Deficit Irrigation Management as Strategy Under Conditions of Water Scarcity; Potential Application in North Sinai, Egypt

Water plays an essential role in yield productivity; however, in the near future it seems that many Arabian and African countries will suffer from water scarcity periods. Egypt, as one of the Arabian and African countries, reflects this phenomenon as a result of increases in population, economic activities, living standards, and cultivated land, as implemented by the plans of successive Egyptian governments. Total water withdrawal between 2010 and 2015 was 68.3 km³/year, which was distributed among agricultural, municipal, and industrial sectors. The agricultural sector is considered the main consumer as it is the core of the Egyptian economy; the agricultural sector consumed approximately 59 km³/year for irrigation purposes and other agricultural activities. With double cropping or two crops per year, intensive agriculture has doubled the water demand. In addition, loss of water by evapotranspiration from the cultivated lands is estimated to be 3 km³/year. In order to identify both the effects of reduced water supply on yield characteristics and water use efficiency (WUE) in newly reclaimed lands, we applied our experiments in North Sinai, which is one of the strategic lands planned for reclamation by the Egyptian government.

Three irrigation treatments were performed: 3,600m³/ha (W1), 6,000 m³/ha (W2), and 7,200 m³/ha (W3; normal and recommended irrigation dose) with water from the El-Salam canal, using faba bean (Vicia faba L.) as the dominant crop in this region. The obtained results revealed that a relative decrease in soil salinity, compared with the initial soil salinity, occurred in parallel with increasing water supply regimes, by an average of 33.0%, 37.4%, and 47.6% for W1, W2, and W3 respectively. The WUE showed another phenomenon. Using the W1 water regime with faba beans under saline soil situations saved approximately 50% of the added water and showed a higher WUE of 2.36 kg/m³ compared with W2 and W3, which resulted in WUE values of 1.75 kg/m³ and 1.39 kg/m³, respectively. Also, we produced a simulated yield model of the obtained yield with the field characteristics (R² of 0.98), and the model performance indicated a small root mean square error, of 0.12.