Our agricultural P input rate lies within the high end of the global P application spectrum (Potter et al., 2010). In most of the US corn belt and crop lands in Europe and Asia, annual P application rates do not exceed 0.004 kg m− 2 (Potter et al., 2010), which AZD1080 substantially less than 0.014 kg m− 2 at our agricultural site. The P application rate used here is not, however, an unusual local phenomenon and ranks within the top quartile of P surplus (0.013–0.084 kg P ha− 1) in the globe and is typical of the coastal US (MacDonald et al., 2011). The areas under such high level of P surplus cover ~ 10% of cropland areas but are responsible for ~ 45% of total global P surplus (MacDonald et al., 2011). The geochemical mass balance approach helps us to address how mycelium residual P, which accumulates in soils (Sattari et al., 2012), compares with pre-agricultural weathering losses and biological recycling of P.