Neal Kinsey has heard some people say that the purpose of a soil test is just to point you in the right direction.

“I don’t think that’s good enough,” says the Charleston, Mo., agronomist and fertility expert. “You don’t want to be pointed in the right direction, you want to know what to do.”

That starts with taking a good soil sample, which means taking it “in such a way that it truly represents the area in question.” If a field has a lot of variation — enough to justify fertilizing different areas separately — then those areas need to be sampled separately.

“If you don’t take the sample right, the answer you get is going to be wrong.”

Think of fertilizing like buying a car, Kinsey says. You can buy a cheap, simple car, or you can buy an expensive fancy sports car. Both will get you where you need to go, but you might end up spending a lot more on features you don’t actually need or skimping on features you should have spent more on.

“You can spend a bunch of money on fertility,” he says. “But what you want to do is put the money where it makes the most difference. Until you have a soil test that will give you that kind of guidance, how do you know what to do?”

Highlighting specific lines from two real-life soil tests, Kinsey explains how an accurate soil test can provide guidance on exactly what is needed to…