Nutrient uptake and yield of onion as influenced by chemical fertilizer and organic manure

Field experiments were carried out during the rabi seasons of 1997–98, 1998–99 and 1999–2000 in Chhiata series of the Grey Terrace Soil (Albaquepts) to find out the effects of different chemical fertilizers (N, P, K, S, Zn) and organic manure on yield, yield attributes and nutrients uptake by onion (cv. Taherpuri) under irrigated condition. Application of N, P, K, S and Zn showed significant influence on nutrient uptake, yield and yield attributes of onion. Addition of organic manure only also improved nutrient uptake and bulb yield. Uptake of nutrients by leaf increased up to 70 DAT and thereafter declined while bulb accumulated nutrients up to DAT. Significantly highest bulb yield, maximum net return and benefit cost ratio were obtained by applying 100 kg N, 100 kg P₂O₅ 100kg K₂O, 20 kg S and 5 kg Zn/ha. The lowest bulb yield, net return and benefit cost ratio were recorded when the plot received zero fertilization (control).