This is a yard I’ve worked on for about 2 years.
It is primarily KY bluegrass
High PH and High CEC (7.8 and 18)
When we started I could hardly get a soil probe in 4inches.
2 years later - working to balance saturations, adding Vitalize Micros, foliar treating with Vitalize Fish Fert+Humics, and Seed Feed and Spectrum+Myco on the seed when over-seeding and we have topsoil!
That short of a period, in a monoculture and we are making things happen.
Now imagine how I fast we can make a change using high diversity like the 1-2 system.