Balh Valley in the northwestern Himalayas in India is well known for cultivation of high-value cash crops and vegetables. The Indo-German Agricultural Project executed four decades ago in the valley has been the driving force for agrarian development in the valley, but crops are still grown under nutrient-starved conditions, giving low productivity compared to national averages. To demonstrate and disseminate the integrated nutrient management (INM) technology in the irrigated ecosystem of Balh Valley, efforts were funded by the Indian Farmers' Fertilizers Cooperative Limited (IFFCO) to develop sustainable crop production systems under cash crops and vegetables following an appropriate technology transfer model by Krishi Vigyan Kendra (KVK), Sundernagar, India. For effective technology transfer, field demonstrations, method demonstrations, farmers' training camps, field days, and numerous field conventions were organized in addition to extending soil testing, literature supply, promotional seed and fertilizer input supply, and training of agro-cooperative society personnel who deal with seed and fertilizer input supply in the region. The greater extension gaps in tomato–blackgram and potato–Kharif onion crop sequences indicated need for effective technology transfer tools for high adoption of technology in these production systems in the valley. Potato–Kharif onion cropping system using INM technology resulted in greater system productivity in terms of blackgram equivalent yield (76.7q ha−1) and gross (3,06,920 ha−1) and net returns (2,22,295 ha−1), followed by tomato–blackgram and green pea–okra production systems, respectively, using an appropriate technology transfer model. The study also revealed improvement in available nitrogen (N)–phosphorus (P)–potassium (K) and organic carbon (C) pool of the soils besides crop productivity and profitability in field trials under INM practices over farmers' practiced plots. Knowledge before the study about soil testing, dose and time of application of organics, chemical fertilizers, and their integrated use ranged from 9 to 41%, whereas knowledge increases after the study ranged between 55 to 88%. The INM technology adoption rate after 1 year of project completion ranged between 66 to 70%, whereas soil testing was done by only 35% of farmers. Thus, INM technology adoption rate was greater following the appropriate technology transfer model based on critical analyses of fertilizer use, existing production systems, and appropriate interventions for technology transfer. This comprehensive study under the IFFCO-KVK Collaborative Project attempts to highlight that an effective technology transfer model can play a key role in adoption of INM technology for sustainable production systems in the developing world, especially for resource- and knowledge-poor farmers of collateral socioagroeconomic environments of developing nations.