The pathogenic prion protein readily attaches to soil particle surfaces, and the interaction between PrPTSE and some clay mineral surfaces is particularly avid. Prions exhibit limited mobility in soil columns, suggesting that in the absence of preferential flow paths or facilitated transport, TSE agents released into soil would remain near the soil surface where they are more accessible to grazing animals. Particle-associated PrPTSE molecules may migrate from locations of deposition via transport processes affecting soil particles, including entrainment in and movement with air and overland flow. The mechanisms of PrPTSE attachment to soil particle surfaces remain to be elucidated. The extent of PrPTSE interaction with natural organic matter and the influence of N-linked glycosylation and glypiation on PrPTSE attachment to soil particle surfaces warrant research. Soil and mineral particle-bound prions exhibit increased disease transmission by the oral route relative to that of the unbound agent. Enhanced disease transmission by particle-bound PrPTSE may result from altered bioavailability of soil-bound prions by animals, changes in PrPTSE conformation or aggregation state that impact TSE infectivity, or both. Research is needed to elucidate these mechanisms and evaluate the extent to which soil impacts oral TSE transmission in ruminants.
Several reports have shown that prions can persist in soil for several years. Significant interest remains in developing methods that could be applied to degrade PrPTSE in naturally contaminated soils. Preliminary research suggests that serine proteases and the microbial consortia in stimulated soils and compost may partially degrade PrPTSE. Transition metal oxides in soil (viz. manganese oxide) may also mediate prion inactivation. Overall, the effect of prion attachment to soil particles on its persistence in the environment is not well understood, and additional study is needed to determine its implications on the environmental transmission of scrapie and CWD.
Found this in an article, hopes it helps you.
If this is going on in your state, I would be concerned. Why do they quarantine farms for 5 years, if they feel there is no soil transfer??? They told us that the only place they could destroy prions, was in the digester they had in Ames, Iowa.