Zusammenfassung der Ressource
B6e Summary
- Contents of Soil
- complex mixture of
- different sized minerals/particles
- humus
- formed by decomposition of dead organic material
- water
- air
- supports diverse community
- of living organisms
- made of mineral particles
- between them are air spaces
- around them is a film of water
- Types of Soil
- sandy soil
- large mineral particles
- large air spaces
- clay soil
- small mineral particles
- much closer together
- loam
- mix of sand and clay
- large amount of humus
- Tests for...
- Water Content
- 1. weigh, dry in a warm area and reweigh
- 2. repeat until a constant mass is reached
- 3. the difference is the mass of water in the original sample
- (you can use this to work out a %)
- Humus Content
- 1. take a dried soil sample and weigh it
- 2. heat it strongly with a bunsen burner to burn the humus
- 3. the decrease in mass is equal to the amount of humus before
- Air Content
- 1. fill a can with soil and find the mass of the can with soil
- 2. slowly add water to soak through
the soil and fill air spaces
- 3. when water reaches top of can find the
new mass of the can, soil and water
- 4. find the difference between the 2 masses, this is the mass
of water added 1cm3 = 1g, which is also the amount of air
- Life in the Soil
- animals
- Herbivores
- feed on living plant matter
- e.g. slugs, snails
- Detrivores
- feed on dead organic matter
- e.g. earthworms, millipedes
- Farmers buy worms and add
them to soil to improve it, good
for soil structure & fertility
- Carnivores
- feed on herbivores & detrivores
- e.g. spiders, centipedes
- plants
- need soil for minerals, water and to anchor them
- EARTHWORMS
- aeration
- burrows create gaps
- increases 02 content in soil
- drainage
- burrows create gaps
- reduces flooding
- mixing
- eats soil and passes waste elsewhere
- nutrient distribution
- making soil finer
- release CaCO3 into gut
to help digestion of leaves
- easier for plants to grow
- fertilising it
- excretion
- neutralises soil acidity