Improving soil health starts with minimal disturbance and keeping the soil covered as much as possible, but the real way to jump start soil health is to keep plants growing throughout the year to feed the soil.

Adding cover crops to a rotation increases root growth time from one third of the year with traditional row crops to nearly two thirds of the year with the addition of covers. To understand why this is important, we need to understand the soil food web.

As plants grow, there is a symbiotic and parasitic relationship between plant roots and bacteria that feed on simple carbon sources. These bacteria can reproduce 5 billion offspring every 12 hours providing a food source for larger soil microbes.

As plants grow and their roots reach new areas, the bacteria increase exponentially.

In addition, fungi follow these root channels and create glomalin or the soil glue, the building blocks of air and water channels.

Mycorrhizal fungi carry nutrients to the plant roots as they act as root extensions branching out through the soil, feeding and sharing the nutrients with the plant roots.

Fungi also feed on larger more complex carbon, breaking it down into simple forms for bacterial decomposition. There can be miles of fungi hyphae in an acre. As these fungi branch out, the bacteria populations increase with them. Furthermore, a healthy fungus population helps control many harmful fungi that can attack crops.

While the previous two feed on plant material, protozoans and nematodes feed on bacteria and fungi mineralizing them for plant uptake.

On average, protozoans consume about 10,000 bacteria per day. Bacteria weigh about a ton per acre carrying a 5/1 C: N ratio providing about 20 pounds of nitrogen that can be used by crops and soil microbes.

Therefore, planting a two crop system of corn and soybeans does not improve soil like a rotation that includes a long season cover crop.

Most of the microorganisms in the soil move very little during their lives, and if food is not present, they cease to exist.

The larger, more mobile organisms like nematodes have a harder time locating food sources and converting that to nutrients the crop can use.

Planting cover crops with large fibrous root systems that grow late into the fall and early in the spring can significantly increase microorganism populations.

By planting a cover crop each year, you continually build the microherd allowing for faster residue breakdown and better water and air infiltration.

Because this ecosystem follows a predator/prey model, significant decreases in food sources cause prey populations to rapidly decrease, subsequently crashing predator populations. Once food sources return, populations rebound but this can take years.

Andy Gaver is a conservationist with the USDA Natural Resources Conservation Service in Butler County.