Smart farming has become a central direction in digital agricultural transformation, yet adoption among small and medium-sized farms remains uneven because readiness depends on more than technology availability. This article develops a conceptual digital readiness maturity model for smart farming adoption among small and medium-sized farms. The model is literature-grounded and designed to classify farms across progressive readiness stages rather than treating adoption as a binary decision. It integrates core readiness dimensions, including digital infrastructure, connectivity, device and machinery access, data availability and quality, data literacy, digital skills, affordability, perceived usefulness, trust, data privacy and ownership, farm-management routines, advisory support, cooperative networks, institutional support, interoperability, sustainability orientation, and farmer-centered usability. The proposed maturity logic distinguishes five levels: non-digital or initial readiness, basic digital access, connected and data-aware farming, integrated smart farming use, and adaptive learning-oriented smart farming. The article contributes to smart farming adoption research by positioning maturity as a staged, context-sensitive capability-building process. For small and medium-sized farms, the model provides a practical conceptual tool for identifying readiness gaps, prioritizing support interventions, and aligning digital transformation with farm goals, advisory capacity, institutional conditions, and farmer decision contexts.