Systems, methods and apparatus are provided for monitoring soil properties including soil moisture, soil electrical conductivity and soil temperature during an agricultural input application. Embodiments include a soil reflectivity sensor and/or a soil temperature sensor mounted to a seed firmer for measuring moisture and temperature in a planting trench. A thermopile for measuring temperature via infrared radiation is described herein. In one example, the thermopile is disposed in a body and senses infrared radiation through an infrared transparent window. Aspects of any of the disclosed embodiments may be implemented in or communicate with an agricultural intelligence computer system as described herein.