Soil Science Lect 9

Soil is alive and probably

the most diverse ecosystem on earth, most microbial taxa >95% have yet to be identified

Bacteria

enormous diversity, decomposers, reproduce fast, spores/dormant survive in poor conditions

Archaea

extremophiles, survive at extremes pressure/temp/salinity, different components in cell membrane/wall

Fungi

1.5 million species estimated, diverse, filamentous→hyphae, one clone can be large, grow at low pH and water conditions

Symbiotic Relationships

both organisms involved benefit, N fixation, Mycorrhizae

Nitrogen Fixation

Symbiotic, inoculation with correct bacteria,infection of legume roots, nodulation, legume feeds bacteria, bacteria provides fixed nitrogen

Mycorrhizae

relationship between plant roots and mycorrhizal fungi, extends roots system, fungi gets food from plants,

What is Mycorrhizae especially important for?

P uptake

Functions of Soil Mircobes

capture energy convert co2 to OM, breakdown residues cycle nutrients, enhance plant growth