It is important to understand how your sensor works, and what the readings mean, in order to get the most out of your Verdmo. 


The V.004S and V.004T measure soil moisture in the same way, but the V.004T also provides you with soil temperature and soil EC readings. Below we will go through each reading, what they mean, and how different things can affect them.


Soil Temperature (V.004T ONLY)


Let's start with the easiest one. Soil temperature is just like it sounds, the temperature of your soil at the point of the sensor. What you will notice is that the soil temperature is not the same as the air temperature. Depending on the depth of your sensor you will see a delay in your soil warming up and cooling down. 


For example, in more northern climates, in the spring your soil will show much lower temperatures even during warm days as it takes time for the soil to heat up. The same thing will happen in the fall, as the air temperature drops your soil will take time to reach the same levels. 


The deeper your sensor is placed the longer it will take your soil to heat and cool. Keep in mind that your soil will likely never reach the temperature of the air unless you are measuring right at ground level.


Soil temperature DOES affect your soil moisture and EC levels to a small degree. As the temperature increases both moisture and EC levels will rise slightly. This is completely normal, but something to keep in mind. 


Soil Moisture


All V.004 sensors measure moisture, so no matter what you ordered you will get this reading. Verdmo uses a FDR (frequency domain reflectometry) which measures capacitance of the soil. This method eliminates the concern of corrosion of the sensor probes, and Verdmo uses stainless steel to further reduce long term issues.


Your sensor will report back a reading of between 0% and 100%. We call this RWC or Relative Water Content. The reason we do this is provide you a clear way of understanding the amount of moisture in your soil, or substrate. Coming soon we will be adding a VWC or Volumetric Water Content option that will be based on the Topp equation which is a widely used calculation for mineral soils (sand, clay, loam, etc). This will provide an even better understanding of your moisture content in lawns and gardens. On top of this we will continue to add more refined options for specific soils (and soilless) in the near future.


A few things to keep in mind when looking at your soil moisture readings:


  • Temperature can affect the readings. When the temperature increases your moisture level will increase. We will be adding a "Temperature Offset" option shortly.
  • Different soil types will have different requirements to maintain a proper moisture level. For example, sandy soils will drain quickly, but also provide a high level of available water to the roots, where as clay will retain a much higher level of moisture, but the water is not as available. More information on this is coming soon.
  • The area of influence for your sensor is only a few cm's (around 1 inch) around the sensor. This means the readings will only indicate the situation directly around the sensor.
  • The connection to your substrate/soil is very important. If there are air gapes, rocks, organic material, etc it will affect the accuracy of your readings. Making sure your sensor is properly installed is extremely important.


Soil moisture can be complicated as there are many different variables that can affect the readings, but with Verdmo we are providing you with an easy to platform to build an understand of what is happening in your soil.


Soil EC


Soil EC, or salinity, is an important reading to take in your soil because it gives you an indication of how many nutrients your soil has. The higher the number the more you have, the lower the less you have. Simple, right? 


The reading you see is an indication of the overall level of "salts" in your soil, this is heavily affected by fertilizers that you add to your soil, along with other natural ingredients. While your Verdmo isn't able to tell you exactly what you need to add to your soil, it will give you an overall level that you can use to decide your next step.


Just like your moisture reading, the EC reading is affected by other things. The most important item is moisture. The higher the water content the higher the EC reading. Temperature also has some affect on the reading as well. So keep this in mind when evaluating your readings.


We will be adding some further options and metrics to the EC reading in order to give you options, and get the results you are looking for.


We are continuing to add to, and improve, our documentation all the time. Shortly we will be adding basic reading levels for different soils, lawn and plant types. If you have any questions please reach out to us at anytime.