The aim is to develop soil sensors that provide information on soil nutrient content, moisture levels and temperature.
In crop production soil fertility is essential. In sustainable farming systems is important to minimize nutrient losses, help plan right timing for cultivation, and reduce soil trampling. In Estonia, the conditions for nutrient leaching are favorable, because the amount of precipitation exceeds evaporation by about 1.5 times. Soils are often saturated with water in spring and are sensitive to trampling. Optimal soil moisture helps to prevent excessive compaction.
The aim of the innovation activity was to develop a prototype sensor and data exchange for measuring the electrical properties of soil with digital output, which would provide dynamic data on the following soil parameters:
- soil salinity (nutrients) content
- volumetric soil moisture
- soil temperature
Practical knowledge on soil conditions help farmers schedule fertilization, tillage and sowing.
The sensors are wireless and specifically meant to be installed underground. The sensors are able to transmit data through soil, clay, ice, snow and even stones, reaching 4 metres deep underground.
The sensors enable to obtain information on soil conditions after every 20 minutes, 24 hours a day, and 365 days a year, which makes it possible for agricultural producers to make informed decisions and act sustainably.
Development process and prototype soil sensors (a,b) was carried out in collaboration with SoilScout OY in Finland. These wireless soil sensors, fueled with solar power were integrated at Rõhu base station of Estonian Universtity of Life Sciences (c,d).
- The sensors provide continuous information on soil moisture, salinity and temperature throughout the year. The data is conveniently transferred from the field to the server.
- Soil sensors are very good at detecting changes in soil temperature and relative changes in soil moisture over time, but accuracy is not always sufficient to estimate absolute values.
- The sensitivity of the sensors to detect salinity values depends on their installation. In order to record salinity data, the sensors must obtain good contact with the solid phase of the soil.
- The addition of the solar panel is important due to distance between the soil sensors and the receiving antenna.
- Additional data need to be collected to provide accurate fertilisation recommendations.
On the basis of the information obtained, it is necessary to further develop the accuracy of soil sensors and to perform additional measurements and calibrations on different soils. In future, it will be possible to connect the data with a GIS server
Innovation activities for the development of prototype soil sensors were carried out in the framework of measure no 16 “Cooperation” of the Estonian Rural Development Programme 2014-2020. The budget of the innovation activity was 60 000 € (project period: 06.03.2017 – 31.08.2020).
Soil Scout OY – Jussi Sirkiä, Johannes Tiusanen
Estonian University of Life Sciences – Alar Astover