When it comes to knowing what’s in your no-tilled ground, soil chemistry has traditionally received the most attention. That’s because it’s considered easiest to change by doing a soil test and applying fertilizer and lime, maintains Mark Flock.

The soil scientist and agronomist at Brookside Laboratories in New Knoxville, Ohio, finds no-tillers enhance the biological and physical components of soil as well as the chemical side by increasing organic matter and soil structure. The key is to watch and balance all three of these soil components.

He says no-tillers can determine where yields will vary by making good soil maps of fields and sampling different treatable areas. There are several ways to sample and map your no-till fields.

1. The first is a general approach — taking a soil sample at the edge of a field. But this doesn’t tell you anything about the chemical, physical and biological variability of the field.

2. Grid sampling provides a lot of information, but is so expensive that many no-tillers only do it every 5 or 6 years.

“Once you grid a field, you’re going to make recommendations on that map for 5 or 6 years,” says Flock. “This could be a problem if you have a sampling error or the lab didn’t do a good job of analysis.”

3. The soil scientist prefers sampling and mapping by zone. If he were a no-tiller, Flock would divide fields into zones, the size of which would depend on the amount of chemical and physical…