Application of deficit irrigation strategy for barley (Hordeum vulgare L.) and wheat (Triticum durum Desf.) in the region of Biskra

This study was carried out during the growing season 2013-2014 in order to determine the effect of deficit irrigation on grain and straw yield of barley and wheat, along with irrigation water use efficiency at grain yield (IWUEg) and total biomass (IWUEbio), using flood irrigation for clay loam to slit clay soil texture under the arid climate of Biskra. Three deficit irrigation strategies were applied: T1 (50% of full water supply, from initiation to heading), T2 (50% deficit during grain filling), T3 (alternate deficit during whole season). Different treatments were compared with T0 (full irrigation). The obtained results show that mean grain and straw yield forT1, T2and T3treatments of both crops, were significantly affected by deficit irrigation (P<0.005).The water deficit during grain filling (50% water supply) for both crops had a less impact on grain yield (11% and 15% for barley and wheat, respectively), saving 20.32% of water and improving both IWUEg and IWUEbio, compared to full irrigation supply (T0).The findings of this study support the idea that the most effective strategy of deficit irrigation is to improve IWUE, by reducing the amount of applied water during those growing phases which have less impact on the yield and growth.