Irrigation is an important tool in optimizing production and improving the quality of agricultural products. However, it is necessary criteria in the use of water resources and energy expenditure in the process. This work proposes the development of a digital tensiometer for use in an automatic irrigation management system. For this, the analog gauge of a tensiometer will be replaced by a pressure sensor. The electric circuit of this sensor was designed and the tests showed that it is capable of detecting pressure variations.