Field experiments were conducted during the wet seasons of 1995 and 1996 at the Central Rice Research Institute, Cuttack, Orissa, India using two rice cultivars, Matangini (improved) and Champaisali (local) to study the advantages of organic manuring in conjunction with inorganic fertilizer with the objective of enhancing rice productivity under semi-deep (0–65 cm) lowland conditions. In 1995, application of 10 t FYM/ha increased grain yield compared with no FYM. The yield produced with FYM alone was similar to the yield following the application of N fertilizer at 20 and 40 kg/ha. There was no significant difference in grain yield due to the application of 20 and 40 kg N/ha in plots treated with FYM. Nitrogen fertilization was effective only when FYM was not applied. In 1996, FYM application alone or in combination with N fertilizer had a beneficial effect on crop growth and grain yield. This was contrary to the results obtained in 1995 when N fertilization at 20–40 kg/ha did not prove beneficial in plots where FYM was applied. The yield due to application of FYM alone was similar to that from the application of 40 kg N/ha as urea. However, the maximum yield was produced when FYM application was supplemented with 40 kg N/ha. There was a significant interaction between N application rate and cultivar. Cultivar Matangini outyielded Champaisali in both years.