Nitrogen (N) is a nutrient essential to all forms of life. N in the biosphere is highly reactive and is rapidly cycled. Although N is the most abundant element in the atmosphere, it's a precious commodity -- a limiting nutrient -- in most undisturbed natural systems. This study was carried out for a preliminary understanding of terrestrial N cycle with Indian agroecosystem in particular.The major N pools and fluxes of agroecosystem with its allied consumer sectors of human, livestock including poultry, their products and by-products were estimated for the recent period. The temporal changes to these estimated pools and fluxes resulting from various anthropogenic influences were also studied. In agroecosystem, the major inputs to N cycle include wet deposition as nitrate nitrogen through rainfall, biological nitrogen fixation by nitrogen fixing leguminous and other crops, and dry N deposition by use of inorganic nitrogenous Fertilizers.The total crop N pool, being the largest(including economic and residual)was estimated.The major estimated consumer pools and fluxes include human (& their related fluxes such as food consumption, nitrogenous wastes,livestock & poultry,its waste etc.