Low-cost soil moisture sensor calibration

Abstract

Brazil has been experiencing several instabilities regarding the climate. There is a great climatological variation in the cultures that have been suffering drastically from this stress, mainly water. Therefore, it is necessary to quickly and efficiently check the soil moisture rate, before any operation in the field, avoiding production losses and unnecessary extra expenses for the producer. Methods for measuring soil moisture are extremely important for carrying out adequate irrigation, thus optimizing water resources and saving water. Humidity directly affects seed quality, germination rate and crop yield, other unit operations. In this study the low-cost WeMos sensor was evaluated regarding its efficiency and possible calibration in comparison to high-cost equipment with an average of US$: 405,75 dollars. The gravimetric method was used to calibrate the sensor, which consists of sample preparation, drying, determination of its mass and evaluation calculation. The gravimetric method was used to calibrate the sensor, which consists of sample preparation, drying, determination of its mass and evaluation calculation. From the data obtained, the equation was used, which was first inserted into the programming carried out in the Arduino system transmitted to the WeMos sensor. The results obtained by the WeMos sensor were consistent with the gravimetric humidity results obtained. It is concluded that the WeMos Arduino sensor presents reliability in sampled data and that it is an economically viable option for rural producers who need to obtain an answer regarding the humidity of the planting soil.