Water scarcity is of growing concern in many countries around the world, especially within the arid and
semi-arid zones. Accordingly, rationalizing irrigation water has become an obligation to achieve the sustainable
developmental goals of these countries. This may take place via using deficit irrigation which is
long thought to be an effective strategy to save and improve water productivity. The current study is a
trial to evaluate the pros and cons of using 50 and 75 % of the irrigation requirements (IR) of wheat (deficit
irrigations) versus 100 %IR, while precisely charting changes in wheat growth parameters, antioxidant
enzymes in plant shoots and the overall nutritional status of plants (NPK contents). Accordingly, a field
experiment was conducted for two successive seasons, followed a split-plot design in which deficit irrigations
(two irrigations to achieve 50 % of the irrigations requirements (IR), three irrigations to attain
75 % IR, and four irrigations to fulfill 100 % IR) were placed in main plots while four different studied
wheat cultivars were in subplots. Results obtained herein indicate that deficit irrigations led to significant
reductions in growth parameters and productivity of all wheat cultivars, especially when using 50 % IR. It
also decreased NPK contents within plant shoots while elevated their contents of proline, peroxidase, and
catalase enzymes. On the other hand, this type of irrigation decreased virtual water content (VWC, the
amount of water used in production on ton of wheat grains). Stress tolerance index (STI), and financial
revenues per unit area were also assessed. The obtained values of grain productivity, STI, VWC and financial
revenues were weighted via PCA analyses, and then introduced in a novel model to estimate the efficiency
of deficit irrigations (ODEI) whose results specified that the overall efficiency decreased as follows:
50 %IR < 75 %IR < 100 %IR. In conclusion, deficit irrigation is not deemed appropriate for rationalizing irrigation
water while growing wheat on arid soils. |
