Development of a composite index for assessment of soil compaction impacts on ecosystem services in agricultural systems

Soil compaction of agricultural systems due to the passage of heavy machinery persistently impairs the soil physical, hydrological, and biogeochemical functioning. Despite the existence of numerous studies on the influence of compaction on soil and plant characteristics, we lack studies translating such impacts into soil-related ecosystem services. Therefore, we aimed to develop five indices of compaction impacts on ecosystem services related to soil, including fresh water supply, food, feed, and fiber production, microbial habitat provision, climate regulation, and water purification. First, we selected the most appropriate soil quality indicators for each ecosystem service based on literature data and expert knowledge. Second, we scored each indicator using the fuzzy logic method and standardized scoring functions. Third, we summed the indicators and divided them by the number of the indicators to achieve a total index for each ecosystem service. Finally, we combined the five individual indices to attain a composite index for the soil-related ecosystem services. We validated the developed ecosystem services indices using experimental data of soil compaction impacts. The results showed that the five indices and the composite index were able to detect the impacts of soil compaction on the investigated ecosystem services. We advocate the use of such indices or composite index to assess how soil compaction interferes with the delivery of soil-related ecosystem services in agricultural systems.