Terrestrial plants need soil to grow. Roots anchor plants in soil. Roots absorb nutrients like nitrates, nitrites, potassium and phosphorus from soil. The three layers of the soil profile are topsoil, subsoil and bedrock.
1. Topsoil – mostly made of _____________________________________________. There are also small inorganic particles and lots of _________________________ like worms, bacteria and fungus. Topsoil has the __________________ for plants.
2. Subsoil – a very compact layer made mostly of ____________________________________ particles.
3. Bedrock – this _____________________ means water cannot pass through.
When water reaches the bedrock _____________________ forms. A well must be dug so that the tube goes below the _______________________ or the _________________________ of the ground water.
Three types of topsoil
The types of topsoil are determined by the amount of humus and the amount of inorganic sand, clay and rock particles.
1. ____________ Soil – the best soil for ______________ has lots of ____________ and inorganic particles of different sizes for ___________________. Loam _______________________________ and dries out slowly.
2. Clay soil – the _______________ particles make root growth difficult and clay holds _________________.
3. Sandy soil – _________________ particles let water flow through quickly _________________________ and drying out ______________________.

Good loam soil surrounds roots with
__________________________________
_______________________ in different sized particles of sand and clay.
Human actions impact topsoil
The __________________ of trees and plants prevent soil from _______________
______________ with ________________ or rain water runoff.
_________________________ leads to huge losses of topsoil from ____________________________.
Farming also leads to soil degradation from use of pesticides that kill all the microorganisms, or
_____________________ that adds a little more salt every year.
If farmers apply ____________________________________________ or put fertilizer on the soil before it rains, the fertilizer runs into rivers and lakes causing ____________________________.
Steps of Eutrophication (Pearson p 78).
1. Nitrates and ________________________ in surface runoff _________________________.
2. Nutrients ______________________________________ on the surface.
3. Aquatic plants ___________________.
4. Sunlight is blocked and _____________________________________________________.
5. Decomposers feed on dead plants, _____________________________________________.
6. Animals __________________ from lack of oxygen.
7. Lake can only support surface aquatic plants.
Humans can _____________________ topsoil by protecting ______________. Good farming practices like
_______________________ and limited applications of pesticides can protect good quality topsoil.

Soil and Ecosystems
Topsoil apple demo https://www.youtube.com/watch?v=JBi21F9F6t0
Terrestrial plants need soil to grow. Roots anchor plants in soil. Roots absorb nutrients like nitrates, nitrites, potassium and phosphorus from soil.
The three layers of the soil profile are topsoil, subsoil and bedrock.
1. Topsoil – mostly made of decaying matter called humus. There are also small inorganic particles and lots of living organisms like worms, bacteria and fungus. Topsoil has the nutrients for plants.
2. Subsoil – a very compact layer made mostly of inorganic rock, sand and clay particles.
3. Bedrock – this solid rock means water cannot pass through.
When water reaches the bedrock ground water forms. A well must be dug so that the tube goes below the
water table or the top surface of the ground water.
Three types of topsoil
The types of topsoil are determined by the amount of humus and the amount of inorganic sand, clay and rock particles.
1. Loam Soil – the best soil for crops has lots of humus and inorganic particles of different sizes for air pockets. Loam holds water well and dries out slowly.
2. Clay soil – the tiny clay particles make root growth difficult and clay holds too much water.
3. Sandy soil – Large sand particles let water flow through quickly taking away nutrients and drying out too fast.
Good loam soil surrounds roots with humus, air, water and nutrients in different sized particles of sand and clay.
Human actions impact topsoil

The roots of trees and plants prevent soil from eroding with wind or rain water runoff. Deforestation leads to huge losses of topsoil from rainwater runoff. Farming also leads to soil degradation from use of pesticides that kill all the microorganisms, or irrigation that adds a little more salt every year.
If farmers apply excess fertilizer or put fertilizer on the soil before it rains, the fertilizer runs into rivers and lakes causing eutrophication.
Steps of Eutrophication (Pearson p 78).
1. Nitrates and phosphates in surface runoff enter lake.
2. Nutrients fertilize aquatic plants on the surface.
3. Aquatic plants grow.
4. Sunlight is blocked and plants below the surface die.
5. Decomposers feed on dead plants, using the dissolved oxygen.
6. Animals die from lack of oxygen.
7. Lake can only support surface aquatic plants.
Humans can protect topsoil by protecting forests. Good farming practices like crop rotation and limited applications of pesticides can protect good quality topsoil.