The effect of organic, inorganic and integrated nutrient management practices on release pattern of nitrogen fractions under five different cropping systems mainly Soybean-Wheat, Groundnut-Sorghum, Maize-Chickpea, Potato-Chickpea and Chilli+Cotton was studied by conducting field experiment during both kharif and rabi seasons of 2007-08 at UAS, Dharwad, Karnataka. The study conducted was the fourth year of long term field experiment (LTFE) of Network project on organic farming at Institute of Organic Farming, UAS, Dharwad. At the end of kharif and rabi season of fourth year 2007-08, the organic and inorganic forms of nitrogen were significantly high under organic nutrient management practices than with inorganic nutrient management practices, however was on par with integrated nutrient management practices. Among the organic N fractions, total hydrolysable N fraction accounted for a major portion of organic N followed by acid insoluble N of soil. Among the cropping systems, legume based cropping system during both kharif and rabi seasons recorded significantly higher organic and inorganic forms of nitrogen in the soil than non-legume system. At the end of kharif and rabi season of fourth year (2007-08), application of organic manures resulted in significantly higher organic carbon. Whereas integrated application of manure and fertilizers resulted in significantly higher available N, P2O5, K2O and S than chemical fertilizers alone. Significantly higher uptake of N, P and K by kharif and rabi crops was recorded in integrated practice compared to inorganic nutrient management practice. The available N, P2O5, K2O and S were significantly higher in legume based cropping systems during both the seasons of the study than non-legume system.