A soil moisture sensor is a device used to measure the amount of water present in the soil. It helps determine when plants need watering, ensuring they receive the right amount of moisture for healthy growth. These sensors can be used in agriculture, gardening, and landscaping to optimize irrigation practices. Typically, soil moisture sensors work by using electrical resistance or capacitance to gauge moisture levels. They can be connected to automated irrigation systems, allowing for efficient water usage. By monitoring soil moisture, these sensors contribute to sustainable farming and help conserve water resources.