical uplands: An evaluation of agricultural land use in Liliw, Laguna, Philippines

摘要

Agrobiodiversity Enhancement (ABDE) is a strategy that has been advanced for preventing environmental degradation without losing agricultural productivity. However, there is not yet sufficient evidence to support the important role that ABDE might have for managing agricultural land use in the tropical uplands. This research is an attempt to help fill this knowledge gap. The general aim of the thesis was to explore the potential of ABDE as a management alternative for agricultural land use in the uplands in terms of environmental protection, productivity and farmer acceptability. To achieve the aim, a methodological framework for evaluating agricultural land use in the uplands was developed. The methodology aimed at allowing one to understand the influence of agricultural land use on natural resources and farm productivity and the social factors that will most likely influence land users to enhance agrobiodiversity of their production. The methodological framework provided a minimum set of criteria and indicators that can be used for assessing agricultural land uses in the uplands. Main criteria for the evaluation included protection, productivity, viability security and acceptability. The following indicators were included: Shannon Diversity Index, Depth of Topsoil, Soil Organic Matter, Soil Nitrate, Crop Yields, Net Income, Trend in Income and Harvest Loss, Farmer Traits, Farm Characteristics and Farmer perceptions on the influence of farming on the health of natural resources and of the farm workers. The methodological framework also includes a range of methods and techniques for gathering environmental, economic and social data in the uplands and indicates circumstances under which each might best be utilized. Using the methodological framework, agricultural land use in an upland area in Liliw, Laguna Philippines was evaluated for protection of natural resources, specifically of the soil quality and for farm productivity and for the social factors that influence the way agricultural lands are managed. Results showed integration of horticultural trees and crops have potential for protecting thickness of the topsoil, reducing nutrient wastage and is more economically profitable than monocropping systems. Specifically, coconut exhibited importance in maintaining thickness of topsoil while lanzones played major role in augmenting farm income and as buffer to income losses from annual crops. Older farmers and women were found associated with agricultural land use with diversified production in the case study area. The Logit model analysis further showed that leadership quality and land ownership are the social factors that will likely influence integration of horticultural trees and crops in the uplands. Other personal characteristics like years of experience in farming, access to other sources of livelihood, land size, awareness of land degradation and effect of agrochemicals on heath of the farm workers have no likely influence on agricultural lands with integration of horticultural trees and crops. SWOT analysis of agricultural land use in the case study site showed that despite the environmental and economic advantages of agricultural lands with diversified production, there are weaknesses and barriers to its further development and implementation. From this assessment, implications for developing and implementing an ABDE intervention program for the tropical uplands were drawn.