Smart irrigation is a cornerstone of Agriculture 5.0, integrating IoT, artificial intelligence (AI), and big data analytics to optimize water use and improve crop yields. Despite proven efficiency gains, adoption in India remains critically low due to high capital costs, technical complexity, limited awareness, and infrastructural deficits. AI-driven digital marketing presents a novel avenue for bridging these gaps, yet its adoption pathways and sustainability impacts are not well documented. This study aims to examine how algorithm-enhanced digital marketing strategies influence farmer decision-making and adoption of smart irrigation technologies in India. Specifically, it seeks to identify behavioural drivers, quantify sustainability outcomes, and establish an integrated framework—termed “Drip by Click”—for scaling irrigation innovation. A hybrid qualitative–diagnostic methodology was employed. First, a PRISMA-guided systematic literature review synthesized 78 peer-reviewed studies on smart irrigation and digital agriculture. Second, embedded case analyses were conducted across four agro-climatic zones (Punjab, Telangana, Maharashtra, and Kerala), representing diverse water stress levels and digital infrastructure. Thematic synthesis examined adoption pathways, barrier mitigation strategies, and sustainability outcomes, triangulating literature evidence with field cases. AI-personalized advisories increased adoption intent by 3.2 times, while loss-aversion framing reduced decision latency by 40%. Augmented reality tutorials lowered installation errors by 81%, and integrated digital channel stacks (e.g., IVR combined with community radio) improved engagement by 74–89% in low-connectivity regions. Digitally guided adopters demonstrated 78% higher water efficiency (5.7 vs. 3.2 megaliters per season), 41% less fertilizer leaching, and an 80% reduction in carbon footprint. Economic resilience improved through a 13% reduction in input costs, 22% yield gains, and a 25% higher drought survival rate.