Abstract

                                Field experiments were conducted to work out the physical and economic optimum of NPK fertilizers required for groundnut by using empirical model. The experiment was conducted in Randomized Block Design (RBD) with different NPK levels viz., Control, 25 % Recommended Dose of Fertilizers (RDF) (4:9:14 kg NPK ha-1 ), 50 % RDF (9:17:27 kg NPK ha-1 ), 75 % RDF (13:26:41 kg NPK ha-1 ), 100 % RDF (17:34:54 kg NPK ha-1 ), 125 % RDF (21:43:68 kg NPK ha-1 ), 150 % RDF (26:51:81 kg NPK ha -1 ), 175 % RDF (30:60:95 kg NPK ha-1 ) and 200 % RDF (34:68:108 kg NPK ha -1 ). The experiments were conducted during rabi 2006-’07 and kharif 2007. The results revealed that among the different levels of NPK studied, application of 175 per cent recommended dose of fertilizers (30:60:95 kg NPK ha -1 ) registered significantly higher growth characters, yield parameters, yield and economic returns. The response model worked for different levels of NPK during rabi 2006-07 and kharif 2007 seasons indicated that the physical optimum levels for groundnut was 33.9 kg N, 67.5 kg P2 O5 and 107.3 kg K2 O ha-1 , whereas the economic optimum was worked out to be 33.7 kg N, 65.8 kg P 2 O 5 and 105.5 kg K 2 O ha -1 .

Key words : Response model, groundnut, NPK