http://www4.uwm.edu/cehsc/community/upload/Wright_EW_BC.pdf

A research project on the relationship between worms and the pH of soil

 

http://www.ncbi.nlm.nih.gov/pubmed/23359996

Shows that a presence of worms increases levels of pH and conductivity in soil

 

https://www.agriculturesolutions.com/resources/92-the-why-and-how-to-testing-the-electrical-conductivity-of-soils

The step by step process to test soil conductivity

 

http://depts.alverno.edu/nsmt/archive/DethleuxayFahres.htm

Phosphorous levels in soil compared to worms

 

http://preparednessmama.com/jar-soil-test/

Process of how to figure out soil texture

 

http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447041&topicorder=6&maxto=10

What affects pH in soil

 

http://www.phillywatersheds.org/whats_in_it_for_you/residents/infiltration-test

Soil infiltration rate