Global food security faces unprecedented challenges as the population nears 9.7 billion by 2050, demanding 70% increased food production. Conventional farming methods suffer from inefficiencies including 30% water waste and delayed crop stress responses. While IoT-enabled precision agriculture offers 30% water savings and 20% yield improvements, current solutions are fragmented, expensive, and inaccessible to smallholder farmers producing most agricultural output. However, existing systems lack integration and affordability for widespread adoption. This study addresses these limitations by developing EcoFarm 360, an integrated low-cost smart farm system combining wireless sensor networks and renewable energy infrastructure for comprehensive farm management. The research was a rigorous six-step process of system design, prototyping, integration, and prolonged field trials on diversified large-scale agricultural operations of different sizes. Empirical verification shows considerable performance gains: 34% water efficiency improvement, 18.5% yield, and quick return on investment within 14–18 months, with yearly savings of 12,400 BDT per farm. The intuitive dashboard interface of the system attained 94% user satisfaction levels, confirming real-world usability for farmers with different technical skills. These findings place EcoFarm 360 as a viable and scalable solution to addressing contemporary farming issues and promoting resource efficiency and economic viability in diverse farming environments.