soils

• Soil helps vegetation retain water, fertile soils also have nutrients, deep soils support vegetation with their long roots. And if a soil is acidic it can’t support as much vegetation due to lack of lime
• Vegetation influences soil as it provides plant litter to form humus, reduces the effects of leaching and slows down or prevents soil erosion as roots bring soil together
• Soil is the layer of loose material of the earths surface
• Soil is made up of water, air, living organisms, humus and mineral matter
• Air fills up space between soil particles
• Living organisms in soil help create humus
• Humus is decaying organic matter and it provides nutrients
• Water contains dissolved minerals for soil
• Three layers of soil: topsoil, subsoil and parent rock
• Topsoil is dark in colour as it has a high humus content and most organisms live in topsoil
• Subsoil is lighter in colour and has more stones
• Leaching: heavy rainfall washes minerals, nutrients and humus down into horizon B(subsoil). meaning horizon A (topsoil) loses fertility as roots cannot reach nutrients in horizon B. With sever leaching, minerals can gather up at bottom of horizon A where they are cemented together to make a hard crust/pan.
• 4 main types in Ireland are brown, podzol, pleaty and gley
• Brown soil: in areas with deciduous forest (provides huge amounts of plant litter), rain fall limited meaning no leaching, very fertile and suitable for farming, found in drier lowlands
• Tropical red soils found in tropical climate regions with hot wet climates, chemical weathering decomposes bedrock quickly, normally fertile but can become leached
• Podzol soil: formed in areas with coniferous trees, greater rainfall causing leaching, hard pan may develop, infertile and slightly acidic, found in wetter uplands in Cork, Galway and Wexford