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https://taat.africa/gov/technologies/chameleon-sensor-soil-moisture-monitoring-sensor
Simple signals, smarter farming
The Chameleon™ Soil Water Sensor is a device used to measure and monitor soil moisture. It works by mimicking how plants experience water in the soil, measuring the effort (tension) roots need to extract moisture. The sensor is designed to be accurate within the range where most crops are sensitive to water stress. Since it measures tension rather than moisture content directly, it can be used in any soil type without calibration.
This technology is not yet validated.
Adults 18 and over: Positive high
Everyone can use it without complex training.
The poor: Positive high
It is not very expensive
Under 18: Positive high
Youths can use it easily. It requires no complex training
Women: Positive high
Women can use it easily. It requires no complex training
Climate adaptability: Highly adaptable
It is adaptable to different tropical climates
Farmer climate change readiness: Significant improvement
It improves irrigation water application
Biodiversity: Positive impact on biodiversity
Carbon footprint: Much less carbon released
Environmental health: Greatly improves environmental health
Soil quality: Improves soil health and fertility
Water use: Much less water used
It enables efficient water application and water productivity
1. Over-irrigation: Excess water washes away fertilizers, making them less effective and increasing input costs. It also leads to higher fuel and labour expenses for pumping and applying water. Over time, soils may become waterlogged, and yields can drop instead of improving.
2. Under-irrigation: Too little water causes plants to go into water stress, which slows growth and reduces yields. Farmers often cannot tell how dry the soil really is until crops are already damaged.
3. Soil degradation and salinization: Applying too much water over long periods can cause nutrient leaching and build-up of salts in the soil. This damages soil structure and fertility, making it harder to sustain productive farming in the long term.
4. Pests and diseases: Excess moisture creates conditions where fungal diseases, root rots, and insect pests thrive. This increases the need for pesticides, raising costs and potentially harming the environment.
5. Inefficient labour use: Traditional irrigation often requires time-consuming manual watering, which ties up valuable labour. When water is applied unnecessarily, it wastes not only water but also human effort that could be used for more productive activities, like weeding or harvesting.
6. Lack of reliable information on soil water status: Most farmers rely on guesswork or observation (e.g., how soil looks or feels), which is inaccurate. This leads to inconsistent practices and reduced efficiency.
The Chameleon™ Soil Water Sensor is a simple, low-cost, and innovative tool that helps farmers monitor soil water availability directly in the root zone. Using colour codes (blue = wet, green = good, red = dry), it mimics how plants experience water stress and shows when to irrigate. Unlike other sensors, it works across all soil types without calibration, is durable, and easy for farmers to use. By guiding irrigation more precisely, the Chameleon prevents over-irrigation (wasting water and nutrients) and under-irrigation (causing crop stress and yield loss).
To integrate the Chameleon into agricultural projects, please consider the following key steps:
Starter kits cost approximately USD 200 (Wi-Fi Reader + sensor array) or USD 66 (Chameleon Card + 3 sensors).
Each sensor lasts 2–4 years, and multiple depths (20, 40, 60 cm) may be used per field to track water movement.
Plan for supply, shipping, import clearance, and distribution to ensure timely delivery to project sites.
Account for licensing and sourcing from authorized manufacturers (e.g., RIEng in South Africa).
Train extension agents and farmers on sensor installation, reading colour codes, and interpreting results.
Provide ongoing support and simple training materials to ensure adoption and continued use.
Develop farmer-friendly materials such as posters, demo videos, and radio messages to promote awareness.
Use colour-coded examples to show benefits and guide irrigation decisions.
Place sensors at key depths in the root zone (e.g., 20 cm for shallow crops, 20–40–60 cm for deep-rooted crops).
Proper installation ensures reliable readings and accurate irrigation scheduling.
Combine Chameleon use with improved crop varieties, nutrient management, precision irrigation, and digital advisory services for maximum impact.
Collaborate with research institutes, extension systems, NGOs, and agro-dealers for training, technical support, and scaling.
Integration into national irrigation or climate-smart agriculture programs will expand adoption and sustainability.
The Chameleon™ Soil Water Sensor empowers farmers to make better irrigation decisions, saving water, protecting soils, and improving yields. For governments, adopting this tool strengthens food security, supports climate adaptation, and contributes to sustainable agricultural development goals.
Typical lifespan of a sensor
Open source / open access
| Country | Testing ongoing | Tested | Adopted |
|---|---|---|---|
| Ethiopia | –No ongoing testing | –Not tested | Adopted |
| Ghana | –No ongoing testing | –Not tested | Adopted |
| Lesotho | –No ongoing testing | –Not tested | Adopted |
| Malawi | –No ongoing testing | Tested | Adopted |
| Mozambique | –No ongoing testing | Tested | Adopted |
| South Africa | –No ongoing testing | –Not tested | Adopted |
| Tanzania | –No ongoing testing | Tested | –Not adopted |
This technology can be used in the colored agro-ecological zones. Any zones shown in white are not suitable for this technology.
| AEZ | Subtropic - warm | Subtropic - cool | Tropic - warm | Tropic - cool |
|---|---|---|---|---|
| Arid | ||||
| Semiarid | – | |||
| Subhumid | – | – | ||
| Humid | – | – | – | – |
Source: HarvestChoice/IFPRI 2009
The United Nations Sustainable Development Goals that are applicable to this technology.
Soak the sensors in water before installation (they are shipped dry and need to be “activated”).
Check that they turn blue when wet.
Choose spots in the field that represent average soil and crop conditions (not unusually dry or wet patches).
For drip irrigation, place sensors halfway between the emitter and the edge of the wetting pattern (not directly under the dripper).
For sprinklers, ensure the irrigation system is uniform before installing.
Use a sharpened 20 mm pipe to make a hole in the soil.
Feed the sensor wire through the pipe.
Insert the sensor into the hole to the desired depth (e.g., 20 cm, 40 cm, or 60 cm).
Backfill and press the soil firmly around the sensor to ensure good contact.
Shallow-rooted crops: 10–20 cm.
Deep-rooted crops: 20–30 cm.
Multiple depths (20, 40, 60 cm): to track how water moves through the root zone.
With Chameleon Card (manual):
Hold down the button on the card.
Insert the sensor’s two wire ends into the slots on the card.
Read the LED colour:
Blue = Wet
Green = Moist (optimal)
Red = Dry
With Wi-Fi Reader (digital):
Connect the reader to the sensor array.
It logs data automatically (every 2 hours) and uploads to the VIA platform via Wi-Fi or mobile phone.
Blue → No irrigation needed unless weather is very hot.
Green → Best time to irrigate for most crops.
Red → Soil is too dry; plants are under stress.
Replace the battery (CR2032) when the red light flashes.
Keep the card dry and clean its contacts if needed.
Sensors usually last 2–4 years, but replace if they stop turning blue after irrigation.
Last updated on 2 October 2025
This technology can be used in the colored agro-ecological zones.
Chameleon Sensor: Soil Moisture Monitoring Sensor
https://taat.africa/gov/technologies/chameleon-sensor-soil-moisture-monitoring-sensor
Last updated on 2 October 2025, printed on 22 November 2025
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