Nitrogen and phosphorus nutrition of pearlmillet (Pennisetum glaucum) grown in sole and intercropping systems under rainfed conditions

A field experiment was carried out during the rainy seasons of 1997 and 1998 to assess the production potential and economics of intercropping of pearlmillet [Pennisetum glaucum (L) R. Br. emend. Stuntz] with pigeonpea [Cajanus cajan (L.) Millsp.] and castor (Ricinus communis L.) under varying fertility levels. The experiment was conducted in split-plot design with 3 cropping systems (pearlmillet sole, pearlmillet + pigeonpea and pearlmillet + castor) in main plots and 4 sets of fertility levels (control, 40 kg N/ha, 40 kg N + 30 kg P₂O₅/ha, 80 kg N + 60 kg P₂O₅/ha) in sub-plots, replicated 4 times. Intercropping had no effect on yield attributes of pearlmillet. Sole pearlmillet gave significantly higher grain yield than pearlmillet intercropped with pigeonpea or castor. Sole pearlmillet recorded higher N and P uptake than intercropped pearlmillet. The maximum pearlmillet-grain equivalent, net returns and benefit: cost ratio were obtained with pearmillet + pigeonpea followed by pearlmillet + castor. Sole pearlmillet recorded the lowest pearlmillet-grain equivalent net returns and benefit: cost ratio. The yield and yield attributes of pearlmillet pearlmillet-grain equivalent, N and P uptake and net returns were higher with higher dose, i.e. 80 kg N + 60 kg P₂O_s/ha. However, the maximum benefit: cost ratio was obtained with 40 kg N + 30 kg P₂O₅/ha and 80 kg N + 60 kg P₂O₅/ha (3.5).