Research Article
Bekele T and Abebo M
Abstract
Agricultural water is scarce in many parts of the world and becoming a global agenda. It is the largest among sectors which are consuming huge fresh water. This experiment was carried out for three years to investigate the yield and water productivity of onion under different deficit irrigation levels. The method used was field experiment contains combination of five treatments (100% ETc throughout the season, 85% of ETc throughout the season, 70% of ETc throughout the season, 50% of ETc throughout the season and farmers practice laid out in randomized complete block design (RCBD) with three replications. The combined yield results showed that maximum yield was obtained from 100% ETc (26.44 t/ha) and minimum yield was obtained from 50% of ETc (18.5 t/ha). Among treatments 100% ETc, 85% of ETc, 70% of ETc and farmers practice, there was insignificant yield difference with minimum yield reduction. But the treatment 50% of ETc had the significant yield difference with 100% ETc and 85% ETc. Maximum and minimum water productivity was obtained from 50% of ETc (7.8 kg/m3) and farmers practice (3.877.8 kg/m3), respectively. Water productivity of 85% of ETc (6.24 kg/m3) was greater than 100% ETc (5.56 kg/m3). The result of economic analysis indicated that Irrigating 85% of ETc earns best marginal rate of return next to 70% of ETc. From these result it can be concluded that in water scarce area using 85% of ETc provides a better yield, Water productivity and earns better income.