ABSTRACT
Soil is a complex natural resource because it includes both stock and flow resources. Most of the soil's flow resources have a critical zone of exploitation, below which irreversible damage may occur. The "critical zone" is the range below which a decrease in flow, given existing technologies, cannot be reversed economically. Changes in institutions or economic factors may change the course of action taken by an individual farmer in favour of either conservation or depletion. Soil conservation projects, by changing the current and future characteristics of erosion, affect on-site and off-site economic activities. Economic analysis of any project involves dealing with time. Benefits and costs are distributed over time and measures of project worth are reduced using indicators of time dimensions. Soil erosion changes the quantity and quality of both inputs and outputs of different economic activities. Soil conservation programs potentially affect production factors and output markets. The potential effects are not unusual except for their influence on land markets.
