Power tiller-driven plow tillage and crop residue exclusionary Traditional Agriculture practices are expensive, labor-demanding, soil damage, and eco-unfriendly. Over the last several years, pursuits of crop production through sustaining the productive capacity of soils, and environmental quality, have raised concern to adopt Conservation Agriculture worldwide. Single tillage combined with herbicides and crop residue retention principles of Conservation Agriculture is being developed. Between 2016–2017 and 2017–2018, a two-year on-farm experiment was done in Bangladesh. We practiced two crop establishment methods; Traditional Agriculture: Plow tillage followed by three manual weeding without residue preservation of previous crop and Conservation Agriculture: Pre-plant herbicide + single tillage + pre-emergence herbicide + post-emergence herbicide; under rice–wheat and rice–wheat–mungbean systems. Data reveal that Conservation Agriculture was a more cost-effective crop establishment technique than Traditional Agriculture in rice, wheat, and mungbean by increasing the ratio of benefit to costs by 24.3%, 35.7% and 48.8%, respectively, with savings in tillage operations (66.3%, 58.1%, and 57.6%, respectively), weeding expenditures (59.2%, 24.5%, and 42.2%, respectively), and manpower requirements (25.1%, 27.2%, and 31.3%, respectively). This has resulted in an increase of 32% productivity of rice–wheat–mungbean systems with the yield advantage of 16%, 31% and 37% in rice, wheat and mungbean, respectively. When mungbean was added, the rice–wheat system’s productivity rose by 43%. The rice–wheat–mungbean system under Traditional Agriculture had the highest land utilization efficiency (99.45%), followed by Conservation Agriculture (92.05%), which expanded the scope to include additional crops in the rice–wheat–mungbean system. Moreover, Conservation Agriculture had a 59.7% greater production efficiency than Traditional Agriculture, where the rice–wheat–mungbean system having the highest production efficiency (53.00 kg–1 ha–1 day–1), followed by the rice–wheat system (45.57 kg–1 ha–1 day–1).