Md. Abul Kalam Azad

One simple way to measure soil temperature is by using an ordinary thermometer (or any cheap soil thermometer from stores selling garden supplies). First, dig a small hole using a wooden stick down to the rooting depth, then insert the thermometer and after 3-5 minutes get the reading. It would be important to get several readings from different parts of the field to get a good average value.

You can use ordinary thermometer. Based on your purpose, you can choose different soil depth to take temperature.

I do agree with Victor B. Asio . It can easily be used