Decay

• Conditions required for decomposition (decay)


  • Temperature
  • Amount of water
  • Amount of oxygen
• Decomposition takes place faster at warmer temperatures


  Enzymes used by decomposers work faster in warm conditions
• Compost heaps tend to be quite warm


  Decomposers release energy when they carry out aerobic respiration
• It's important that the compost does not get too hot, as this can denature the enzymes and kill the decomposers
• Decomposing microorganisms work faster if the compost is moist


  Many of the chemical reactions in decay require water
• It's important that gardeners do not allow a compost heap to dry out
• Decomposers carry out aerobic respiration

  This requires a good supply of oxygen
• The compost bin has holes in the walls to allow oxygen to enter, and gardeners mix the compost regularly to increase oxygen supply
• Anaerobic decay


  Decomposition that occurs in the absence of oxygen, producing a mixture of gases including methane (biogas)
• Small-scale biogas generators use plant materials or animal manure to produce biogas under anaerobic conditions