Effects of Planting Method and Integrated Nutrient Management on Growth, Yield and Yield Components of Onion (Allium cepa L.) in Chiro District, West Hararghe, Ethiopia

Farmers of Hararghe highland practice rain-fed onion cultivation, which is suffering from poor soil fertility caused by undulating topography that is prone to erosion and sub-optimal use chemical fertilizers resulted for low yields of crop. Hence, the experiment was conducted during 2022 main cropping season at OdaBultum University, West Hararghe Zone, Ethiopia. The experiment consisted six levels of nutrients (control, 100% recommended fertilizer (RDF), 2.5 and 5 t ha-1 Vermicompost combined with 50% or 75% RDF) and three methods of planting (flat, raised and ridge-furrow). The treatment combinations were arranged using split plot design by considering planting method as main plot and the fertilizers as subplot. The highest leaf length (47.63 cm), bulb diameter (6.2 cm), bulb length (7.072 cm), marketable yield (27.12 t ha-1) and total bulb yield (28.59 t ha-1) were recorded from ridge-furrow. Similarly, longest leaf (46.33 cm), bulb diameter (6.1cm) and marketable yield (27.64 t ha-1) were recorded from plants that received 5 t ha-1Vermicompost and 50% RDF. The highest adjusted marketable bulb yield (24.4 t ha-1) and highest net benefit (329632.6 Birr) with acceptable Marginal rate of return (MRR) (883.65%) was obtained from ridge-furrow whereas net benefit 260987.37Birr with 9537.36% MRR was also obtained from integration of 5 t ha-1Vermicompost plus 50% RDF. Thus, it is inferred that ridge-furrow planting method with application of 5 t ha-1 VC and 50% RDF seems be appropriate for Bombay Red onion producing farmers in the studied area as well as other areas having similar agro-ecologies.