A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1995

Land resources are finite and with limited area suitable for agricultural production. However, with the increasing demand for food and other agricultural commodities, subsistence farmers are left with no option but to cultivate on marginal agricultural lands where productivity is relatively low. Moreover, the traditional methods of farming have aggravated the degradation of the already poor resource base. Unless efforts are directed towards the development of marginal agricultural lands, the vicious cycle of poverty and land degradation will continue to enslave the poor sector of the society that are most dependent on natural resources. The development of marginal agricultural lands requires a thorough analysis of the socio-economic and bio-physical characteristics of the farming environment. This is achieve by integrating land evaluation (LE) and farming systems analysis (FSA). In this approach, FSA contributes to the selection and description of land use systems that are relevant to small farmers on marginal land. On the other hand, LE contribute to the development of the area by ascertaining the alternative land use systems for a particular marginal land and allowing comparison between actual and potential uses. The very diverse and complex processes involved in FSA and LE were facilitated through a Geographic lnformation System (GIS). Using the spatial modeling capabilities of a GIS, spatial decision models of farming systems, expressed in the form of production systems, were generated. These models assign the proper crop to each parcel on the basis of its biophysical suitability, crop rotation as specified technical and management priorities to derive an actual operational plan that meets the objectives of development. Analysis on the socio-economic and bio-physical conditions of the southern Cebu municipalities of Alcoy, Boljoon and Oslob (ABO) revealed some constraints to the development of marginal agricultural lands. These include unfavorable rainfall patters, insecurity of land tenure, poor socio-economic conditions of farmers, poor marketing infrastructure, and degraded land resource base. The most common physical limitations in ABO are steep slopes, shallow soils and severe erosion. The spatial decision models of different production enterprises revealed that only a small portion of the total land area are moderately to highly suitable. The analysis, however, indicated that the development of agroforestry and pasture-livestock production systems could be promoted successfully. It was found out that any sustainable production systems should be based on sound soil and water conservation practices. Comparison between the actual and the potential use of the land revealed that com is grown on better and more suitable locations than coconut. This analysis gave a conclusion that com remains to be the central basis of land use allocations among farmers in the area.