Articles
Experimental assessment of irrigation efficiency over the dominant (flood and drip) irrigated crops in the Haouz plain, center of Morocco
Article number
1422_34
Pages
275 – 282
Language
English
Abstract
In the context of climate change, with reduced water resources in North Africa, the specific objective of this study was to assess the current irrigation methods (flood and drip) practiced by the farmers, via determining the water losses through deep percolation and soil evaporation.
This assessment was performed over the dominant crops (wheat, olive, citrus and apricot) in the Haouz plain (center of Morocco). From 2002 to 2018, 21 intensive experiments were conducted where the different components of water balance in the continuum soil-plant were measured.
Crop evapotranspiration (ETec), plant transpiration (Tsf) and rainfall (P) were recorded by eddy-covariance systems, sap flow systems and automatic weather station respectively, whereas the irrigation water amounts (I) were either measured or provided by the farmers.
The soil water balance method was adopted to evaluate the irrigation efficiency.
Water losses by evaporation reached 28% of water inputs in flood irrigation, notably lower (about 18-23%) with drip irrigation.
However, percolation losses in drip irrigation were surprisingly high; ranging between 29 and 41% of water inputs, whereas the values were relatively lower for flood irrigation ranging between 26 and 31%. The deep percolation values in the drip irrigation sites were high along crop development, reaching 18 and 32 mm week‑1 during dry and wet periods, respectively, what represented 37 and 50% of the water supplied, respectively.
In the flood irrigation sites, irrigation events were not always adequate, in quantity and/or timing, especially in summer when the potential evapotranspiration is very high.
For these sites, significant deep percolation occurred only during the irrigation days, with an average of about 22 mm week‑1 with irrigation event.
This study revealed that even by adopting water saving technologies such as drip irrigation, irrigation efficiency was not necessarily improved.
More efforts should focus on farmers training on optimal irrigation scheduling methods.
This assessment was performed over the dominant crops (wheat, olive, citrus and apricot) in the Haouz plain (center of Morocco). From 2002 to 2018, 21 intensive experiments were conducted where the different components of water balance in the continuum soil-plant were measured.
Crop evapotranspiration (ETec), plant transpiration (Tsf) and rainfall (P) were recorded by eddy-covariance systems, sap flow systems and automatic weather station respectively, whereas the irrigation water amounts (I) were either measured or provided by the farmers.
The soil water balance method was adopted to evaluate the irrigation efficiency.
Water losses by evaporation reached 28% of water inputs in flood irrigation, notably lower (about 18-23%) with drip irrigation.
However, percolation losses in drip irrigation were surprisingly high; ranging between 29 and 41% of water inputs, whereas the values were relatively lower for flood irrigation ranging between 26 and 31%. The deep percolation values in the drip irrigation sites were high along crop development, reaching 18 and 32 mm week‑1 during dry and wet periods, respectively, what represented 37 and 50% of the water supplied, respectively.
In the flood irrigation sites, irrigation events were not always adequate, in quantity and/or timing, especially in summer when the potential evapotranspiration is very high.
For these sites, significant deep percolation occurred only during the irrigation days, with an average of about 22 mm week‑1 with irrigation event.
This study revealed that even by adopting water saving technologies such as drip irrigation, irrigation efficiency was not necessarily improved.
More efforts should focus on farmers training on optimal irrigation scheduling methods.
Publication
Authors
S. Khabba, S. Er-Raki, J. Ezzahar, O. Merlin, M.H. Kharrou, A. Chehbouni
Keywords
climate change adaptation, percolation, evaporation, semi-arid area, water management
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