Agricultural water management for resilient farming: experimental insights into quality, water productivity, and profitability in water-scarce region of Southern Ethiopia
摘要
To cope with a scarce water supply, deficit irrigation is an important tool for reducing irrigation water use and increasing water productivity (Wp) under scarce water resource conditions. This experiment was conducted over the last three years (2018–2020) in the Arba Minch area of Southern Ethiopia. The main objective of the study is examining the level of deficit irrigation on onion yield, quality, WP and economic return without significantly reducing the yield of onion. The experiment laid in a randomized completed block design (RCBD) with five replications to investigate deficit irrigation techniques. Four levels of deficit irrigation water levels (100% of ETc, 85% of ETc, 75% of ETc, and 50% ETc) were used for investigation. Analysis of variance (ANOVA) showed treatments has significant variability in marketable yield, total yield and Wp in three consecutive years along with onion bulb quality parameters. The maximum marketable yield and total yield along with WP values were achieved through 100% of the ETc in all successive years followed 85% of the ETc. The combination of analysis showed 100% ETc deficit irrigation delivered the maximum yield results of 24.97 ton ha−1 marketable and 28.6 ton ha−1 total yield which did not differ significantly from 85% Etc deficit irrigation that yielded 22.13 ton ha−1 marketable and 26.86 ton ha−1 total yield respectively. Compared with the other levels of deficit irrigation, the highest combined WP of 4.445 kg m−3 was observed at 50% ETc (3.12 kg m−3, 3.02 kg m−3, and 4.27 kg m−3), with values ranging from 100%, 85% and 70%, respectively. In view of the economic return, 100% Etc had the highest net benefit of 208008 Birr/ha, followed by 198558 Birr/ha, which was observed from 85% of ETc without significant economic return, whereas the minimum (123858 Birr/ha gained from 50% ETc. Based on these findings, 85% ETc of irrigation application under the moisture stress area of Arba Minch should be applied to save water, improve bulb quality, increase the economic return for growers and increase the command area.