Effect of phosphorus enriched organic manures on yield and economics of onion crop in Vertisol

The experiment was conducted at Kalagi taluka in Kalaburagi district, which belongs to the Agro-Climatic Zone-2 (North Eastern Dry Zone) of Karnataka state. The experiment was laid out in split-plot design with three main plot treatments and seven sub-plot treatments. Application of P-enriched organic manures at different levels of P-fertilizers had significantly increased the bulb yield of onion. The highest bulb yield of onion (29.38 t ha-1) was obtained with the addition of P-enriched poultry manure @ 3 t ha-1 + 100% RDF-P which was found superior to all other treatments. The increase in yield over control (no organic manure) was 20.90% in onion crop. Addition of P-enriched poultry manure with 50 per cent RDF-P was found beneficial and yielded higher monetary returns (Rs.421454 ha-1) and B:C ratio (6.80) from onion crop production.