The rice-wheat annual double cropping system occupies an estimated 0.5 million hectares in Nepal where it provides food for about 23 million people. Current production levels of both rice and wheat are far below their reported potential with N-deficiency being the major production constraint. Pot and field experiments were conducted in the greenhouse and under field conditions at various sites in Nepal between 2001 and 2003 to assess the potential of wheat straw management, grain and green manure legumes and combinations of those on soil N dynamics, crop yields and system N balances.