Understanding Soil Moisture and How It’s Measured

All soil is not created equal, and the way we use soil varies from application to application. Reading soil moisture to collect data can produce quite a bit of useful data such as climatic patterns, crop growth data, carbon cycles and weather predictions. In horticulture, we use this data to maximize irrigation efficiency for our crops and cuttings. Knowing the ratio between water and soil can help determine which species of plants will prosper with more water, and which ones need very little. Additionally, measured data will determine how hard the plant must work for optimal growth in a specific location. It’s also worth noting that different soils have different densities, therefore work with different tensions even with proper volumetric measurement. Measuring soil moisture, while it seems like a daunting task, is not as hard of an activity as it seems. Phytotronics has two main tools that help with soil water tension and volumetric water measure.

Phytotronics Volumetric Water Sensor

Our soil tension water sensor enables precise low-cost monitoring of soil water content. The sensor consists of a pair of highly corrosion resistant electrodes that are embedded within a granular matrix. A current is applied to obtain a resistance value. The transmitter correlates the resistance to Centibars (kilopascals) of soil water tension. This measuring tool is meant to be a permanent solution as it’s placed in the soil that needs monitoring. The sensor can transmit within a 0-200 centibar range. Internally installed gypsum provides some buffering for the effect of salinity levels normally found in irrigated agricultural crops and landscapes. The best use of this sensor is for outside in field soils.

Phytotronics Soil Tension Water Sensor

The volumetric probe measures the dielectric constant of the soil using transmission line techniques, it is insensitive to water salinity, and will not corrode over time as does conductivity based probes. The data output is proportional to moisture level, and will provide an accurate reading every time. Readings are displayed as 0-50% water volume and are best used in pots and containers. Our sensor also can provide value for food production, as it measures moisture in consumer food products. This is especially useful for harvesting, production and transport.
Our probes are small, rugged, and low power. Our probes transmit data every 12 minutes, only requires 2 AA batteries and communicates wirelessly with our AT101 hub, and can complement other AT200 products. Probes are made to last, water resistant, and will not malfunction due to freezing temperatures and other elements.

Understanding soil moisture and how it’s measured is imperative to proper growth and sustainable crops. We can immediately determine how good our soil is, but also predict future climate changes and how it will impact our yields. These tools will become a cornerstone of your crop yield forecasting, as well as irrigation planning.



Why Phytotronics?

  • Phytotronics is the safer technology for the modern grower
  • Phytotronics products enhances your growing power and profitability
  • Solutions for a better harvest

For over 36 years Phytotronics has been an innovative manufacturer of precision equipment and supplies for the commercial greenhouse and nursery grower. Our Phytotronics line of mist controllers and related equipment, as well as the Rhizopon™ are used by professional plant propagators and growers across North America.