11 February 2007
Ammonia: a candidate for nitrogen transfer
In mycorrhizal associations, the fungal partner assists its plant host with nitrogen and phosphorus uptake while obtaining photosynthetically fixed carbon. Recent studies in mycorrhiza have highlighted the potential for direct transfer of ammonia from fungal to plant cells. This presents a new perspective on nitrogen transfer at the mycorrhizal interface, which is discussed here in light of recent progress made in characterizing a large array of membrane proteins that could fulfil the function of transporting ammonia.
03 January 2007
transect points: Black Earth
Peak Energy has a long post on Terra Preta that brings together what has been established on the subject. As of yet, there is no direct mention of the role of glomalin, just a minor mention of the mutualistic fungi that produce it. Glomalin is an unvalidated factor in Terra Preta formation that several of us sense will be demonstrated by soil research as fundamentally important.
Spurred on by back40, I am fascinated with bio-char, Terra Preta's key soil amendment. Last summer I constructed a small charcoal retort out of a cracker tin. I used it to produce small pilot batches of low temperature charcoal. Hoping to transform my simple charcoal into a reasonably bio-char-like material, I am currently composting my bits.
16 December 2006
transect points: Invasive Earthworms
Research shows that invasive earthworms are damaging forest soils and are a menace to species diversity. The problem is most often associated with formerly glaciated regions, where native populations of earthworms are not present. Comparing soil in front of the invaders to post invasion conditions demonstrates that these worms cause soil compaction, reduced soil fertility, and increased erosion. It appears that these invaders are capable of alterations deep enough into the soil profile to result in a change in soil taxonomic classification at the order level. Other concerns are damage to rhizosphere functions, impairing soil carbon sequestration capacity.
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