(326d) Multi-Objective Optimization Applied to Sustainable Rain-Fed and Irrigated Crop Production: A Case Study of Wheat Production in Spain

Water scarcity is a major environmental problem worldwide with a large impact on the degradation of ecosystems and resources. Particularly, in arid and semiarid countries water consumption causes significant environmental impacts on natural resources, ecosystems and even human health. Most production systems create water shortages which affect natural systems and, in particular, the agricultural sector represents more than two-thirds of the global water use. In this backdrop, appropriate environmental strategies and policies are needed in the agricultural sector in order to achieve a more sustainable agricultural production system.

Previous works have concentrated on quantifying the environmental impact of water consumption. To achieve a more sustainable agricultural production system, however, it is necessary to integrate these descriptive metrics with tailored decision-making tools.

Optimization tools can assist decision-making in this area. In particular, multi-objective optimization is a well suited approach to address environmental issues when production objectives must be optimized without neglecting the environmental concerns. Particularly, the combined use of multi-objective optimization techniques and life cycle assessment principles is a useful tool for guiding the search towards more sustainable agriculture patterns.

This paper presents a systematic multi-objective optimization tool for optimizing rain-fed and irrigated areas considering economic and environmental criteria. Our tool is based on a linear programming model that integrates water footprint data and life cycle assessment principles. The water footprint methodology estimates the crop water requirements for green, blue and grey water in a specific location, while the life cycle assessment methodology determines the potential environmental impact on ecosystems and resources. The solution of the multi-objective linear programming model developed is given by a set of optimal Pareto alternatives, each showing a unique combination of objectives values and entailing specific optimal rain-fed and irrigated cropping areas.

The capabilities of the proposed approach have been demonstrated through its application to a real case study of wheat (Triticum aestivum L.) production in Spain. Results show that significant reductions in the damage to ecosystems and resources can be attained while still maintaining or even increasing the wheat production by an adequate distribution of the rain-fed and irrigated wheat areas in the Spanish watersheds. Moreover, some of the Pareto solutions found, each one entailing specific optimal crop areas in each watershed, improve the current situation simultaneously in the two objectives considered. From the set of Pareto solutions, decision and policy makers should select the best one according to their economic and environmental preferences and considering the views of the farmers and stakeholders (social concerns). Therefore, these optimal solutions represent a useful guide to define appropriate strategies and policies that will ensure a more sustainable agriculture system, minimize the environmental damage and ensure food security.