Selecting Promising Soil Quality Indicators for Monitoring Soil Management Effects Based on 10 European Long‐Term Field Experiments

ABSTRACT Background : Soil quality can be measured through soil quality indicators that reflect soil processes. Aim : The aim of this study was to (1) identify a limited set of soil quality indicators that are most sensitive to agricultural soil management and that are widely applicable regardless of pedo‐climatic conditions, and (2) link common analytical soil quality indicators to near‐infrared spectroscopy (NIRS) measurements as a potential high‐throughput approach to assess soil quality. Methods : We assessed the sensitivity of analytical, field, and visual soil quality indicators to tillage (conventional inversion vs. reduced) and organic matter addition (high vs. low) and their interaction with soil texture in 10 long term field experiment across pedo‐climatic zones in Europe. Results : Reduced tillage and high organic matter addition had a positive effect on soil quality parameters, consistent across different European pedo‐climatic zones. Total organic carbon, particulate organic carbon, plant available phosphorus and potassium, total nitrogen, microbial carbon and nitrogen, and penetration resistance were the most sensitive indicators and represent four soil functions: Organic matter cycling, nutrient cycling, habitat provisioning, soil structure maintenance. Total organic carbon and total nitrogen measured with NIRS were well correlated with their corresponding analytical methods, highlighting the promising nature of this methodology. Conclusion : The current study presents a limited set of promising soil quality indicators for monitoring the effect of tillage and organic matter addition. This selection should not be interpreted as a fixed minimum data set and future studies should strengthen the use of these indicators by developing interpretation schemes that take into account data from specific pedo‐climatic zone and land use characteristics.