Integrated nutrient management in groundnut (Arachis hypogaea) in subtropical humid climate of north-east India

An experiment was carried out at the ICAR Research Complex for NEH Region, Lembucherra, Tripura during 3 consecutive kharif seasons 2008–2010 to study the effect of integrated nutrient management on groundnut (Arachis hypogaea L.). The experiment was laid out in randomized block design with 3 replications and 10 treatments, viz. T₀, control, T₁, 10 t FYM/ha;T₂, 50 kg P₂O₅/ha; T₃, 50 kg P₂O₅+ 10 t FYM/ha;T₄, 50 kg P₂O₅+ 50 kg K₂O/ha; T₅, Rhizobium; T₆, 10 t FYM/ha + Rhizobium; T₇, 50 kg P₂O₅/ha + Rhizobium; T₈, 50 kg K₂O + 10 t FYM/ha and T₉, 50 kg P₂O₅+ 50 kg K₂O/ha + Rhizobium. Application of Rhizobium culture in combination with 50 kg P₂O₅ + 50 kg K₂O/ha resulted in the highest pod and seed weight/plant. The inoculation of Rhizobium culture along with 50 kg P₂O₅ + 50 kg K₂O/ha showed 45% increment in pod yield (from 1.37 to 1.95 t/ha) over the control. The highest haulm yield (3.57 t/ha) was obtained with FYM 10 t/ha, The lowest cost of cultivation and energy input were recorded with the control. However, significantly higher total returns ( 84,020/ha), net returns ( 58,447/ha), energy output (49.8 × 10³ MJ/ha) and net energy (43.2 × 10³ MJ/ha) were recorded with inoculation of groundnut seed with Rhizobium culture along with soil application of 50 kg P₂O₅ + 50 kg K₂O/ha. The highest benefit: cost ratio (3.52) was recorded in plot, which was inoculated with Rhizobium culture. Highest energy-use efficiency (7.50), energy productivity (0.30 kg pod yield/MJ) and lowest specific energy (3.37 MJ/kg pod yield) were recorded in plot inoculated with Rhizobium culture