The present investigation was carried out in a holistic mode to study the interactions among the integrated farming system (IFS) components and to develop and design a sustainable IFS model which is technologically sound, economically viable, environmentally benign, and socially acceptable for the middle Indo-Gangetic Plains. For efficient utilization of farm resources and to enhance the income per unit area of land, 10 IFS models have been developed at the farmers’ fields of Patna, Nalanda, and Vaishali districts of Bihar, India, during 2016–2021, involving components like crops, poultry, cattle, goat, mushroom farming, fishery, and duckery in different combinations. Out of 10 different integrations, three primary cropping systems prevailing in the state were undertaken and seven other components were integrated in a synergistic mode. Each system was allocated an area of 0.8 ha (2,000 m²), viz., (i) rice–wheat, (ii) rice–maize, (iii) rice–maize–moong (crop), (iv) crop + vegetable + goat, (v) crop + fish + goat, (vi) crop + fish + cattle, (vii) crop + fish + duck + goat, (viii) crop + fish + duck, (ix) crop + fish + mushroom, and (x) crop + fish + poultry. To sustain the productivity of soil health, inorganic fertilizers combined with organic wastes, obtained from various components of IFS, viz., recycled pond silts, poultry manure, duck manure, goat manure and cow dung as farmyard manures (FYMs), composted residues, and vermicompost were applied to crops grown under different IFS models. The nutrient content of manure increased manifolds after recycling as compost and vermicompost. Residue recycling revealed that integration of crops with fish and duck resulted in higher fish productivity and higher net returns (increased by USD13) in comparison to poultry dropping fed fishes. Due to the recycling of droppings, viz., poultry, duck, goat, cattle, and plant wastes, an additional quantity of 56.5 kg N, 39.6 kg P2O5, and 42.7 kg K2O was added to the soil during the study. Crop integrated with fish + duck + goat had the maximum rice grain equivalent yield (RGEY), net returns, and employment opportunity (467 man-days/year) from 0.8 ha of land, followed by crop + fish + poultry integration. The sustainability index (0.77) and net energy gain (95,770 MJ) were also found highest with crop + fish + duck+ goat integration indicating the optimum efficiency of all the farming system integrations for the region.