Question: I keep hearing the terms “healthy soil” and “soil health.” What does it mean for a soil to be healthy? Does it just mean the soil is free from pollutants?
Answer: Soil health is a difficult concept to describe because unlike our human bodies where blood pressure and body temperature can tell a doctor a lot about our health, there are no comparably simple tests to perform that will tell us if a soil is “healthy.”
The pursuit of soil health used to focus simply on lessening soil compaction or increasing fertility (nutrient levels). But the concept has evolved in recent years and gotten more complex.
–Answered by Gary “Pete” Peterson, Colorado State University
Soils Matter, Get the Scoop! 
Cornell has some great info on Soil Health as well. http://soilhealth.cals.cornell.edu/ The sprinkle infiltrometer for measuring aggregate stability is super cool!
Thanks for sharing the information!