How many Sensoterra sensors will you need?

How many Sensoterra sensors will you need?

How many Sensoterra soil moisture sensors will you need to place in the field?

How many Sensoterra soil moisture sensors will you need to place in the field?

Having in mind that every field is unique and includes different factors, such as soil homogeneity, crop type, type of irrigation, Sensoterra decided to answer the famous question: "How many soil moisture sensors do I need to place in my field?". First, users need to answer a few questions to understand their field in terms of sensors quantification. They are:


1- Number of irrigation systems

Field measurements are necessary to characterize the irrigation system in terms of its most important parameters, to identify problems in its function, and to develop alternative means for improving the system.

Based on your irrigation type: drip irrigation, sprinkler, surface, pivot, together with how many irrigation nozzles there are in the field, users can quantify how many sensors will they need to place on the ground:


1 irrigation system = 1 irrigation equipment/head/nozzle = 1 Sensoterra sensor


For every irrigation system in the field, one sensor is recommended to be placed. The number of nozzles per field will vary with the irrigation type and/or necessity.

2- Soil texture

The soil type at your field will determine how fast and how often water should be applied to the crop. Soils are complex systems, presenting more or less heterogeneous features according to each soil texture. 

One field can present different soil textures. A given texture and quantity of soil will hold a given amount of moisture. Because of that, every field will vary on the amount of water that soil can hold, reflecting on spatial variation.


Heterogeneous fields = higher variation among soil textures = more sensors 

Homogeneous fields = fewer variation among soil textures = fewer sensors 


The higher the spatial variation, the higher the field heterogeneity, and a greater necessity to control variance in soil moisture levels.



Heterogenous fields, with more than one defined soil texture, will require more attention due to their variance in the water holding capacity.

More sensors need to be placed in the field to control variances. 

3- Crop type

Every plant requires a certain amount of water to survive. Every crop present specifications in regards to rooting size and shape, leaf size, leaf density, evaporation rates, and other many features, reflecting on different irrigation schedules. 

The higher the crop density, the greater the water you need to apply. In accordance, the greater the density, the greater the number of sensors to be placed in the field:


Higher crop density = more sensors 

Lower crop density = less sensors


 Below you can find the recommended sensor length for each crop type and an approximate number of sensors:

How many sensors do I need 

4- Satellite imagery

Satellite imagery can help users to have a birds-eye view from their fields. Image from satellites better reveals real crop size per area and volume in terms of crop-canopy density. Satellite imagery can be found on search engine tools, such as Google Earth

The denser the canopy, the more sensors users will need to place:

Higher crop density = more sensors 

Lower crop density = less sensors


In addition, in cases of an intense canopy, Sensoterra recommends the use of multi-depth sensors. Multi-depth sensors have higher antennas that can be placed on top of the canopy cover, providing better connectivity between the sensor and the gateway.


About Sensoterra

Sensoterra is a global leader in smart farming technology, providing wireless soil moisture sensors to all types of growers. The incredible spreadability of over 5,000 sensors around the world is possible due to IoT technology, established by LoRa connectivity. Sensoterra was founded in 2014, based in Amsterdam with projects in agriculture, horticulture, nature restorations, and smart cities. Robust and easy-to-install sensors come in different lengths with single-depth sensors - 15 cm, 30 cm, 60 cm or 90 cm - and multi-depth sensors, with six different depths in one sensor.

For more information please contact: [email protected]