Comparative evaluation of karanjin and extracts of karanja (Pongamia glabra Vent.) and neem (Azadirachta indica L.) seeds for retardation of nitrification of urea in soil uri icon


  • The effect of alcohol extracts of karanja (Pongomia glabra) and neem (Azadirachta indica) seeds in retarding the nitrification of urea was compared to that of karanjin in an incubation experiment. Application of the seed extracts at a rate corresponding to 30 percent of the N rate was comparable to karanjin applied at 5 and 10 per cent concentration. The extracts were effective for a period of up to 45 days, while karanjin was effective for up to 60 days. The different patterns of nitrification inhibition observed with karanja and neem seed extracts suggested an advantage in using a mixture of the two

publication date

  • 1982