Effect of phosphorus and bioinoculants on yield, nutrient uptake and economics of long duration pigeonpea (Cajanus cajan)

A field experiment was conducted during kharif season of 2008–09 and 2009–10 to study the response of phosphorus (0, 25, 50 and 75 kg P₂O₅/ha) and bioinoculants (control, PSB, PGPR and PSB + PGPR) on yield and yield attributes, nutrient uptake and economics of pigeonpea (Cajanus cajan L.). Application of 75 kg P₂O₅/ha recorded the highest grain yield (2.19 t/ha) and yield attributes, nutrient uptake, gross returns (1,19,858/ha), net returns ( 90,500/ha) and B:C ratio (3.09), which was significantly superior over 25 kg P₂O₅/ha. Agronomic (AEp), recovery (REp) and physiological (PEp) efficiency was the highest with 25 kg P₂O₅/ha, followed by 50 and 75 kg P₂O₅/ha. REp was the highest with 50 kg P₂O₅/ha. Dual seed inoculation with PSB + PGPR produced the highest yield (2.24 t/ha) and yield attributes, nutrient uptake, gross returns (1,22,377/ha), net return (93,498/ha) and B: C ratio (3.23), being significantly superior over PGPR, PSB and control. AEp and REp was the highest with PSB followed by PSB + PGPR and PGPR, while PEp was the maximum with PGPR. The available phosphorus in soil after harvest of the crop was the highest (22.2 kg/ha) with application of 75 kg P₂O₅/ha.