An experiment was carried out at the research field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh with the objective of verifying the effects of different salinity levels on the germination, growth and yield of four irrigated rice (Oryza sativa L.) cultivars. The experiment was performed with 6 NaCl concentrations viz. 0, 30, 60, 90, 120 and 150 mM. It was observed that seed germination, plant height, tiller number and leaf area index are negatively influenced by different salinity levels in all the rice varieties. All the yield components that is number of panicles, panicle length, spikelets per panicle, filled grain and grain weight also significantly decrease with the increased salinity stress. An increase of NaCl concentration up to 150 mM decreased 36-50% of the grain yield of all the four rice varieties. Among the varieties BRRI dhan41 showed better performance at salinity stress up to a certain level.

The experiment was conducted at the Agronomy field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh (90033´ E longitude and 23077´ N latitude) during June to November, 2008 with a view to observe the comparative performance of different organic manures and inorganic fertilizers on the growth and productivity of transplanted rice. The experiment comprises of 10 treatments viz. T1 (Control), T2 (Green manure @ 15 t ha-1), T3 (Green manure @ 15 t ha-1 + N40P6K36S10 i.e.50% NPK), T4 (Poultry manure @ 4 t ha-1), T5 (Poultry manure @ 4 t ha-1 + N40P6K36S10 i.e. 50% NPK), T6 (Cowdung @ 12 t ha-1), T7 (Cowdung @ 12 t ha-1 + N40P6K36S10 i.e. 50% NPK), T8 (Vermicompost @ 8 t ha-1), T9 (Vermiconpost @ 8 t ha-1 + N40P6K36S10 i.e. 50% NPK) and T10 (N80P12K72S10 i.e.100% NPK). Plant characters, yield attributes and yield was significantly influenced by different treatments. Except plant height, total tiller per hills and biological yield all the parameters were found to be highest with the treatment T5 (Poultry manure @ 4 t ha-1 + N40P6K36S10 i.e. 50% NPK). From our study we observed that among the treatments T5 (Poultry manure @ 4 t ha-1 + 50% of recommended NPK) produced the highest grain yield (4.79 t ha-1) of rice which was statistically identical to T10 (100% of recommended NPK) and T9 (Vermicompost @ 8 t ha-1 + N40P6K36S10) which resulted grain yield of 4.57 t ha-1 and 4.51 t ha-1, respectively. Vermicompost was found as the best manures when it was applied alone. The economic analysis also showed that the application of T5 maximized the profit and benefit-cost ratio (BCR) was the height (1.75) in the treatment which was almost similar to T10. The lowest BCR (1.07) was obtained from control treatment (T1).