European Journal of Sustainable Agroecosystems

Background: Soil enzymes are biological activators that are secreted by microorganisms, root systems of plants, and soil fauna, causing breakdown of organic matter and cycling of C, N, P, and S elements in agroecosystems. Their ability to respond to management practices quickly and their activity preceding measurable alterations in physical and chemical properties of the soil itself makes soil enzymes a popular choice as an efficient indicator of soil quality and sustainability of agroecosystems. Aim: The paper presents the findings described in peer-reviewed articles published during the period between 2015 and 2025 and evaluates the effectiveness of soil enzymes as an indicator of agroecosystem sustainability across different management system and climatic contexts, as well as pollution gradients. Information sources: A systematic search for information in Scopus, Web of Science, PubMed, and Google Scholar databases resulted in 1,824 articles with 33 studies and four famous references selected according to a PRISMA-based procedure. Dehydrogenase activity, β-glucosidase activity, urease activity, and acid and alkaline phosphatase activity showed consistent increases when conservation tillage, organic amendment, and biochar management systems were compared to conventional tillage and systems without any treatment. Enzyme activity was found to be inversely proportional to the degree of heavy metal contamination and nitrogen deposition in the soil. In this way, the stoichiometry of the enzymes was found to serve as the integrative framework that connects the limitation of microorganisms in terms of nutrients with ecosystem functioning despite the fact that threshold values depend on soil type and climate. Research gaps: Although there is a high need to standardize the methodology at the level of the procedure, carry out long-term multi-site validation of the results, apply molecular and omics-based technologies and develop indices that would help convert enzyme activities into relevant and sensible measures of soil health, these tasks still have to be tackled.  Conclusion: The soil enzyme activity seems to be a scientifically sound indicator of agroecosystem sustainability, however, in practice, its predictive power is limited since one requires contextualized data, standard procedures, and combination of enzymatic indices with other measures.