Published 22.10.2020 Determination of soil moisture is one of the main observations in agrometeorological monitoring.
Soil moisture is usually represented as a dimensionless ratio between two mass or volume values. On the state observation network of Kazakhstan, soil moisture is determined in millimeters of moisture per volume of soil or as a percentage of moisture by mass or volume.
For a long time, soil moisture was measured by taking soil samples manually and drying them in a drying Cabinet.humidity was calculated as the ratio of the mass of dry soil to the mass of the sample taken. This is a rather time-consuming thermostatic-weight method.
Now the observation network uses a modern electric device Delta-T, which is based on measuring the time of passage of an electric pulse through a cable, which depends on the electrical conductivity, and it in turn depends on the soil moisture.
In the spring, a hole 100 cm deep is drilled in the soil at the observation site. a special thin-walled channel tube is installed in it, which maximizes the penetration of the electromagnetic field into the surrounding soil. This tube allows you to measure soil moisture throughout the growing season.
To measure the moisture content in the soil, use the Profile Probe sensor. It is a rod with electronic sensors installed in it and allows you to measure the moisture content of the soil at different depths.
The output signal from each sensor is a simple analog DC voltage. These output signals are easily converted to soil moisture readings using the integrated General calibration system.
The equipment is very complex, but the analysis itself is very simple and can be performed in minutes. The device can hold the measurement results in memory for a long time.