How to Use Wireless Soil Moisture Sensors in Smart Farming

Farming Today

Farming is expected to feed the growing population and serve new consumer trends, which demand high-standard food supplies produced with sustainable methods and delivered through transparent supply chains. Despite the increasing demand, commodity prices remain low, and farmers need to control costs. That said, everyone in agriculture knows this is easier said than done.


Farming isn't just like any other business because you are dealing with the laws of nature. You don't have the luxury of balancing your revenues and costs based on clear-cut information in a confined environment, as in most other industries.

In fact, due to climate change and increasingly unpredictable weather, making the right farming decisions is becoming even harder with rising trends of weather extremes – drought, floods, and storms.

Water scarcity is critical. As agriculture consumes 69% of water globally, farmers need to find safe ways to reduce water consumption without jeopardizing crops. It's no longer possible to increase production by converting more land to farming due to irreversible ecological damages. Instead, the efficiency of existing farm fields must be improved sustainably and smartly.

How to Produce More with Less Resources?

How do you produce higher crops with better quality while reducing costs and using less water and more sustainable farming methods? How do you accomplish this profitably amid the ever-challenging and unpredictable weather and environmental conditions?

If traditional weather observations and appliances could provide the required accurate and timely information, the problem would have been all gone by now.

The Solution is Smart Farming!

Agriculture has gone through several revolutions – from the domestication of plants and animals to selective breeding, fertilization, and mechanization. The next agricultural revolution is Smart Farming enabled by measured observations, real-time data, and recorded feedback.

However, the missing link in Precision Agriculture has been the soil itself — how to bring underground phenomena up to speed with real-time telemetry, optical crop sensing, and variable rate applications. Disconnecting visible plant observations from what actually happens in the root zone leads to inadequate understanding and even incorrect conclusions.

Using Wireless Soil Moisture Sensors for Smart Farming

wireless soil moisture sensor in smart farming

At last, Soil Scout wireless soil moisture sensors expand the Smart Farming revolution to the underground.

The wireless soil moisture sensors collect accurate root zone data from below ground where the growth really takes place; sends this data to the Monitoring Service, which turns it into meaningful information for farmers who can now tackle their most substantial challenges – and improve crop productivity and quality sustainably while reducing operational costs and water consumption.

The Three-Step Process of Smart Farming

1. Measure Growth Variability and Classify Areas

Areas of a field classified based on yield.

Maximal crop growth can only occur when soil moisture is maintained within the optimal range. Any periods, even short ones, of too low or too high soil moisture conditions will immediately reduce plant growth and decrease profitability.

However, farm fields are never uniform in terms of soil type, structure, topography, or water holding capacity. These qualities can vary significantly from zone to zone. Thus, the in-field variation of soil moisture and other attributes such as salinity and temperature lead to uneven growth across a field.

Measuring the In-field Variation

A graph showing how soil moisture varies between different parts of the field

Consequently, it is pointless to measure "farm level soil moisture" using single-spot soil sensors or rain-gauges since they simply don’t provide sufficient granularity as conditions on every part of every field is different.

Regional ET models and water deficiency estimates are also only good for background information, but fall short in revealing in-field variations in root zone soil conditions where the growth takes place.

Smart Farming is all about site-specific management, and underground soil conditions make no exception. Monitoring soil moisture, temperature, and salinity continuously at multiple spots – using underground soil sensors – captures in-field variations and removes the guesswork from soil management.

But you can't afford an infinite number of devices. How can you choose optimal soil sensor locations?

Begin by Instrumenting

Taking samples with a soil scanner.

The solution may be simpler than you would expect. You have the knowledge of the best zones and problem areas within your fields, as well as something in between. Let's begin by instrumenting those.

When in doubt, yield maps and/or satellite biomass and NVDI images (e.g., Sentinel Playground), or Veristech soil scanner are useful tools for classifying different zones. Obtaining a real-time view and recorded history on how these zones behave will give you the perfect baseline to start tracking patterns and adjusting management.

2. Monitor Underground Soil Conditions with Wireless Sensors

In the end, plants need three things to grow: sunlight, water, nutrients (and, of course, CO2). Two out of three of these growth factors come from the underground through root uptake. This in mind, it is obvious that managing crop production accurately without measuring soil conditions leaves plenty of room for guesswork.

Placing the Wireless Soil Sensors

To achieve accurate and meaningful soil monitoring data, at least two sensors should be buried at different depths in each classified zone. This technique reveals the vertical profile of each measured parameter, allowing for observations on infiltration speed, drainage performance, temperature gradient, and compaction, to name some.

With this setup, you can observe the soil behavior of the various classified zones – including moisture, salinity, and temperature - and the comparison will reveal meaningful differences.

3. Determine Reasons for Poor Growth & Act

The detailed and holistic view of the underground soil conditions enables you to compare the high-yield and low-yield areas, determine the root causes of the in-field variability, and take informed actions – which is the fundamental objective of Smart Farming.

The accurate data enables you to observe patterns and seek growth limiting factors efficiently by observing draught, wetness, poor drainage, inhibited infiltration, water availability, soil compaction, and more.

Act Based on Soil Data

If you have the ability to irrigate, you can identify when to apply water and get real-time feedback to define the correct rate. In rainfed farming, zones with too little moisture can be targeted with farming actions that improve water holding, while too wet zones require activities that enhance infiltration and drainage.

While direct interventions on soil moisture may fall short or take a long time to develop, tracking daily water availability enables adjusting inputs according to the limited growth.

RELATED: How Soil Moisture Affects Crop Productivity - Download Smart Farming Research

Benefits of Wireless Soil Sensors in Smart Farming

With this three-step Smart Farming process, you can gain several benefits:

  • Improve crop production and maximize the efficiency of your fields cost effectively and sustainably by treating each zone optimally based on accurate measurements.
  • By continuously monitoring soil conditions with underground sensors, you can keep your soil under control, maintain soil moisture in the correct range and adjust your other operations accordingly, apply just the right amount of inputs at the right places at the right time, and gradually improve the soil through even better farming practices.
  • You can increase revenues while reducing operation costs, saving in fertilizer and irrigation expenses, using water more accurately and responsibly — all this aiming for higher profits!

Download the Soil Scout solution description and learn more!

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
Johannes Tiusanen

Chief Science Officer, and the inventor, and founder of Soil Scout, a farmer, and Ph.D. in Agriculture Technologies.