The NPK Sensor is used to measure the nutrient levels of Nitrogen (N), Phosphorus (P), and Potassium (K) in soil, which are essential for plant growth and health. These three macronutrients play a crucial role in plant development, influencing factors such as root growth, flowering, and fruiting. The NPK sensor provides real-time data, allowing farmers and gardeners to monitor soil nutrient content and adjust fertilization accordingly. It is commonly used in precision agriculture, hydroponics, and smart gardening systems, typically integrated with microcontrollers like Arduino or Raspberry Pi for automated monitoring and data logging. By ensuring the proper balance of NPK nutrients, this sensor helps optimize plant yield and health.