Soils

• Mineral particles 


  Sand, silt and clay, make up most of soil (45%)
• Permeability 


  The ability of water to flow through the soil
• Water 


  Binds soil together, dissolves minerals and nutrients so plants can soak them up through roots
• Air 


  Found in pores of soil, provides necessary oxygen and nitrogen to soil
• Organic matter and humus

  Made of organisms/microorganisms in soil - worms move through and circulate soil and plants decay into humus
• How soil is formed

  Climate, human activity and time

  
• Soil profile 


  Vertical section of soil from it‘s surface downwards
• What are the soils’ layers called

  Horizons
• A Horizon 


  Known as topsoil, very fertile, dark colour due to lots of humus and plant litter
• B Horizon 


  Known as subsoil, lighter colour due to less humus, contains more stones
• C Horizon 


  Knows as bedrock, has a solid rock base with smaller rock pieces on top
• Leaching 


  Occurs after large amounts of rainfall when water percolates through soil washing nutrients and minerals towards B horizon, depriving plants of minerals and nutrients and creating a hard pan from minerals between A and B
• Breakdown of plant litter

  Plant litter breaks down to humus (humification), oxygen is then required to assist breakdown of plant litter, to keep organisms alive
• Brown Soil 


  Most common soil in Ireland, found in areas of limited rainfall such as midlands and deciduous forests, fertile and good for farming
• Podzol Soil


  Found in highland, coniferous areas with more rainfall, grey in colour, has little plant little to be turned to humus and is less fertile
• Gley Soil


  Found on rolling low land or gently sloping hills, blue-grey in colour, thin-floods-becomes waterlogged, nor fertile
• Peaty Soil


  Known as bog land, takes thousands of years to form, dark in colour and becomes heavily waterlogged, not fertile