The water particles held in the gaps between the soil molecules are called soil moisture, as per soil science terminology. Measuring this moisture is important, because it helps in irrigation scheduling, estimating crop yields, and reservoir management.
Soil moisture measurement gives us an idea about soil erosion, slope failure, and the quality of the water. It also gives early warning of droughts and floods. It helps to control water evaporation and heat energy released through plant transpiration between the soil surface and the atmosphere.
It is a potent variable in the downfall of water and the development of weather patterns. Agencies and companies, that are concerned with water and weather, use soil moisture equipment for measuring and monitoring.
Process to Measure Soil Moisture
There are various types of soils and each of them has a different capacity to hold water. This capacity depends upon the parameters, such as structure and texture of the soil, vegetation in the area, etc.
Soil moisture level can be estimated by the feel and appearance of the soil, but using the right equipment gives accurate results. Nowadays, various measuring and monitoring methods and equipment are widely used for this purpose.
Soil Moisture Meters
Various soil moisture meters, such as tensiometers, equitensiometers, and moisture meters are available in the market. They are simple to use and give accurate results.
- The tensiometer is used for the estimation of soil water suction.
- It is a sealed tube, which is filled with water.
- It has a special ceramic, porous tip and vacuum gauge on the upper end.
- Its length ranges from 6 inches to 72 inches.
- It is used to determine the irrigation needs, when the soil moisture is above 50% of the field capacity.
Neutron Moisture Meter
- In a neutron moisture meter, state-of-the-art electronics and radioactive sources are used.
- As the radioactive source can be harmful for health, using the neutron moisture meter requires a license.
- It gives accurate results, but it is an expensive equipment.
Soil Moisture Sensors
- Sensors are usually buried in the soil.
- They are either hard-wired to a fixed meter or they may have long attached electrodes, which are placed on the soil surface and hooked to a portable meter.
- Recording readings and plotting charts increases the precision of these sensors.
- For soil moisture sensing, electrical resistance blocks are most commonly used.
- Soil moisture monitoring techniques are easy to learn and also cost-efficient.
- These methods help to optimize crop yields, conserve water and energy, and prevent soil erosion and water pollution.
- Soil moisture control, monitoring, prediction, and irrigation scheduling are extremely important. Various probes and loggers are used for soil moisture monitoring.
Soil Moisture Probes
- Probes are automatic, electronically-operated soil monitoring devices.
- They are very useful in environmental monitoring, irrigation, rain monitoring, sprinkler systems, weather monitoring, moisture monitoring of bulk foods, water conservation applications, and fluid level measurements.
These soil moisture equipment are very helpful in biofuel studies, archeology, erosion studies, drought and flood forecasting models, and landslide studies.
They are also used in phyto-remediation, which is a process, in which soil or water is decontaminated by using plants and trees to, either absorb or break down pollutants. Thus, soil moisture levels help in ascertaining various geological, biological, and hydrological studies.