Our Living SoilMr Boland

Geography

What is soil?

Soil is the top layer of the earths surface.

It provides nutrient for plant growth and is the most important natural resource

Soil an essential natural resource is composed of....Can You guess the importance of each element?

Mineral particles 45% are remains of rock broken down, these are soluble as they dissolve in water.

Air 25% supplies oxygen and nitrogen to micro organisms.

Water 25% dissolves and distributes mineral nutrients to plants.

Micro-Organisms 5% break up the soil and eat plant litter making humus and the soil fertile.

Fill in the Blanks

Mineral particles ______% are remains of _______ broken down, these are soluble as they _________ in water. Feed plants

Air ______% supplies oxygen and nitrogen to ______________.

Water _____% dissolves and _________ mineral nutrients to _____.

Micro-Organisms ______% _______ up the soil and eat plant litter making _________ and the soil fertile.

Mineral particles 45% are remains of rock broken down, these are soluble as they dissolve in water.

Air 25% supplies oxygen and nitrogen to micro organisms.

Water 25% dissolves and distributes mineral nutrients to plants.

Micro-Organisms 5% break up the soil and eat plant litter making humus and the soil fertile.

What are the

percentages ?????

Soil creation

Weathering (Physical and chemical) and erosion breaks rocks down into loose material.

The climate in the area makes a distinct natural vegetation.

Both the remains of this vegetation and loose material mixes and forms soil.

Climate

Natural Vegetation

Provides dead Plants

Forms Mineral Particles

Erodes Parent Rock

Mixes to form soil

Climate: causes weathering and erosion to break down rocks into smaller particles.It is also responsible for the natural vegetation

Vegetation helps form humus when it dies.

Soil

WHAT DO THESE FOUR PICTURES SHOW?????

humus

How is Humus Made

Dead vegetation like leaves and grass are broken down by micro- organism, bacteria and fungi.

It forms a black coloured jelly substance called humus.

Oxygen is also needed to break down dead material.

Humus is very fertile and feeds more plants.

Nutrient cycle

Soil Profiles

A soil profile is a cross section of soil showing the different layers (Horizons)

Horizon A: The topsoil. This can contain humus and is usually darker in colour.

Horizon B: The subsoil. This contains less humus, is lighter in colour and has more stones.

Horizon C: The parent rock/ bedrock.

Soil creation

Weathering and erosion breaks rocks down into loose material. This mixed with climate, vegetation and human activity to produce soil.

Leaching and Hard Pan

Water percolates (soaks) through the soil. This is necessary to bring nutrient to plant roots.

Leaching occurs when rain washes minerals down from the A horizon to the B horizon. This makes soil less fertile.

In areas of heavy rainfall minerals gather and form a hard pan

The hard pan is impermeable, this does not allow water to pass through it.

Areas that undergo leaching are often wet, soggy soil.

Ex Monaghan

Types of soil

The formation of humus and the movement of water through soils help create different soil types.

Three soils that we are looking at are browns soils, podzols and tropical red soils

Brown SoilsDevelop in deciduous forests and are rich in humus.

-Occur in areas of moderate rainfall (800mm)and there is no leaching or no hard pans.

-Very Fertile- Arable (tillage) and pastarol Farming

-Found in Laois

Describe characteristics of the soil associated with these pictures

Podzols-Occur in coniferous forests with little humus.

-Occur in areas of resulting with high rainfall heavy leaching and hardpans.

-Grey colour due to little humus

-Infertile- suitable for grazing and coniferous forests.

-Found in high/wet areas like Cork and Tyrone.

Podzol Profile

Which soil is which? Explain your answer?

Name a county for each soil type???

Why is the soil on the

equator red???

Tropical Red Soils

Red soils are found on the equator.

Heavy plant litter is acidic which breaks rock down.

Rocks undergo chemical weathering due to heavy rainfall and high temperatures

The soil undergoes oxidation (rusting) to give it a red colour because there is a large amount of iron oxide in the rocks.

Though fertile if the forests are cleared heavy leaching makes the soil infertile

Exam Questions