Seed Cotton Yield, Uptake of NPK and Economics of Bt Cotton (Gossypium hirsutum L.) as Influenced by Different Bio-fertilizers and In-situ Green Manuring under Irrigation

A field experiment was carried out during kharif season of 2009–2010 at the Agriculture College Farm, Raichur, Karnataka (India) to study the response of Bt cotton to different fertilizer levels, bio-fertilizers and in-situ green manuring under irrigation. The results revealed that among green manures sunnhemp in-situ green manuring registered significantly higher seed cotton yield, gross returns, net returns and benefit cost ratio (B: C ratio) (2231 kg ha⁻¹, Rs. 60,246/ha, Rs. 35,189/ha and 2.40, respectively). With respect to uptake of NPK application of sunnhemp in-situ green manuring found significantly Higher N (128.27 kg ha⁻¹), P (30.63 kg ha⁻¹) and K (142.33 kg ha⁻¹) over no green manuring. Among different Fertilizer levels and Bio-fertilizers, 150% recommended dose of fertilizers (RDF) recorded significantly higher seed cotton yield per hectare, gross returns, net returns and B: C ratio (2295.78 kg ha⁻¹, Rs. 61,986/ha, Rs. 36,473/ha and 2.42, respectively). With respect to uptake of NPK application of 150% RDF found significantly higher N (132.46 kg ha⁻¹), P (32.44 kg ha⁻¹) and K (147.21 kg ha⁻¹)