Bacterial vs Fungal • Grass – usually bacterially dominated soil • Forest – fungally dominated • Ideal orchard soil = fungal dominance 10 x higher than bacteria – a ratio that defines forest-edge ecology Shifting the ratio • Bacteria utilize simple organic compounds like root secretions and fresh plant residue • Fungi respond best to surface decomposition while bacteria prefer soil disturbance. • Fungi use more complex compounds like cellulose, lignins and soil humus. • Bulky organic material as mulch –build soil from top down as does nature Amazing Mycorrhizae! •Symbiotic relationship with roots •Over 90% of plants form relationship •Absorptive area of roots massively increased •Nutrients can be transported up to 40m •C-rich sugars traded with nutrients and water •Produce glomalin (gives soil it’s tilth), growth factors and anti-biotics •Can even protect root from pests •Trees linked to other trees & plants Mycorrizal fungus on root Mycorriza on root hair Root-eating nematode captured by fungal hyphae!!!