Brown earth soils❤️

Question 1

Introduction to brown earth soils

Answer 1

• zonal soils, in response to climate
• developed because of deciduous forest eg. Oak and ash. Cool temp oceanic (5-17 degrees and 1500 mm rain)
• ideal=45%mineral matter , 25% air and 5%organic material

Question 2

How does the texture of brown earth soils develop?

Answer 2

• affected by weathering that occurs, because the type of mineral matter gives the soil its texture.
• in cool temperate climates freeze thaw action occurs in uplands and sheltered lowlands. Produces large angular sand sized mineral grains.
• chemical weathering releases nutrients and clay minerals into soil
• hydrolysis of granite rocks in temperate climates provides clay particles.

Question 3

What is the texture of brown earth soils in Ireland? Why does it have this texture?

Answer 3

• loam texture ( equal amounts of sand silt and clay) because the soil develops on various parent Rock eg limestone slate and sandstone
• developed on glacial till deposited at the end of the last ice age

Question 4

What is the humus content of brown earth soils? How does it develop?

Answer 4

• high
• humification (explain)
• rain washes the humus into the soil

Question 5

What is the humus content of brown soils in Ireland and why is it like this?

Answer 5

• the climate is mild so living things have an active period of nine months; they mix the humus and soil together and the bacteria and fungi make the humus
• autumnal leaf fall increases amount of dead organic matter

Question 6

What influences the PH of soils?

Answer 6

• parent material. Acidic soils form on acidic rocks eg sandstone. Alkaline soils form on lime rich rock eg limestone
• rainfall can mildly leach soil
• rain can mix with humus and create a weak humid acid
• presence of living things. Their droppings and decomposition after death can influence the ph
• acidic soils develop in upland areas with acidic crystalline parent rock, there is also increased rainfall in upland areas
• podzolisation. This is leaching by acidic water and this leads to pale soils. Occur in lowland eg midlands of Ireland

Question 7

What influences the colour of brown earth soils?

Answer 7

-Animals burrowing. mixes the soil and humus which makes the horizons virtually the same.
- humus content
Parent material. Sandstone= pale, limestone= dark