Soil health tests often use sensitive indicators, but their reliability after long-term storage is unclear. Using air-dried archived soils from a cover crop experiment, we found that three years of storage nearly doubled water-extractable organic carbon. Similar water-extractable organic carbon patterns across different long-term agricultural experiment sites show that storage can distort concentrations, so archived samples should be interpreted with caution.

The first report of the field deployment of a new soil sampling device to investigate phosphorus (P) fertiliser strategies. The approach was combined with X-ray fluorescence microscopy to produce 2D spatially-resolved P availability maps to visualise distinct differences between new and conventional P fertilisers. This technique shows great potential for optimising P application and material sciences development; potentially leading to improved productivity and more sustainable P fertiliser use.