I talked about this blog post: https://www.asianturfgrass.com/post/potassium-reserve-in-the-soil/

The Dest and Guillard article about the bentgrass grown in eight different sands is available at https://opencommons.uconn.edu/cgi/viewcontent.cgi?article=1017&context=plsc_articles

Bier et al. on the six year study with more Microdochium where K was applied, and no response to added K, is at https://doi.org/10.1007/s11104-018-3765-8

Find out more about soil tests with ATC at https://www.asianturfgrass.com/project/soil-tests/