Soil as a Resource (Study Guide Questions)

Question 1

What are the six “crucial ecological roles” of soil in our environment?

Answer 1

1. medium for plant growth
2. regulates water supplies
3. recycles nutrients and carbon
4. modifies atmosphere
5. habitat for soil organisms
6. engineering medium

Question 2

What essential needs for plant growth are supplied by the soil?

Question 3

Which six macronutrients are obtained primarily from the soil?

Question 4

How does the soil contribute to the regulation of water supplies?

Question 5

How is the soil important in life (and death) of many organisms?

Question 6

Why is knowledge of soil properties critical when considering building on or in the soil?

Question 7

What is regolith and how is it related to soil?

Question 8

There are six soil master horizons, each designated by a different capital letter. The O horizon is a highly organic layer that forms at the soil surface, e.g., under forest vegetation. The R horizon is the bedrock horizon. What are the other four master horizons, and what are the features that distinguish each?

Question 9

The topsoil is roughly equivalent to which master horizon?

Answer 9

A Horizon

Question 10

While the topsoil is where the majority of plant roots are located, why is an understanding of the subsoil and its properties important for proper soil management?

Question 11

What are the four major components of the soil?

Answer 11

Minerals
Water
Air
Organic Material

Question 12

What is the difference between soil texture and soil structure?

Question 13

Why are soil pores important?

Question 14

What are some of the benefits of organic matter in the soil? What is humus?

Question 15

Why is water such an important component of the soil?

Question 16

What special properties of soil water distinguish it from other forms of water?

Question 17

What is pH, and why is it considered a “master variable” in the soil environment?

Question 18

Particularly in terms of plant nutrient availability, why is the interaction of the soil solution and soil solids so important?

Question 19

What are the three mechanisms by which plant roots acquire nutrients from the soil system?