Water is a very limited resource in Tunisia, both in quantity and in quality. Problems of quality are related to urban, industrial and agricultural activity. Erosion is causing dams to silt up and is leading to phosphorus accumulation in water. The use of agrochemicals, primarily nitrogen and phosphorus, is causing problems of eutrophication. This paper presents the results of a study of sediment and nitrate pollution. The methodology used is based on the EPIC simulation model and a multi‐objective programming model (MOPM). The data generated by EPIC are input for the MOPM together with the economic variables. These tools are applied to a 486 ha farm located in northern Tunisia which includes an irrigated area of 300 ha. The study considers three objectives: maximization of gross margin, minimization of erosion, and minimization of nitrate losses. The non‐inferior set estimation method is implemented to generate the trade‐off curves between the objectives. Results show that nitrate losses are important for both rainfed and irrigated land. The same conclusion is valid for erosion. It is shown that the farmer can reduce the environmental burden without decreasing gross margin, since he is operating below the efficiency curve.
[1]
Slim Zekri,et al.
On-farm costs of reducing nitrogen pollution through BMP
,
1993
.
[2]
J. Brian Hardaker,et al.
The role of modelling in the quest for sustainable farming systems
,
1995
.
[3]
G. Flichman,et al.
Agricultural policy and technological choice: a regional analysis of income variation, soil use and environmental effects under uncertainty and market imperfections.
,
1995
.
[4]
J. Cohon,et al.
Generating multiobjective trade-offs: an algorithm for bicriterion problems
,
1979
.
[5]
Carlos Romero,et al.
Multiple Criteria Analysis for Agricultural Decisions
,
1989
.
[6]
Daniel J. Bernardo,et al.
Farm-Level Economic Analysis Incorporating Stochastic Environmental Risk Assessment
,
1995
.
[7]
P. Yu.
A Class of Solutions for Group Decision Problems
,
1973
.