Authors: Reda Khaled Darwesh
A FIELD experiment was conducted in the two successive winter seasons ( 2016-17 and 2017-18) to investigate the impact of cultivation method; dry cultivation ( dry seed on dry soil) and traditional one (wet seed on wet soil) and irrigation regime; five different irrigation regimes as follows, irrigation till 5 cm above soil surface, (traditional, I1), using soil moisture depletion (I2), irrigation with 0.8 from pan evaporation (I3), irrigation with Hargreaves equation, 1981 (I4) and irrigation till 2.5 cm above soil surface (I5).
The obtained results showed that decreasing amount of irrigation water from traditional method (I1) to 2.5 cm above soil surface (I5) reduced fresh yield by 5.49 and 6.75 ton fed.-1 with water saving ≈14.5% (≈ 336.0 m3fed.-1,) for dry seeds cultivation method, and the corresponding values 4.87 and 7.34 ton fed.-1 with water saving 10.75% (≈ 280.0 m3fed.-1,) for wet cultivation one in the overall seasons. Meaningfully, an average of ≈ 700-840 million m3 water could be saved at the national level (≈2.5 million fed.). Moreover, mean reduction in dry yield by 24.62 kg fed.-1, (6.35 %) and 13.00 kg fed-1 (3.51 %) could be resulted from dry cultivation method, and by 36.45 kg fed-1 (8.68 %) and 10.91 kg fed-1 (2.60 %) could be resulted from wet cultivation method in the first and second seasons respectively.
The highest overall mean values of water consumptive use (CU) and consumptive use efficiency (Ecu, %) were recorded irrigation without any stress during the growing season (I1). Productivity of irrigation water (PIW kgm-3) and water productivity (WP kgm-3) for fresh yield was the highest values recorded under I5 (the lowest water consumed) for dry and wet cultivation methods.