The soil sensor, the smart sensor that measures heat and drought in 5,000 gardens, parks, nature reserves and fields, was developed by TOMST. A small Czech company, world famous among microclimate scientists and, thanks to the citizen science project CurieuzeNeuzen in de Tuin, also in Flanders, Belgium. 

The CurieuzeNeuzen soil sensor is based on the existing TMS-4 sensor from TOMST (you can read all about that sensor in this scientific publication). The big – and only – difference is that the CurieuzeNeuzen “lawn dagger”, as it is affectionally called, is connected to the Internet of Things via Orange’s narrowband 4G network. With the old TMS-4 sensor, researchers retrieve the data manually with a cable. 

Precisely because these sensors are so indestructible, my wife’s colleagues, who work for the Czech Academy of Science, became interested in the devices. They were looking for a sensor to measure temperature in natural areas. That’s where the idea came from, together with colleagues from the Department of GIS and Remote Sensing from the Czech Botanical Institute, for the TMS: an indestructible sensor that could withstand extreme temperature fluctuations, with thermometers at three points. 

So the reason TOMST ended up in climate science was rather accidental? 

TOMST: Indeed, it was more of a side project for us. At the time, 2008, we had a big project going in the UK with a big supermarket chain. That project was very profitable but also very stressful. The soil sensor was more of a hobby. At the time, we only asked our university colleagues to reimburse us for the cost of parts. 
 

Was there also commercial interest in your climate sensors from the outset, or was it mainly from non-profits and universities? 

TOMST: Most of our customers are universities and scientists. For scientists, a sensor that always measures in the same way is ideal. That way, scientists can always replicate their experiments. Also, it is usually less of a problem for scientists if they have to wait a few months before they can retrieve their data. 

Commercial organisations often see things differently. In Dubai, for example, they would be very interested in sensors that would tell them remotely that the soil is dry and the newly planted palm trees need water. Our current sensors can’t do that yet. 
 

So before CurieuzeNeuzen contacted you, you were already playing with the idea of making the soil sensor wireless? 

TOMST: That’s right! We investigated the possibilities, but ran into a major problem. Our TMS sensors can last for years on one battery and we absolutely want to keep this strong point. This is not possible with, for example, Bluetooth, because it wouldn’t work at as much of a distance as necessary here. 

Wireless micro-climate sensors only recently became possible with the development of the narrowband 4G network? 

TOMST: Narrowband was indeed one of the first solutions to connect our sensors wirelessly. The advantage of 4G is that it is an existing network, so there are already transmitters everywhere and you never have to send data too far. The infrastructure is there; you don’t have to build a new network. 

Narrowband 4G uses very little energy and yet can process more data than, for example, SIG Fox, which we were also thinking about earlier (SIG Fox is another network technology for IoT, ed.). With narrowband, we can guarantee that one soil sensor can send data every day for eight years on one battery charge. 

You are a relatively small company, what was the first reaction when CurieuzeNeuzen contacted you with the request to develop and produce 5,000 4G sensors? 

TOMST: It was a very intense period. Connecting TMS to the Internet of Things would have happened anyway, only CurieuzeNeuzen accelerated the process enormously. At the beginning we were quite stunned by the request, producing 5,000 ordinary TMS-4 sensors is quite a challenge in itself, let alone developing a whole new 4G model. 

Because the corona crisis had us worried about the future of our business, we took up the challenge anyway. The chips of our sensors are entirely made in the Czech Republic. Our partner can only produce a certain number per week. So we knew that it was going to be a very tight deadline to get everything done in time. Despite COVID, it was a very busy year! 

What was Orange’s role in the development of the 4G radar band? 

TOMST: Orange provides the network to which the sensors are connected in Flanders. Their role was therefore essential. Corona provided an additional difficulty in developing a soil sensor connected to narrowband 4G. We were not allowed to leave the country, so we could not go and test it ourselves in Belgium. We hope that when the vaccination campaign gets underway, we will soon be able to come to Belgium for further testing. 

Jonas, you are scientifically responsible for CurieuzeNeuzen, what do you think the development of the TOMST soil sensors means for microclimate science? 

Jonas Lembrechts: The development of the TMS-4 by TOMST and the colleagues from the Czech Institute of Botany has meant a lot for the maturing of microclimate science as a scientific discipline. Before this, every researcher used a different sensor. Since TOMST introduced the TMS-4 to the scientific community, it is much easier to compare each other’s measurements. The low price also allows us to work on a larger scale much more quickly. 

A global microclimate network, parallel to existing weather station networks, is coming ever closer thanks to the TMS-4. Real-time data will accelerate this even further, because it will also interest commercial players. The Czech Republic is a global model for microclimate science. The Czech Republic was I think the first to have such a network covering the entire country. It would be fantastic to be able to apply this approach elsewhere across the globe. 
 

Partly due to our partnership with De Standaard, CurieuzeNeuzen gets a lot of press attention in Belgium. Was this also picked up in the Czech Republic and did you also get recognition in your own country? 

TOMST: Not at all actually, or we didn’t notice it because we were so busy (laughs). Because we mainly supply to universities and scientists, we don’t really need it. Scientists publish papers about their research with our sensors, so we have a certain notoriety within the scientific community. We can only be grateful for that. 

We are often asked if the ‘4G lawn dagger’ will become commercially available. 

Jonas Lembrechts: After completion of the research, we are going to work with iFlux (a spin-off of the University of Antwerp and VITO, ed.) to see how we can commercially deploy the soil sensors that remain. In the first instance, we are aiming at farmers, horticulturists and city councils. 

TOMST: We plan to bring the 4G sensor to the market, but the biggest problem is the network. At the moment, there is no roaming specifically for narrowband, i.e. we have to find a different provider for each market in Europe or elsewhere in the world and install different SIM cards in the sensors. We are still investigating how we can tackle this problem. We are currently thinking about virtual operators. The 5G network is gradually being rolled out, which also creates new opportunities for us. 

Due to a global chip shortage, we currently have to wait a long time for the IoT modems of our sensors. Ideally, we will bring a narrowband sensor to market in the spring of 2022. 

More information on CurieuzeNeuzen in de Tuin: curieuzeneuzen.be