Efficient nutrient management is a key determinant of plant health, crop productivity, and sustainable agricultural practices. Conventional nutrient management methods rely on periodic soil and plant analysis, which are often time-consuming and incapable of providing real-time information on nutrient dynamics. These limitations result in inefficient fertilizer use and nutrient imbalance. To address these challenges, this paper presents the design and development of a sensor-based nutrient management system integrated with the Internet of Things (IoT) for real-time monitoring of plant health in crop science. The proposed system focuses on the development of intelligent nutrient sensors capable of measuring critical soil parameters such as nitrogen, phosphorus, potassium, soil moisture, pH, and electrical conductivity. Sensor data are processed through a microcontroller and transmitted to cloud platforms through IoT communication technologies. The system enables real-time monitoring, analysis, and decision support for optimized fertilizer application. The integration of IoT facilitates remote monitoring and automation, supporting precision agriculture applications. The proposed approach enhances nutrient use efficiency, reduces excessive fertilizer application, and improves plant health throughout the crop growth cycle.