Test your soil health IQ


I talk about soil often in this column because it affects everything we do.

Farmers use the soil to grow the crops the world needs for food. Homeowners grow vegetables and fruits to feed their families. Trees, which give off the air we breathe, are deeply rooted and fed by nutrients in the soil.

Soil is a resource that we take for granted since it is everywhere around us every day, but how much do you really know about soil? The USDA Natural Resources Conservation Service has created the following “Soil Health IQ” test, 10 questions that are sure to enhance your appreciation of this vital resource:

1. Regular tillage/plowing helps keep open pores at the soil’s surface and increases water infiltration into the soil. True of false?

2. Microorganisms in the soil generally harm plants. True of false?

3. In a teaspoon or two of healthy soil, there can be more living organisms than there are people on the globe. True of false?

4. Half of a healthy soil’s composition should be pore space that contains air, water and microorganisms. True of false?

5. Organic matter buffers the soil against big changes in moisture and temperatures. True of false?

6. Healthy soil should be allowed to rest from time to time – that is, to lie bare without growing plants. True of false?

7. Fungi are not needed for healthy plant growth. True of false?

8. Each 1 percent increase in soil organic matter can increase soil water holding capacity by 20,000 to 25,000 gallons per acre. True of false?

9. Earthworms are more abundant in tilled or plowed soil. True of false?

10. Leonardo DiCaprio wrote, “We know more about the movement of celestial bodies than about the soil underfoot.” True of false?

For question 1, give yourself a point if you answered false. Hoeing your garden or plowing your farm field destroys soil aggregates and reduces the soil’s ability to receive and hold water.

Number 2 is false. Most microorganisms are beneficial. They decompose residues, make key nutrients available to plants, and build soil aggregates. Many plants exude substances through their roots to attract these tiny organisms. That is how beneficial they are.

For question 3, give yourself another point if you answered true. Bacteria, fungi, earthworms, beetles, yeasts and more contribute to millions of species. Billions of organisms are in the ground underneath our feet.

An ideal soil composition by volume should be about 50 percent solids (45 percent mineral and 5 percent organic matter) and about 50 percent pore space. Statement number 4 is true.

Organic matter provides insulation from variations in temperature and it provides greater water holding capacity. Give yourself another point if you answered true for number 5.

The answer to question 6 is false. Having plants growing all the time allows more solar energy to be converted into carbon to feed soil microbial populations and improve soil health.

Arbuscular mycorrhizal fungi, abundant in healthy soil, have a symbiotic relationship with almost all agricultural plants. The fungi grow into the inside of plant roots to tap into the sugars and carbohydrates transported from the plant leaves. In turn, the fungal hyphae (filaments) that grow out from the roots bring soil and nutrients back to the plant. The answer for question 7 is false.

For question 8, award yourself one point for true.

The answer to question 9 is false. Tillage such as plowing and hoeing damages earthworms directly and also damages their habitat. Total earthworm populations in long term no-till fields are typically at least twice those of plowed fields.

Question 10 was a trick! The statement is probably true but was written by Leonardo da Vinci, not the actor Leonardo DiCaprio. The correct answer to this question is false.

Add up your points and if you score 8, 9 or 10 points, then you have earned the title “Soil Scholar.” For those of you who would like to learn more about soil and how to keep yours healthy, visit www.delawareswcd.org or call the Delaware Soil and Water Conservation District office at 740-368-1921.