The rise of the Internet of Things (IoTInternet of Things (IoT)) in agriculture has transformed traditional farming into a smarter, data-driven practice, enabling precise control over irrigation, crop healthCrop health, and resource use. Yet this increased reliance on connected sensorsSensors and cloud platforms introduces significant cybersecurityCybersecurity risks, including tampering, hacking, and destructive distributed denial-of-service (DDoS) attacks. This work offers a comprehensive review and a conceptual framework for securing IoTInternet of Things (IoT)-enabled agriculture. It examines the current landscape of smart-farming technologies, highlights vulnerabilities across system layers, and explores emerging defense strategies such as strong encryption, blockchainBlockchain, edge computingEdge computing, and machine learning-based intrusion detection. The proposed multi-layered security modelModels protects the accuracy, confidentiality, and availability of agricultural data while remaining affordable for rural deployments. By integrating authentication, secure communication protocols, and intelligent anomaly detection, it strengthens defenses against cyber threats. This study also outlines future directions for building resilient, privacy-preserving, and energy-efficient smart-farming systems capable of supporting sustainable, high-quality food production in the digital era.