The study was carried out in Western Zahed Station in Tartous Research Center – the General Commission for Scientific Agricultural Researches during Agricultural seasons 2018- 2019- 2020, aiming to study the effect of drainage water and deficit irrigation on the productivity of Sorghum and Sesbania plants using three irrigation water qualities: pure water, mixed water (pure and drainage water) and drainage water, and three irrigation water quantities: full irrigation, 75% of full irrigation and 60% of full irrigation, the experiment was designed using Split plots design, the irrigation was applied when soil moisture was 80% of the field capacity in the full irrigation treatment and continued irrigation until the soil moisture reaching to the field capacity, irrigation water quantities was applied in the other treatments as 75% and 60% of water quantity in the full irrigation treatment, the drip irrigation method was used for irrigation, and seeds was planted on furrows for both Sorghum and Sesbania plants. The highest productivity of Sorghum was obtained in the drainage full irrigation treatment, with an average of (1.455) ton/ha, the drainage treatment was exceed the pure water and mixed water treatments by (0.066) ton/ha and (0.0277) ton/ha, respectively, and with significant differences at the comparison level of 5%, the same was for Sesbania as the drainage treatment full irrigation achieved the highest productivity with an average of (4.826) ton/ha, whereas, the drainage treatment was exceed the pure water and mixed water treatments by (0.672) ton/ha. and (0.243) ton/ha, respectively, with significant differences at the comparison level of 5%. The full irrigation treatment in Sorghum was exceed the deficit irrigation treatments of 75% and 60% by (0.082) ton/ha and (0.189) ton/ha, respectively, with significant differences at the comparison level of 5%, and the full irrigation treatment in Sesbania exceed 75% and 60% treatments by (0.433) ton/ha and (1.611) ton/ha, respectively, with significant differences at the comparison level of 5%. The drainage deficit irrigation 60% treatment achieved the highest efficiency of water use in the Sorghum plant, with an average of (0.410) kg/m3, and the deficit irrigation 60% treatment exceed full irrigation treatment with a rate of 43.6%, and exceed deficit irrigation 75% treatment with a rate of 13.4%, with significant differences at the comparison level 5%, while the drainage deficit irrigation 75% treatment achieved the highest water use efficiency in the sesbania plant, with an average of (1.241) kg/m3. The results showed that Sorghum is tolerant of deficit irrigation, as the crop response coefficient to deficit irrigation (Ky) was less than one in both deficit irrigation treatments of 75% and 60% in pure water, mixed water and drainage water treatments. The results also showed sesbania is tolerant of deficient irrigation for the plant mass, where the crop response coefficient to deficit irrigation (Ky) was less than one in both the deficit irrigation treatments of 75% and 60% in the three water quality treatments, while the crop response coefficient for deficit irrigation (Ky) was more than one in the deficit irrigation treatment of 60% for grain yield of sesbania with pure irrigation water and became less than one with mixed water and drainage water, meaning that irrigation with drainage water increased C tolerance of deficit irrigation.
|
Keywords: Sorghum, Sesbania, drainage water, pure water, deficit irrigation, productivity, water use efficiency, crop response coefficient to deficit irrigation.
|