Rice cultivation adaption to water resources shortage in Egypt

Climate change and water resources shortage in Egypt has placed the responsibility on the researchers in the agricultural field to find practical solutions that would confront the environmental constraints that the strategic crops are exposed to them. These solutions are such as creating new varieties that can withstand high temperatures and irrigation water shortages, or adding materials that raise plant resistance to any environmental stress. Egypt's rice cultivation required a large amount of the water budget of Egypt. So, two field experiments on rice cultivation were carried out aiming to assess three irrigation water levels [100% of traditional followed full irrigation (TFI) in most of the delta regions (equivalent 16000 m3 ha-1), 80% of TFI (equivalent 12800 m3 ha-1) and 60 % of TFI (equivalent 9600 m3 ha-1)] as main plots. While the sub-main plots were assigned by two treatments of DM (applied at a rate of 20.0 Mg ha-1 or not), where Mg ʺmega gramʺ=106 g i.e., metric ton. DM=mixture of zeolite, biochar and rice straw compost (at a ratio of 3.0 zeolite: 1.0 biochar: 7.0 compost). Also, the foliar application of anti-transpirants [kaolin (7%) and magnesium silicate (7%) with a volume of 1300 L ha-1plus control (without)] were allocated in the sub-sub plots. The main results showed that treatments of 80 and 60 % of TFI caused a raise in the production of enzymatic antioxidants i.e., superoxide dismutase (SOD) and peroxidase enzyme (POD). While the DM addition and both anti-transpirants led to a decline in the values of SOD and POD. The deficit irrigation treatments (80 and 60 % of TFI, respectively) caused a significant decline in the rice growth performance as well as the quantitative and qualitative yield (at the harvest stage) compared to the traditional irrigation (100 % of TFI). Regarding the DM treatment, the plant performance and productivity significantly increased with DM addition compared to the corresponding rice plants grown without DM addition. Concerning the exogenous applications, the best plant growth performance and productivity were realized with magnesium silicate followed by kaolin and lately control. On the other hand, the addition of DM increased the soil water holding capacity at the harvest stage compared to that of the initial soil. Also, it is worth observing that the addition of DM before rice cultivation under 80% of TFI with exogenous application of both anti-transpirants caused growth performance and productivity were better than that recorded with rice plants grown without both DM and anti-transpirants (control) under 100% of TFI. Generally, it can be concluded that DM treatment may hold enough amounts of both water and nutrients and release them as required by the rice plant. Also, anti-transpirants have great potential in raising the water-deficit stress tolerance of rice via increasing leaf reflectance and thereby reducing water loss through the transpiration process. Thus enhancing the growth performance, quantitative and qualitative yield of rice with the limited supply of irrigation water.