Factors Affecting Plant Growth

16.1

Soil– Broken rock (erosion, etc)– Humus

• Decomposing organic matter.– acts to bind mineral particles together and retain water and atmospheric

gases.– Provides some nutrients for plants.

– Living organisms• Plants, ,animals, fungi, and micro-organisms. • The total mass of organisms living in the soil is much greater than

the sum of mass of all organisms above ground.– Air

• Network of spaces created by roots and movement of animals such as earthworms.

– water

Factors affecting Growth

• Growth regulators – ie. gibberellin, auxin, etc.• Nutrients• Sunlight• Water• acidity

1) Nutrients

• Essential nutrient: materials that a living thing needs to make its own structures and obtain energy for survival.– Organism can not make them themselves. Ex/

humans need to injest vitamin C and glucose. Plants can make these, so they are not ‘essential’ for them.

• Essential Nutrients of Plants:– Carbon dioxide• Land plants acquire

from air.• Water plants from

soil.– Water• From soil.

– 6 soil elements

• Thinking Lab, Page 585– #1 - #6.

2) Sunlight

• Equation for Photosynthesis:

• What would happen to the production of glucose if there was limited sunlight?

• How would limited glucose levels affect a plant’s growth?

3) Water

• What affect(s) would insufficient water supply have on a plant? Why?

• Read the ‘Pause/Record’ on page 588. What do you think?

Section Expectations

• Understand the role of each of the following in terms of plant growth and survival– Essential minerals/soil– Animals in soil– Water– Carbon dioxide

• Understand the four nutrient cycles.

Homework

Page 591, #2, 4, 5, 6