The effect of green manure and nitrogen fertilizer applications on rice performance and post-harvest nutrient status of the soil was studied at the Regional Wheat Research Station of Bangladesh Agricultural Research Institute (BARI), Shyampur, Rajshahi, Bangladesh. The experiment comprised two sets of treatments: (i) green manure application (Crotalaria jusncea, Sesbania aculeata, Sesbania rostrata,Vigna radiata, and Phaseolus mungo) and (ii) application of different nitrogen levels (0, 40, 80, and 120 kg ha −1 ). Both treatments had a significant effect on the growth and yield of transplanted aman (T. aman) rice. We show that soil fertility can be maintained and rice yield can be improved through incorporation of green manuring and nitrogen fertilizer management. Green manure and nitrogen management generated positive responses in important morpho-physiological traits such as leaf area index (LAI), specific leaf area (SLA), crop growth rate (CGR), leaf relative growth rate (LRGR), leaf weight ratio (LWR), and net assimilation rate (NAR), which may result in a greater contribution of yielddetermining traits and eventually higher grain yield. The results indicate that all green manures in combination with higher N levels accelerate SLA, LWR, LAI and CGR. Better performance of potential yield-contributing characters and relatively higher nitrogen uptake and higher N and protein content in grain and straw were found in combination with all green manure and higher N level treatments. An increasing level of post-harvest soil nitrogen content was observed with the application of higher levels of nitrogen in combination with green manures. Therefore, green manuring in combination with judicial nitrogen fertilizer management is deemed necessary for sustainable T. aman rice cultivation.

The treatments were T0(control), T1(N100P15K45S20 (Recommended dose), T2 (50% NPKS+5 t ha -1 CD), T3 (70% NPKS+3 t ha -1 CD), T4(50% NPKS+4t ha -1 PM ), T5 (70% NPKS+2.4 t ha -1 PM ), T6 (50% NPKS+10 t ha -1 DH) and T7 (70% NPKS+6 t ha -1 DH). The result demonstrated that the grain and straw yields were significantly influenced by the added fertilizers and manure. Application of 50% of NPKS fertilizers plus 10 t ha -1 dhaincha produced maximum grain yield (5085 kg ha -1 ) which was identical to that obtained with 70% of NPKS with 6 t ha -1 dhaincha. In case of straw yield, the treatment T7 (70% NPKS+6 t ha -1 DH) produced the highest yield (5470 kg ha 1 ) and then (5250 kg ha -1 ) yield obtained from T6 (50% NPKS+10 t ha -1 DH) treatment. The grain yield increases over control ranges between 115 to 176%. Grain yield of T. Aman rice was positively correlated with plant height, number of effective tiller, panicle length, filled grains panicle -1 and straw yield. The overall findings of this study indicate that the integrated use of fertilizer and manure should be encouraged to address the deteriorating soil fertility and increased crop yield of T. Aman rice.