TOWARDS SUSTAINABLE IRRIGATION WATER BY USING DIFFERENT POLYMER RATES WITH DEFICIT IRRIGATION LEVELS: CASE STUDY IN EGYPT

ABSTRACT
The concern of water scarcity and its high usage in agriculture has become a pressing issue. To address this issue, new techniques and ideas must be implemented to conserve water in agricultural production systems. One method that can be used to conserve water is the application of soil conditions management. An experiment was conducted to study the effect of different deficit irrigation regimes and levels of polymers and nitrogen on water use efficiency (WUE), nitrogen use efficiency (NUE), yield, yield components, and sugar beet cultivars' physiology. The study was carried out on sandy soil using a drip irrigation system, and it was designed in a split-plot format. The experiment included 15 treatments, which consisted of three deficit irrigation levels and five polymer treatments per level: P1 (control), P2 (30 kg/fed polymer), P3 (30 kg/fed polymer and 30 kg/fed nitrogen), P4 (60 kg/fed polymer), and P3 (60 kg/fed polymer and 60 kg/fed nitrogen) with three replicates. The results showed that the highest values of WUE were achieved in both seasons when using 70% deficit irrigation with polymer treatments P2, P3, and P5. Additionally, the second season with 85% deficit irrigation with polymer treatments P2, P3, and P5 also had a similar effect on WUE values. The highest values of WUE and NUE were achieved when using 70% deficit irrigation with polymer treatment P5 in the second season. These values were 14.3 and 293.6 kg/m³ for WUE and NUE, respectively. The use of deficit irrigation, polymers, and nitrogen had a positive impact on the water and nitrogen use efficiency of sugar beet cultivars, which ultimately led to an increase in yield and overall productivity. However, further research is needed to fully understand the limitations and implications of these techniques. It is also important to consider the economic and environmental costs and benefits of these methods before implementing them on a larger scale.