Contain carbon. Plant - or animal-based.`

Organic matter from plant and animal debris starts to accumulate and has both physical and chemical effects on the soil. Over time, bulky organic matter gradually decays and becomes Humus. This colloidal state acts as glue in the soil as well as holding on to plant nutrients.

About 5% of soil content generally (80% hummus, 10%roots, 10% organisms)

Contain carbon Plant - or animal-based Living Organic Matter: Worms/bacteria/fungi/nematodes/moles/plant roots. • Byproduct of living animals or end product of death / decomposition: Dead Organic Matter: Worms/bacteria/fungi/nematodes/moles/plant roots, plus plant remains (natural or added as compost)

Animal by-products (manure/bones/hooves/blood).

*Farmyard manure 😘 • becomes Humus. • physical and chemical effects on the soil • generally acidifying.

Garden compost: • can be richer in plant foods; • unpredictable nutrient content.

Leaf mould • good physical effect on soil structure • limited foods value • time to produce

Quick Breakdown Mulches • Well rotted or coarse compost, strawy manure • breaks down to become Humus over a season • has other benefits eg reduce weeds, retain moisture as with slow breakdown mulches

Slow breakdown mulches: • Un- or incompletely- composted materials eg Bark, wood shaving, shredded paper • Breaks down over several seasons but used mostly for weed control and prevention of soil capping • Uses nitrogen as it breaks down which may affect fertility of soil for surrounding plants.

Humus: • Remains of bulky organic matter in the soil after decompostion • holds plant foods and water • creates soil structure