Plants, Nutrients and Australian Soils

Compounds such as sugars, proteins and cellulose are readily mineralised, liberating CO₂ and releasing mineral nutrients.

For example, the amino acid glycine breaks down to yield ammonium according to the following equation:

Lignin and other chemically resistant compounds are released only slowly but over time are incorporated into the mineral soil by the soil fauna.

Not all of the nutrients released through decomposition and mineralisation are immediately available for plant uptake. Some are immobilised by microbes, which require them for their own metabolism and growth.

In forests of south-eastern Australia, lyrebirds play an important role in incorporating decomposing litter into the soil. They forage by raking the litter layer with their powerful feet, disturbing and mixing large areas of the forest floor along the way. The unlucky worm also plays a part in buring organic matter deeper in the soil profile.