Effect of Intra-Row Spacing and Rates of Organic and Inorganic Fertilizers on Yield and Yield of components of Irrigated Onion in Northern Ethiopia By

Abstract

A field experiment was conducted with the objective of investigating response of rates of organic(FYM) and inorganic (NPS) fertilizers and intra-row spacing on yield, yield components and nutrient uptake of Bombay red onion (Allium cepa L.) variety under irrigation condition at Felegdaero village, Mekelle in Tigray. The experiment was carried out in the offseason of 2024 at farmer’s field on Cambisols. The experiment was laid down in a Randomized Complete Block Design (RCBD) in factorial arrangement with three replications. The treatments applied were combinations of six levels of fertilizers (control (0), 50% FYM + 50% NPS, 25% FYM + 75% NPS, 75% FYM + 25% NPS, and 100% FYM + 0% NPS) and three levels of spacing (8 cm, 10 cm and 12 cm). Soil, agronomic and nutrient uptake data were collected and analyzed. The result of the study showed that bulb dry weight, marketable yield, total yield, biomass yield and harvest index of onion were significantly affected by the main effects and interactions of intrarow spacing and fertilizer applications and spacing levels. The maximum marketable and total biological yield of onion (27.500 t/ha) and (29.398t/ha) and 31806kg//ha were obtained from the main effect of 50% FYM + 50% NPS fertilizer at 10cm intra- row-spacing, while the minimum marketable and total yield of onion (18.796t/ha) and (23.981t/ha) were obtained from the control plot at spacing of 8cm. . The study also showed that the onion N, P and S uptake were significantly (P < 0.001) influenced by the main effect of FYM and NPS fertilizer rates and spacing. The optimum (170, 23.32 and 2001kg/ha) N, P, S uptake were recorded from plots that received 7.5t /ha-1 FYM and 123.3 kg/ha NPS fertilizer rates whereas, the lowest (118.3, 14.64 and 2284 kg/ha) N, P and S uptake were obtained from the unfertilized plots, respectively. Applications of FYM and NPS fertilizers at the rate of 7.5t /ha-1 FYM and 123.3 kg/ha at intra-row spacing of 10cm were economically feasible. Therefore, 7.5t /ha-1 FYM and 123.3 kg/ha NPS fertilizer rate at intrarow spacing at 10 cm should be recommended for Bombay red onion variety on Cambisols for Felegdaero village and other similar areas in Mekelle area.