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 our 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. Hence, farm surveys, regarding the cropping years 2003 and 2007, were carried out. We have assessed the technology performance using the Data Envelopment Analysis approach and we have computed the Malmquist index in order to characterize the productivity change. Our empirical findings showed that the technical efficiency of the farms has increased by 17% during this period leading to an improvement of the water use efficiency up to 22%. Both, the technical efficiency change as well as the technical change have contributed to this improvement. However, the farmers have to enhance further their irrigated practices in order to save more water. Indeed, in 2007, the water use efficiency was only 78%.