2026/04/01 by Franziska Weinrich, Christoph Rosinger, Luca Giuliano Bernardini +2 · 1 voice
Environmental Science · Agricultural and Biological Sciences · #Soil Geostatistics and Mapping #Soil Carbon and Nitrogen Dynamics #Polar Research and Ecology
paper · doi:10.1111/sum.70221
openalex publication_date 2026/04/01 · openalex created_date 2026/05/03 · openalex updated_date 2026/06/19
ABSTRACT Soil degradation and the loss of organic carbon threaten agricultural productivity and climate resilience worldwide. Yet, practical on‐farm tools for assessing soil microbial activity, an essential indicator of soil health, remain scarce. Most available methods require laboratory infrastructure or scientific field equipment, thus limiting their use in on‐farm monitoring and in resource‐constrained regions. Here, we present a low‐cost assay that quantifies microbial respiration through the CO 2 ‐induced colour change of a pH‐indicator, evaluated via smartphone imaging. Tested across 13 sites in Eastern Austria with different land uses (conventional farming, conservation farming and field margin soils) and substrate amendments (glucose, milled alfalfa and milled straw), the method reliably captured differences in microbial activity and showed strong correlations with reference measurements ( r 2 up to 0.76). Alfalfa amendment provided consistent results without indicator saturation, making it a suitable standard substrate. Image pre‐processing (median filtering, illumination correction) further improved reproducibility under on‐farm conditions. Beyond its technical validity, the assay aligns with EU Soil Strategy 2030 objectives, offering farmers, advisors and educators an accessible tool to monitor biological soil functions, raise soil literacy and support sustainable land management.