Chapter 10
Mineral Nutrition and Transport in Plants
CHAPTER OUTLINE
Soil
Soil is composed of inorganic minerals, organic matter, air, and water
A soil’s organic matter consists of the wastes and remains of soil organisms
About 50 percent of soil volume is composed of pore spaces
Soil organisms form a complex community
Soil pH affects soil characteristics and plant growth
Soil provides most of the minerals found in plants
Plants and People: Managing Your Lawn and Garden at Home
Plants and the Environment: Soil Salinization
Plants and People: Commercial Hydroponics
CHAPTER OBJECTIVES
1. List the four components of soil and give the ecological significance of each.
2. Describe the factors involved in soil formation.
LECTURE OUTLINE
I. What are the functions of soil?
II. What are the four components of soil?
A. What contributions do inorganic mineral particles make to soil?
1. What is soil texture?
2. How are sand, silt, and clay different?
3. How do soil particles effect the ability of soil to hold water and ions?
B. What are the sources of organic matter?
1. How does organic matter effect the ability of soil to hold water and ions?
2. What is humus?
C. How much of the soil volume is occupied by pore space?
III. How does soil pH affect mineral solubility?
A. What effect does pH have on leaching?
B. What is the optimum soil pH range for most plants?
C. How does acid precipitation influence forest decline?
IV. How did biologists determine which nineteen elements are essential for plant growth?
A. Why are some elements called macronutrients and others called micronutrients?
B. What are the ten macronutrients? What are their functions in plants?
2. Distinguish between organic and inorganic fertilizers and give examples.
a. What are the pros and cons of using each type of fertilizer?
b. What environmental hazards are associated with using manufactured
fertilizers?
V. How are water and dissolved minerals transported from the soil to the tops of plants?
A. What tissues and cell types are involved?
B. Describe the route taken by water and minerals as they flow from soil water to
the leaf.
C. How does the tension-cohesion theory explain the upward movement of water?
1. Where is the tension generated?
2. How is the tension generated?
D. What is the mechanism involved in root pressure as a means of water transport?
1. When does root pressure occur?
2. Can root pressure account for water movement in the tallest trees?
E. What is the mechanism involved in the uptake of dissolved mineral ions, particularly
in crossing plasma membranes?
VI. How are sugars translocated in plants?
A. What tissues and cell types are involved?
B. In what direction does the fluid in phloem move?
C. How does the pressure-flow hypothesis explain the movement of sugar in
phloem?
1. What is a sources and what happens at a source?
KEY TERMS
acid precipitation, p. 206
active transport, p. 215
adhesion, p. 212
illuviation, p. 203
inorganic fertilizer, p. 209
leaching, p. 203
root pressure, p. 213
sand, p. 201
silt, p. 201
TEACHING TIPS
1. Make abundant use of visual aids to help students understand the concepts in this
2. Provide a mnemonic to help students remember the nineteen essential elements. A
popular mnemonic used in the past has been: “C HOPKNS Ca Fe Mg Mo B Cu Mn Zn
3. Try having the students generate the lists of soil weathering processes, soil
components, and types of soil organisms. They usually already have this information but
4. Bring in a pint glass jar with about 5 cm of good loamy soil in it. At the beginning
of lecture, add water to twice the height of the soil, shake thoroughly, and casually set
the jar on the front table. During the hour, all the sand and most of the silt will settle
5. Have students debate the pros and cons of inorganic vs. organic fertilizers.