The old saying goes, "Soil is what plants grow in and dirt is what's under your fingernails." Funny!
Yesterday I posted a video showing how to "pull" soil cores from a home lawn and pack them up for testing by a soil lab, in this case the Merkle Lab in University Park, Pa.
Why are soil tests important every 3 to 5 years?
When soil pH is too "acidic" or "sour" (with a low pH number) nutrients already present in the soil become "locked-up" and unavailable to grass. Raising the pH with an application of agricultural lime has the same effect as applying fertilizer in some cases, since it "unlocks" plant nutrients already present in the soil.
Soil with the pH in the proper range makes future fertilizer applications more effective.
Soil test kits are relatively inexpensive with the total cost of the test kit and postage to the lab being less than $20.
The rest of the good news is that agricultural lime is relatively inexpensive and one application may be enough for several years. Powdered lime is super-cheap but the pelletized version (powdered lime turned into pellets) is much easier to handle and less messy to spread.
Soil test results will also indicate whether you should apply a dolomitic lime, which has extra magnesium, along with the calcium.
Test results usually take 2 to 3 weeks to come back from the lab and fall is considered a great time to apply lime!