B6 - Life in soil Flashcards Preview

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Flashcards in B6 - Life in soil Deck (20):

What does soil contain?

- different sized particles
- living plants and animals
- decayed remains of dead plants and animals
- air
- water containing dissolved minerals


Why can plants grow in soil on Earth?

Because it provides:
- minerals needed for growth
- water to stay alive
- anchorage for roots


What are the three states of soil?

- acidic
- alkaline
- neutral


Why do sandy soils drain well?

Sandy soils drain well because they have large mineral particles with big air spaces.


Why do clay soils become waterlogged easily?

Clay soils become waterlogged easily because they have small particles that are close together.


Why is loam a good soil?

Loam is a good soil because it contains clay and sand and has large mounts of humus.


What is humus?

Humus is decomposed material.


Why do plants find it difficult to live in dry soils?

They need water for photosynthesis.


Why do plants find it difficult to live in waterlogged soils?

This is because they need oxygen for respiration.


What would be the pH of a neutral soil?

The pH would be 7.0


Describe the test for air.

Using a tin to collect a soil sample, find the mass of the soil and the tin and then fill it with water until the tin is completely full. Then find the mass of all three and find the difference in masses.


Describe the test for water content.

Weigh a sample of the soil and then slowly dry the soil in an oven. Then weigh the soil again. The loss in the mass is the mass of water in the soil.


Describe the test for humus.

Take a sample of dry soil, burn it with a bunsen burner and then weight it again. The loss in mass will be equivalent to the humus content.


What is aerating the soil?

Aerating is increasing the amount of air in soil.


What does a food web show?

A food web shows the feeding relationships of some animals and their predators.


What are decomposers?

Decomposers are organisms that break down dead plants and animals, releasing elements into the soil.


Name five things that live in the soil.

Herbivores, detritivores, carnivores, bacteria and fungi.


What are detritivores?

Detritivores feed on dead organic matter.


How do earthworms improve the structure of soil?

- burrowing, which aerates the soil and improves drainage
- eating and burrowing through the soil which mixes the layers in the soil
- adding chalk as it eats the soil, neutralizing acid soils


Explain the importance of earthworms to agriculture.

Earthworms naturally improve the structure and fertility of the soil, and without them the layers of soil would be thin and few plants would grow.