Spatial and temporal variations in evapotranspiration and net water requirements of typical Mediterranean crops on the island of Cyprus

Abstract

SUMMARYDiminishing irrigation water availability and increased crop evapotranspiration (ET) have already been shown to pose threats to agricultural productivity. The aim of the current study was to estimate the values and trends of both ET and net irrigation requirements (NIR) of those crops consuming most water due to the size of their cultivated area (citrus and potatoes) in a water-scarce region with typical Mediterranean climate, such as Cyprus, analyse possible spatial and temporal variations of these parameters, and discuss implications of this analysis on agricultural water conservation. A linear regression analysis of ET and NIR values of potatoes and citrus during recent decades in their four main cultivated areas uncovered both increasing and decreasing trends for these parameters. Overall, however, the results did not show any change in irrigation water demands for these crops during recent years. In accordance with this outcome, average ET and NIR values of the majority of cultivated crops on the island showed no statistically significant differences between the periods 1976–2000 and 1990–2014. Conversely, this was not the case when data were analysed within each weather station across crops. It is suggested, therefore, that agricultural water resource management schemes should not be focused merely on a regional analysis of changes but that emphasis should be given to site-specific values and trends of ET and NIR estimations, ultimately serving the conservation of agricultural water.