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Fact or fiction?
In article ,
The Cook wrote: On Tue, 13 Apr 2010 14:41:14 -0700, Billy wrote: In article , The Cook wrote: I seem to remember that wood as it decomposes uses up the nitrogen in the soil. Not really good for the garden. Old wives tale or true? In terms of both its physical and chemical properties, wood is an exceptionally difficult substrate to degrade. One of the principal reasons is that wood contains very low levels of nitrogen, which is needed to produce the enzymes that degrade the main structural polmers of wood - cellulose (about 40-50% of the dry weight of wood), hemicelluloses (25-40%) and lignin (20-35%). The lignin component also presents a barrier to wood decay because lignin is a complex aromatic polymer that encrusts the cell walls, preventing access of enzymes to the more easily degradable cellulose and hemicelluloses. In addition to these points, wood often contains potentially fungitoxic compounds, which are deposited in the heartwood. In broad-leaved trees the toxic compounds are usually tannins, well know for their ability to cross-link proteins, making animal skins resistant to decay. In contrast, conifers contain a range of phenolic compounds such as terpenes, stilbenes, flavonoids and tropolones. The most toxic of the tropolones are the thujaplicins which act as uncouplers of oxidative phosphorylation; they are particularly abundant in cedarwood, making this a naturally decay-resistant wood for high-quality garden furnishings, etc. http://www.biology.ed.ac.uk/research...iology/woodrot s.htm When the nitrogen is no longer needed for enzymes or fungal growth, it is released back into the soil environment for use by other microbes, and plants. Actually my husband and I were discussing the cedar chips versus grass clippings as mulch for the rhubarb. He is thinking that the cedar would be there for a long time. I am thinking that the chips cost money and would get moved into the other parts of the garden. Grass clippings a free and do provide some nutrients for the plants as well as helping to keep the weeds down. We do have about an acre of grass that needs to be mowed regularly. Cedar chips would be the opposite of grass clippings as a mulch. Are we talking mulch as a ground cover, or mulch as a nutrient? Cedar chips breakdown slowly, making them a good ground cover, but a poor nutrient. Grass clipping break down quickly, making them a quick nutrient source for soil microbes. ---- "wood often contains potentially fungitoxic compounds, which are deposited in the heartwood. In broad-leaved trees the toxic compounds are usually tannins, well know for their ability to cross-link proteins, making animal skins resistant to decay. In contrast, conifers contain a range of phenolic compounds such as terpenes, stilbenes, flavonoids and tropolones. The most toxic of the tropolones are the thujaplicins which act as uncouplers of oxidative phosphorylation; they are particularly abundant in cedarwood, making this a naturally decay-resistant wood for high-quality garden furnishings, etc." http://www.biology.ed.ac.uk/research...Biology/woodro ts.htm ---- Am I missing a piece of the puzzle? -- - Billy "Fascism should more properly be called corporatism because it is the merger of state and corporate power." - Benito Mussolini. http://www.youtube.com/watch?v=Arn3lF5XSUg http://www.thirdworldtraveler.com/Zinn/HZinn_page.html |
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