The management of irrigation based on the monitoring of soil electrical parameters allows to rationalize the amount of resources used with the objective of developing a sustainable agriculture. In this sense, the present work presents a sensor of dielectric constant and conductivity of soil based on auto-balancing bridge circuit. The advances presented in this paper are related to the evaluation of the system in the field and to the development of a model for correcting the effect of ambient temperature on the measurement circuit of the sensor, through multiple linear regression. In this way, the reproducibility of the system was improved.