Water use and technical efficiencies in private irrigated perimeters in South-Eastern of Tunisia

The purpose of this paper is to assess the technical efficiency (TE) and proposes a measure for irrigation water efficiency (IE) based on the concept of input-specific technical efficiency for a sample of 100 irrigators in Zeuss-Koutine region (South eastern Tunisia). In this paper, data envelopment analysis (DEA) is used to quantify TE and IE. A major finding of the study is that the irrigation systems are clearly inefficient. Under constants returns to scale (CRS) specification, the average technical efficiency of the sample was 64%. This implies that output level could be producing by saving 36% of (all) farm inputs. A similar pattern of scores was shown for IE; although in this case the average IE was even lower (47.8%) indicating that if farmers became more efficient using the technology currently available, the same level of output can be produced using the same level of other inputs but with, on average, 52.2% less water irrigation.