The forthcoming EU Soil Monitoring and resilience Law aims to ensure good soil
health across Member States by 2050. The EJP SOIL research programme has provided
critical insights to support a directive is both scientifically robust and practically feasible.
Among EU countries, 19 already have a national monitoring system, so the Soil
Monitoring should build on the existing for these countries, which emphasizes the
importance of harmonization. Critical aspects in a soil health monitoring system are the
sampling design, the choice of indicators and how targets and thresholds are set.
Sampling design across a country was shown to influence the representation of
different land-uses and soil types and in-fine, the values of indicators. Regarding
indicators, a tiered approach is proposed, which balances minimum harmonized
indicators with context-specific complementary set. A set of tier 1 indicators is
proposed, for soil biology indicators, that encompasses both functional and structural
soil biology indicators. Setting meaningful targets and thresholds is another critical
dimension. EJP SOIL proposes a decision framework that includes our approaches, based
on fixed values, reference sites, population distributions, and relative change,
depending on available data and policy goals. Such a framework provides flexibility for
national implementation while supporting EU-level reporting. Finally, harmonization
with existing systems like LUCAS Soil is essential. Rather than replacing national
protocols, EJP SOIL advocates developing transfer functions and adding new co-located
sites to align datasets, preserving long-term continuity while improving interoperability.
These lessons form a strong scientific and policy foundation to guide the Soil
Monitoring Law's development and when accepted, implementation, enabling soil
health monitoring that is scalable, policy-relevant, and which is also essential and is
being developed in several EU projects, rooted in stakeholder engagement.