Lesson Activities / Tasks

• Lesson Activities
• • Watch video - dialog below
  • Carry out own soil sample mixing as seen in video this can be done by teacher or ideally as whole class activity.
  • Allow sample time to settle - pupils could write out method of investigation while soil settles
  • Draw diagram of soil sample
  • Measure Layers of soil and produce a pie chart of results
  • Complete relevant section of pupil work book

  Plenary:

  • Do quiz for first section answers…

Video Dialog

• After the pooh is spread in fields the farmer mixes it in to the soil along with any remains of the previous crop often by ploughing
• This material - poo and previous crop plant material is called organic matter which simple means stuff that came from something that was once alive.
• What do you think then happens to this organic matter.
• To answer this you need to know a little bit about soil.
• What is soil made from? Does anything live in soil?
• Lets make mud pies to see what soil is made of.....
• No not the mud pies you made when you played out......
• But 'scientific' mud pies! Oops but not with best kitchen spoons!!!!
• Once the 'mud pie' has settled you get this - the bits or particles of soil have settled into different layers.
• The biggest or heaviest particles sink first so settle on the bottom of the pot.
• These are sand particles.
• The top layer is made up of the smallest particles
• The are clay particles
• The particles in between are called loam
• Then on the top or even still floating are very small pieces of organic matter - dead plant and animal material as we said.
• If we look at some of these soil particles under a microscope this is what we see.
• What does it remind you off?
• Do you think they look like stones or rocks?
• Well that is exactly what they are small pieces which have been broken of rocks by rain, wind, ice, plants growing on them, and lots of other ways.
• This is called erosion and just means breaking down.
• So now we have 1 ingredient of soil - broken or eroded rocks
• How much of the different size particles a soil contains decides what type of soil it is sandy, loamy or clay soil
• Settled on the top layer or floating in the water is the second ingredient of soil- organic matter
• So when he mixes poo with the soil in his fields the farmer is really helping to make more soil
• The organic matter is also broken down in small pieces by the animals, minibeasts and micro-organisms which live in the soil.
• Creatures such as earthworms, centipedes and woodlice.
• This type of breaking down is called decay and it happens to all living things when they die.
• When organic matter decays it releases food or nutrients into the soil which is important for plants - more later
• This process of erosion and decay is a very slow process and take thousands or even millions of years.
• So we must look after the soil we have got as it takes a very long time to make new soil.
• Don't think of soil as 'mud for pies' but more and ingredient of life on earth in which plants grow and animals live.
• So when farmers spread poo on their fields they are adding an important ingredient of 'new' soil and also nutrients.