Irrigation and Drainage Systems

, Volume 23, Issue 1, pp 1–10 | Cite as

Crop coefficient and evaptranspiration of onion at Awash Melkassa, Central Rift Valley of Ethiopia

  • Mengistu Bossie
  • Ketema Tilahun
  • Tilahun Hordofa


Improved water management through precise crop water requirement determination is needed to improve the efficiency of water use in agricultural production. As a result, appropriate irrigation scheduling which can lead to water saving, improvements in the yield and income can be designed. In this study, three non-weighing lysimeters having dimensions of 2 m × 1 m × 2 m were used to determine water requirement (ETc) and crop coefficient (Kc) of onion (Bombay Red cultivar). Reference crop evapotranspiration (ETo) was determined using weather data recorded at the site. The measured ETc values were 51.3 mm, 140.5 mm, 144.8 mm, and 53.9 mm during the initial, development, mid-season and late season growth stages respectively. Crop coefficient (Kc) values, calculated as ratio of ETc to ETo, were 0.47, 0.99, and 0.46 during the initial and mid-season stages and end of late season. Furthermore, third-order polynomials were fitted well to predict the crop coefficient values as functions of growing degree-days (GDD).


Awash Melkassa Crop coefficient Ethiopia Lysimeter Onion 


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Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Mengistu Bossie
    • 1
  • Ketema Tilahun
    • 2
  • Tilahun Hordofa
    • 3
  1. 1.Meki Agricultural OfficeMeki-ZewayEthiopia
  2. 2.Haramaya UniversityHaramayaEthiopia
  3. 3.Awash Melkassa Agricultural Research CenterNazarethEthiopia

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