Length : around 15 minutes
You are going to enrich the initial model primal1.gms – (which you wrote in lesson 7, download it from the Model Library) by taking into account different production technologies. Run the primal1.gms model and save it under the name technique1.gms. Modify it so as to take into account the new crop (tomato), and two new production technologies (extensive and intensive).
« A given farm can grow three types of crop, wheat, maize and tomato, and use two different crop practices, extensive and intensive. The area to be cultivated and technology to be used must be determined, knowing that :
The objective of the farmer is to maximize his income.
Labour needs are as follows :
| Labour needs (h/ha) | ||
| Technology | Extensive | Intensive |
| Wheat | 15 | 25 |
| Maize | 45 | 50 |
| Tomato | 80 | 100 |
Yields and costs are as follows :
| Yield (ton/ha) | Cost (€/ha) | |||
| Technology | Extensive | Intensive | Extensive | Intensive |
| Wheat | 4.5 | 5.0 | 250 | 300 |
| Maize | 8.0 | 10.0 | 400 | 500 |
| Tomato | 13.0 | 16.0 | 1200 | 1350 |
The selling price of wheat is 150€/ton, that of maize is 150€/ton, and that of tomato 185€/ton.
The farm area is 50 ha, and the farmer can work 2000 hours a year. »
What cropping pattern is chosen, and what is the optimum income for the farmer ?
Then check the solution :
