عنوان مقاله [English]
Drought in Iran is a climatic fact, and due to the growing demand for various parts of the water, the problem of water scarcity will become more acute in the coming years. Due to lack of water and for proper use of water resources, the importance of research on wheat irrigation by drip irrigation technique, has been increased in recent years. This study was carried out to investigate the effect of distance between drip lateral and amount of irrigation water on wheat water productivity in drip irrigation (tape) in two farms located in Mashhad (MHD) and Torbat-e-Heydariyeh(Rokh) (RKH) with Loam and clay loam soil texture respectively, were in the 96-95 crop year. The statistics design was complete blocks (factorial) and consisted of three lateral spacing (D1: spacing of 50 cm, D2: spacing of 75cm and D3: spacing of 100cm). The amount of irrigation water was also in three treatments (W1: 100%, W2: 75% and W3:50% of irrigation water requirement). The results showed that irrigation water treatment had significant effect on grain yield in both areas of the project and the highest yield was obtained from W1 treatment by 7537 and 5342 kg/ha in Mashhad and Torbat-e-Heydariyeh, respectively. Irrigation Lateral spacing also had significant effect on grain yield in both region and the highest yield was obtained from D1 treatment (7267 and 5920 kg/ha in Mashhad and Torbat-Heydariyeh, respectively). Interaction of irrigation water and Irrigation Lateral spacing (W-D) on water productivity in Mashhad region was insignificant but significant in Torbat-e-Heydariyeh region. The interaction showed that the best water productivity (1.72 and 1.52 kg/m3 in Mashhad and Torbat-e-Heydariyeh, respectively) was obtained in W3D1 treatment. Although W1D1 treatment (50 cm lateral spacing and 100% irrigation water) had the highest yield (8167 and 6104 kg/ha, respectively), they were in the c group in terms of productivity with W2D2 and W3D3 treatments.