A field experiment on diversification of rice-wheat system was carried out from 1999 to 2003 under assured irrigation to identify alternative cropping system with higher productivity and profitability. Sixteen rice based cropping sequences with four dominating varieties of rice viz. short duration (IET-1410), medium duration (PC-19), long duration (Jaya) and Basmati (Basmati-370) were tested. The study revealed that the existing rice-wheat cropping system should be diversified to short duration rice (IET-1410)-cauliflower-french bean which recorded highest rice equivalent yield (REY) of 27.20 t ha^-1 year^-1, net return of Rs. 105085 ha year^-1 and production efficiency of 74.52 kg ha^-1 day^-1. The REY of short duration rice (IET-1410)-potato-wheat, medium duration rice (PC-19)-potato-rajmash and basmati rice (Basmati-370)-potato-okra were next in order. Short duration rice (IET-1410)-toria-wheat had lowest system equivalent yield (11.87 t ha^-1 year^-1). Maximum energy of 77.70 x 106 K calories ha^-1 year^-1 was produced in medium duration rice (PC-19)-pea-maize (cob’s), followed by short duration rice (IET-1410)-potato-wheat and medium duration rice (PC-19)-potato-rajmash. Land utilization efficiency was maximum with rice (Basmati-370)-potato-okra (95%). After five years study, available N and soil organic carbon were found to decline in rice wheat as well as rice-toria wheat cropping sequence, while inclusion of green manuring/legumes/pulses in the system, particularly in summer season markedly improved organic carbon, bulk density as well as available N, P and K content in soil.