The VIA has three systems that can be used independently or in combination
The Chameleon Card is our most simple system to use.
The Chameleon Card System consists of three or six Chameleon sensors together with a credit card sized reader. The sensors are permanently buried, with the wires attached to a stake in the ground. To measure the soil water status, the wires are placed into the slots in the card reader. The LED on the card will turn blue (wet), green (moist) or red (dry) to show the soil water status at each location.
Sensors can be placed to measure at one depth in different locations or at several depths in one location.
The reader does not store data or have any wireless communications.
The Chameleon Wi-Fi System reads, stores and sends data to the VIA website platform. It is connected to a Chameleon sensor array. The sensor array consists of three soil water sensors placed in the top, middle and bottom of the rootzone plus a temperature sensor, which gives the array a unique digital identifier. The Reader has three LEDs, one for each Chameleon sensor.
The Chameleon Wi-Fi Reader can be permanently connected to a sensor array. In this case, it will log a reading every two hours. The Wi-Fi Reader can be paired to a Wi-Fi access point for continuous data delivery, or to a mobile phone for upload when visiting the crop.
A Wi-Fi Reader can also be used to manually take and store data from many sensor arrays. This is an economical option for when data is required less frequently (daily or weekly) from many different locations.
The Wetting Front Detector (WFD) records the depth of infiltration of irrigation water. The WFD is buried in the root zone. When the infiltrating water goes past the WFD, it captures a water sample and pops up a magnetically latched indicator.
The WFD stores this soil water sample for later analysis. The water sample is removed using a syringe. All dissolved salts are measured using a VIA Electrical Conductivity (EC) meter. Nitrate, which is the most difficult nutrient to manage in irrigation, is measured with colour strips.
WFDs are used as irrigation management tools, particularly to identify over-irrigation and water logging. However, their main use is for solute monitoring in conjunction with the VIA EC meter and nitrate test strips.
The Chameleon soil water sensor is at the heart of the VIA. The sensor is comprised of an inner core of highly absorbent sensing material encased in a gypsum buffer. The sensing material absorbs water when the soil gets wet and releases water as the soil dries. When the sensor is connected to a Chameleon Card or WiFi Reader, the water status will be displayed as a blue (wet), green (moist) or red (dry) light.
Most soil water sensors provide a number telling you how much water is in the soil. This number must be interpreted for each soil type. For example, a sand holds less water than a clay soil. The Chameleon sensors tells you how hard the plant must suck to extract water from the soil. Blue means wet soil, both in a sand and in a clay soil.
No, the sensor is not a gypsum block.
For those familiar with soil water measuring, the Chameleon soil water sensor has similarities to the "gypsum block" and tensiometer. The mode of operation is as simple as the gypsum block, however it is the unique sensing material inside the Chameleon sensor that makes it stand out. The sensor provides a high resolution in the part of the soil moisture range most critical for irrigators. The Chameleon sensor covers the same soil water range as the tensiometer but is cheaper and simpler to use.
Yes, remarkably accurate for an inexpensive sensor.
It took us three years to develop the Chameleon sensor. It took another three years to be able to make thousands all with the same accuracy. See other FAQs for the suction at which the colours change, sensor longevity in the ground and the effect of salt.
The sensor gives a measurement resistance, which is laboratory calibrated to soil suction. Each soil type has a unique relationship between the soil water content (the amount of water in the soil) and the soil water suction (the stress experienced by the plant). If you measure soil water content, there is a different 'number' for which you must irrigate each soil. If you measure soil water suction with a Chameleon sensor, the blue, green and red colours mean the same from the perspective of plant stress, regardless of soil type.
There are huge benefits in measuring water and solutes together. The Chameleon Card coupled with a WFD, EC meter and nitrate test strips provides a simple way to visualise water entering the rootzone, extraction of water by the crop and the accumulation and flushing of nitrate and salt.
When using the Chameleon Wi-Fi System in conjunction with the WFD, the change in solutes can be visualised together with the water pattern on the VIA data platform.