Unlocking Secrets of the Soil

By Maggie McCormick, Phase I Fellow

“Keep soil covered. Minimize soil disturbances. Maximize living roots. Energize with diversity.”

These four phrases were the mantra for our workshop last week with USDA-NRCS State Cropland Agronomist, Chris Lawrence. Following these principles will aid you—whether you are a farmer, gardener, or simply a soil enthusiast—in maintaining healthy soil.

Keep Soil Covered

Covering soil, whether it is with plants or mulch, reduces the amount of erosion and runoff that can occur after a large rain or wind storm. This means an increased amount of soil, and most importantly the top layer of organic matter, is preserved, meaning healthier soil and less runoff. We witnessed the impact of covering soil during a large rainfall event with a demonstration.

A rainfall simulator over 5 plots of soil—1 is bare, compacted soil, 2 is compacted soil covered in hay, 3 is non-compacted, healthy soil, 4 is compacted soil covered in grass, and 5 healthy soil covered with grass)

After the rainfall, you can see the amount of runoff and sediment captured from each plot. The last plot, with healthy, grass covered soil, had far less runoff and sediment loss than the other plots.

Minimize Soil Disturbances

Disturbing the soil, through practices such as tilling, can be extremely detrimental to soil structure and health. In the short term, tilling will loosen and aerate the soil, release nutrients and activate living organisms in the soil. However, in the long-term tilling has many negative effects including erosion, loss of organic matter, compaction, nutrient depletion, and loss of living organisms.

In this experiment, soil from two adjacent plots of land was collected. On one plot of land (the soil on the left), tilling was a regular practice. On the other plot of land (the soil on the right), tilling was not common, and the ground remained covered year-round. The untilled soil maintained its structure when submerged in water, and absorbed large amounts of water. On the other hand, the soil that was tilled frequently, dissolved in water, and allowed water to pool on its surface, which would lead to runoff

Maximize Living Roots

Increasing the quantity, type, and amount of time that living roots are present in the soil will greatly increase soil health. Roots aid in maintaining soil structure, which in turn reduces erosion and preserves soil nutrients.

Energize with Diversity

This last point includes increasing diversity of crops, animals, and enterprises. Keeping a diverse use of land minimizes repeated negative impacts on the soil, thus keeping it healthy!

Ultimately, these 4 guiding principles of soil maintenance increase soil organic matter. Organic matter increases water retention, nutrient availability, and soil structure, all of which in turn creates healthy soil.