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.

Irrigation Groundwater Quality Characteristics: A Case Study of Cyprus

“…However, adverse climatic conditions and lack of adequate soil moisture causing failures during transplanting led to an abandonment of crops [36]. Locally, irrigation requirements are calculated based on a Class A evaporation-pan methodology adopted from Cyprus Agricultural Research Institute [37] following Allen et al [38]. For example, the mean yearly evapotranspiration rate (i.e., crop water requirements) for high water-demanding crops such as bananas is estimated at 1255 mm, for citrus it is 846 mm and for olive trees (which is considered a low water-demanding crop) it is 430 mm.…”

Trees and Crops Arrangement in the Agroforestry System Based on Slope Units to Control Landslide Reactivation on Volcanic Foot Slopes in Java, Indonesia

“…Due to the extremely high soil water content, the depositional zones need to be controlled with plants that minimize the intensity of gully erosion, soil cracks, landslides, and soil creeps [55]. The high water content can be maintained by cultivating high water consumption plants such as bamboo [56][57][58], banana [59,60], sugar palm [61,62], and coconut [63]. They can be planted at the lowest elevation of the depositional zone and can be combined with the recommended crop choices for erosional zones.…”

Irrigation of Greenhouse Crops

“…Regarding the pan A coefficient, a constant value of 0.79 provides a good estimation of reference evapotranspiration (ET O ) rates in plastic greenhouses under Mediterranean conditions [119], while Çakir et al [57], working with cucumber in a solar greenhouse covered with netting material, indicated a plant-pan coefficient between 1.25 to 1.50. In line with this, for several crops in Cyprus, the evapotranspiration rate was calculated from reference evapotranspiration based on pan evaporation data, following the methodology proposed by Allen et al [118] as indicated in Table 3 derived from Markou and Papadavid and Christou et al [120,121]: Table 3. Monthly and yearly estimated evapotranspiration requirements for several crops in protected cultivation (mm).…”