Soil moisture monitoring technologies in smart agriculture: A comprehensive review

Soil moisture monitoring is a critical component of modern agriculture, directly impacting crop productivity and resource management. With increasing pressures from climate change, water scarcity, and global food demand, there is a growing need for innovative and data-driven approaches to optimise agricultural practices. This systematic and conceptual review explores the role of advanced technologies in transforming soil moisture monitoring and smart agriculture. It aims to address major global challenges, including food security, water scarcity, and climate variability. By synthesising advancements in Internet of Things (IoT), machine learning (ML), remote sensing, and related technologies, this review aims to elucidate their contributions to precision farming, resource optimisation, and sustainable agricultural practices. The review provides a comprehensive analysis of current trends, methodologies, and technological integrations, identifying key innovations that enhance crop productivity and environmental resilience. It seeks to guide researchers, policymakers, and agritech stakeholders toward scalable, inclusive solutions by highlighting research gaps and proposing future directions for equitable and sustainable agricultural transformation. ✓ HOSNA achieves 94% accuracy and 24% energy savings over traditional WSNs in field trials. ✓ LSTM, RF, and CNN models are benchmarked for soil moisture prediction accuracy and robustness. ✓ TinyML on UAVs, blockchain security, edge computing enable scalable, secure, low-latency smart agriculture. ✓ Addresses sensor calibration, rural connectivity, and cost barriers for smallholder adoption in diverse regions.