Soil conductivity sensor,also known as EC sensor, is widely used to measure soil conductivity in agricultural production. However, there is still confusion about what these readings mean and how they can be used for precision farming.
To what extent can Soil conductivity sensor be used for “precision fertilizer management”? In fact, “soil conductivity ” may refer to different types or methods of EC readings, each with its own meaning. We will explore the significance of different EC measurements and assess their applicability in precision agriculture.
The electrical conductivity is the ability of a material to transmit electrical current. The question is, therefore, which medium is being measured and how can the reading be interpreted and used?
The most commonly used EC measurement in IOT agriculture is the soil bulk EC, or soil apparent EC (ECa). This soil EC correlates with various soil properties, such as soil texture and water holding capacity. Sandy soils will have a lower EC reading than clay soils.
Other methods to evaluate electrical conductivity of soil focus on measuring the EC of the soil-solution, hence its salinity. The difference between these methods is mainly the moisture state of the soil. The electrical conductivity of the soil-solution changes continuously, depending on the moisture content of the soil. Therefore, for standardization, all EC measurements must be taken at the same moisture content.
The most acceptable moisture content is the moisture of ‘saturated paste’, also referred to as ‘EC of the saturated paste extract’. EC gives an indication of the soil salt content. It can be used to estimate whether there is excess of salts in the soil. However, it does not imply exactly which salts and nutrients are present.
Soil conductivity sensor in IOT agriculture are a valuable tool for better understanding variability and trends in the soil. This is especially true for soil EC mapping and to a much lesser extent to stationary single soil sensors. However, precise fertilization management is a complex process, that takes into consideration multiple variables and parameters, well beyong beyond EC alone.