Nonparametric approach for measuring the productivity change and assessing the water use efficiency in the irrigated areas of Tunisia

In order to cope with the water scarcity, Tunisia has to manage efficiently the demand of the economic and social sectors mainly that of the agricultural irrigated activities. Within this context, this investigation aims to analyze the technical efficiency, the water use efficiency and the dynamic of the productivity of the irrigated areas in the Sidi Bouzid region. Farm surveys have been carried out during 2003 and 2007 harvesting years and technology performance has been assessed using Data Envelopment Analysis approach. Malmquist index has been also computed in order to characterize the productivity change. Empirical findings showed that the technical efficiency of the farms has increased by 19% during this period leading to an improvement of the water use efficiency up to 24%. Both, the technical efficiency change as well as the technical change reveal a positive impact on the productivity change. However, in 2007, the water use efficiency was only 79%. Therefore, farmers have to improve further their irrigated practices in order to save more water.