Save our soils: harmonising data essential to success of Horizon Europe research mission

Next month will see the launch of the EU Soil Observatory, a new programme for monitoring European soils, which will merge information from the EU’s Copernicus earth observation satellites and field assessments from the European Soil Centre, to create a single database on the health of soils across Europe.

The database will lay the foundations for the EU mission on soils, one of the five ‘moonshot’ research programmes to be funded as part of Horizon Europe. Today 60 – 70 per cent of Europe’s soils are out of condition. The soils mission aims to make 75 per cent of EU soils healthy by 2030, but without standardised reporting it will be impossible to track progress.

The success of both the observatory and the mission depends on member states stepping up reporting on soil health, said Lachezar Hristov Filchev, the head of Remote Sensing at the Space Research and Technology Institute at the Bulgarian Academy of Sciences, who is a member of the soils mission board. “If we destroy the soils, we will never be able to get them back. That is jeopardising our own existence,” he said.

“Closer co-operation on the matter and engagement is needed to make sure this process is successful,” said Filchev. “Unfortunately, this type of data is not complete in spatial, temporal, and thematic terms all across the EU member states. Therefore, there should be some effort on harmonising the key datasets for the soil health assessment through in-situ monitoring networks.”

The mission board that has drawn up the proposal for the programme made the estimate that 60-70 per cent of European soils are unhealthy after conducting a meta-analysis of individual reports on the health of European soils.

One reason why data is not harmonised is because there is no directive asking member states to report on soil health. It is all voluntary. “You have to report on the quality of your water, on biodiversity, yet there is no requirement to report on soils,” noted Bridget Emmett, a mission board member who is head of Soils and Land Use science at the UK Centre for Ecology and Hydrology.

Without comprehensive, harmonised data, it is impossible to know whether Europe is on track to salvage its soils. “We already had some discussions, and everyone agrees that whatever we want to achieve with regard to soil health, we have to assess it,” said Filchev.

Onsite collection of data is expensive and requires equipment and expertise. “The hardest parts are the national monitoring systems,” said Filchev. “This requires investment, and it will be hard to convince them. Unfortunately, within member states, we have less and less monitoring.”

A further difficulty is the lack of a common definition of what constitutes soil health. Soil may be healthy in one way but not another, says Arwyn Jones, an expert at the Land Resource Management unit at the EU Joint Research Centre (JRC).

To streamline the process, the mission board has drawn up a list of eight indicators for measuring soil health, ranging from the presence of pollutants and excess nutrients, to forest cover and landscape heterogeneity. The goal is to keep the indicators minimal to allow the JRC to quantify soil health across Europe, said Filchev.

Earth observation

Currently, a large percentage of EU soil data comes from the space programme Copernicus. Satellites can measure indicators including vegetation, how much of the soils are covered to reduce loss of nutrients and loss of soils in urban areas.

However, satellites can only look at the surface, yet soils are three dimensional and change with depth. “The challenge with the use of remote sensing is the fact that it is using reflected energy to measure several things that are traditionally measured using sophisticated instruments in laboratories,” said Jones. ”So, you have to make that leap between the reflected energy that is measured by the sensor on the satellite and the physical property within the soil.”

Technology is fast progressing however, and shortly, imaging spectrometers will be coming on stream that will measure the carbon content of soil and some pollutants.

The JRC has also assessed the use of satellites to map what crops are growing in what fields in Europe, data the EU does not have currently. That could be used to work out what pesticides and fertiliser regimes are used where, for example.

Such information cannot give a definite answer on how much soil is unhealthy, but it can help identify at-risk areas and how the land is used. “Satellite data gives you a large view of the landscape, while it is very expensive collecting soil samples directly,” said Jones.

All this data is already being used by the European Environment Agency and the JRC. Now, it will also feed into the EU Soil Observatory.

The new observatory will also use data from the European Soil Centre and the JRC’s existing models of erosion and other indicators. It is also hoped to build on activities taking place in member states, and to supplement in situ data collection, said Jones.

Soils are key to preserving biodiversity, reducing pollution, growing the circular economy, and farming, all of which are part of the EU green deal. Given this, demonstrating European soils are rejuvenating would be a clear indicator green deal policies are delivering. “We need to able to demonstrate that these policies are working,” said Jones. “If we reduced pressures on soil and soil degradation, that would mean we are making progress.” 

The soil mission plans to identify and map soil needs, structures, and funding mechanisms for research in the next few years. All of this will feed into the new observatory.

The board hopes to start mission monitoring activities from 2022 and support further development of monitoring systems in 2022 - 2024. To help the mission do this, member states will have to harmonise soil monitoring. “They are reluctant to develop new monitoring mechanisms. It won’t be an easy task,” said Filchev.

The soils mission handed over its proposal on how to do this to the European Commission in September. Currently, the commission is assessing the plans and assigning a budget. The mission board will then re-evaluate its plans accordingly.