The design of the Sensoterra probe is a game changer on four different features:
These unique features are essential for a device to function in the world of Internet-of-Things. Millions of data sources are combined to improve operations. Growers obtain higher yields, better product quality and more efficient use of resources like water, fertilizer, and pesticides.
Due to the unique Sensoterra features, growers can start to use many soil moisture probes. Typically, we recommend 3-6 probes per pivot or irrigation control area. Depending on the crop type, we recommend probes at different depths, emphasizing measurements at the active root zone.
Installing Sensoterra soil moisture probes is simple, quick, and easy. The probes are designed for with the farm in mind, built rugged, robust, and to last.
Best performance is obtained when the probes are pushed into the soil, without pre-digging a hole. In that case, soil contact is optimal and soil disturbance is minimal. If the soil is too hard to push the probe in by hand, there are 3 options:
Your gateway is easily installed. Once removed from the box, plug in the power cord, and attach the antennas to the correct ports. When plugged in, it becomes operational after about 10 minutes. Please make sure that the right antennas are placed for the cellular connection and for the RF/LoRa connection. Watch a gateway installation video.
Proper placement of the gateway considerably improves the communication range. Avoid obstructions like steel structures or water tanks. A gateway placed higher (between 10-30 feet, 3-10 meters) significantly improves the range. Most gateways have an SMA connector that can be fitted with an external antenna and an extension cable. Keeping a line of sight between the gateway antenna and the probes ensures connectivity.
The Sensoterra soil moisture sensors have an accuracy of 99.5% and is calibrated for all soil types. At Sensoterra, we are continuously improving our technology offering for our customers and partners.
Soil moisture is measured based on a proprietary and patent-pending algorithm that combines impedance and resistance properties of the soil.
The absolute soil moisture reading depends on the soil type. Currently, the probes are calibrated for the following soil types: sand, clay, clay-loam, saline clay, and peat, all of which have different characteristics. You can choose the right soil type in the app. If you are not sure about the soil type, we recommend you use the dominant soil composition type.
The reading of the probe will change if you change the soil type. Soil moisture ranges from 0% to 40% for sand, 53% for clay and 83% for peat. Maximum soil moisture is set by the void volume in the soil that can theoretically be occupied by water.
If the correct soil type is selected, the accuracy of the measurements is 99.5% correct. This means a deviation of maximum ±.5%. In our experience, that is more than sufficient for most applications. When using a calibration curve that is developed specifically for the soil, the accuracy is significantly higher.
Repeatability accuracy is 97%. That means, when measuring a sample of certain soil moisture, the probe comes back with the same reading, even if a different probe is used or a different sample is used (of the same soil type and soil moisture content). Therefore, soil moisture trends are highly accurate.
Sensoterra soil moisture readings are affected by salinity. An increase in salinity of more than 0.5 mS/cm will give a 20% relative error. This is only observed in more extreme conditions, like when saline water is used for irrigation. Normal fertilizing practices stay typically below 0.5 mS/cm.
The energy consumption is extremely low, allowing for years of operation. Batteries don’t need changing. The probe is watertight for rain and irrigation (IP65) but it should not be submerged in water. All Sensoterra probes have a lifetime of 3 years.
The probe measurements are sent by radio (LoRaWAN) to a gateway. In most cases, you will have to purchase and install a gateway yourself. In some cases (mostly urban), a local communication provider has installed public gateways. In that case, you don’t need to install a private gateway yourself. We expect that going forward, more and more area will be covered by the providers, reducing the need for customers to install gateways.
Data is sent by LoRaWAN from the probe to the gateway. With the 2G/3G/4G cellular connectivity, the data is sent from the gateway to a server owned by the provider, and through the cloud to the Sensoterra server. Sensoterra has covered the cost for the provider gateway for a period of 3 years. After that, you will have to decide whether to continue the service. If so, a new fee will apply.