A device for determining soil compaction includes a control member fitted with one or more sensors that measure the response of the control member during co-action between the control member and a soil surface. In one embodiment, this response can be flexure as characterized by a measurable parameter such as strain. A measurement module in communication with the sensor or sensors determines a soil modulus for the soil based on the strain measurement from the sensor or sensors. In one arrangement, the control member includes one set of sensors that measure radial strain and another set of sensors that measures hoop strain. The device can also include a load sensor for measuring the load applied to the control member. In one embodiment the measurement module includes a processor that determines soil modulus based the strain measurements and the measured load.