Sub 3: Decomposition

Question 1

what is humus and litter?

Answer 1

humus is completely decomposed organic matter and improves fertility of soil
litter is undecomposed organic material

Question 2

what factors affect decomposition?

Answer 2

type of detritus
type and abundance of decomposer/detritivore
environmental conditions - temperature, moisture, aeration, nutrient availability

Question 3

what are compost accelerators?

Answer 3

increase the rate of decomposition by providing a source of nitrogen. examples -
artificial - nitrogen with bacteria and enzymes
natural - grass, nettles, comfrey and chamomile

Question 4

what is decomposition ?

Answer 4

it is the breakdown of organic material into inorganic material by microorganisms

Question 5

what are the two types of organism involved in decomposition?

Answer 5

detritivores and decomposers

Question 6

what are detritivores?

Answer 6

are soil invertebrates that ingest organic matter internally using enzymes and excrete it back into the soil in a form that can be further decomposed or used by plants.

Question 7

how do detritivores increase the rate of decomposition?

Answer 7

they reduce the particle size of the detritus increasing its surface area making it easier for decomposers to break it down

Question 8

what are decomposers?

Answer 8

organisms such as bacteria and fungi which absorb organic nutrients from dead organisms and waste from living organisms, converting them into inorganic molecules by secreting digestive enzymes and absorbing the products of digestion - external digestion

Question 9

what is another name for decomposition?

Answer 9

mineralisation