Many times, memories of earlier times are tied to our senses: the taste of your mother’s apple dumplings, the crack of the bat in those childhood pickup baseball games or the feel of a well-worn basketball as you shot hoops well past dark.

For those who grew up on a farm, those memories are tied to the sights, sounds and smells of rural Indiana. Recently I ran across a social media poll: What was your favorite childhood smell on the farm — fresh mown hay or freshly plowed ground? That brought up the question: Just what am I smelling after the soil is plowed?

In 1965, American scientists determined the smell was caused by Actinomycetes, a soil dwelling bacterium which lives in warm, moist soil conditions. According to the Noble Research Institute, if your soil is cycling organic matter, it will have that fragrant earthy smell. When the soil dries up, such as after moldboard plowing, these tiny organisms produce tiny spores that we can smell.

So, why is it important to talk about why soil smells? It serves to remind us that soil is not just dirt. Soil is a dynamic ecosystem, full of millions of various organisms that work in harmony together. And not only are they working, but they are also working for you, and you don’t even have to pay them or send them a 1099. They only ask that you provide the support system they need to thrive, and they will do the rest. They will work hand in hand with your plant roots to provide nutrients your crops need to produce healthy plants resulting in a bountiful harvest.

Cornerstones of healthy soils

What is that support system that the soil organisms desire? It’s all about the four cornerstones of soil health:

1. Cover. Keep the soil covered to protect it from erosion and excessive heat, and provide a food source for macro-organisms such as earthworms.

2. Plant diversity. Provide diversity above ground so there is diversity below ground in different kinds of roots stimulating the diversity of the life that we cannot see in the soil.

3. Limited disturbance. Limit soil disturbance. Tillage destroys the balance of organisms in the soil and reduces their effectiveness in making nutrients available for crop use.

4. Living roots. Keep living roots all year long, using both cash crops and cover crops. The underground biology thrives when something is growing, keeping the soil alive all year long.

Notice that these four cornerstones do not involve moldboard plowing. We may not get the smell of freshly plowed soil, but we know that the bacteria and soil fungi are still working for us. Actinomycetes, according to internet sources, are the bridge between bacteria and fungi. They are both aerobic and anaerobic, working with or without oxygen. All microbes are important to the soil.

Soil is that all-important resource we tend to take for granted. If we want to have healthy grandchildren, we must continue to produce healthy food for them to eat. We can only do that with a healthy soil to produce that food. To start your journey toward healthier soil on your farm, contact your local soil and water conservation district or Natural Resources Conservation Service office for more information.

Donovan is a district conservationist with the Natural Resources Conservation Service. He writes on behalf of the Indiana Conservation Partnership. Tom J. Bechman contributed to this article.