Date: Sun, 3 Jun 2001 21:27:40 -0400 Reply-To: Sustainable Agriculture Network Discussion Group Sender: Sustainable Agriculture Network Discussion Group From: Frank Teuton Subject: Re: John Jeavons and Regenerative Farming Content-Type: text/plain; charset="iso-8859-1" Greg wrote: > John Jeavons (JJ) uses carbon to nitrogen ratios of 15/1, 30/1, and 60/1. > This is generally not enough nitrogen to allow the compost to heat up very > much. Much of the digestion occurs thru mycorrhizal actions. He says the > cold composting methods burn off much less carbon than a hot(a pile with a > 5/1, C/N ratio) compost pile. The mycorrhizal actions also produce a myriad > of enzymes and antibiotics useful in plant propagation. The pile is turned > less frequently than a hot pile would be. > > I would suppose that this cold compost method emulates natural > decomposition that occurs on the soil surface. > > Thanks, > Greg With all due respect, Greg, this information is not correct. No one on the planet composts with a 5 to 1 carbon to nitrogen ratio, and 15 to 1 is very high nitrogen, eh? Perfect ratios for composting range from 25 to 1 up to 35 or 40 to 1, and this is not what determines heating, in any case. Heating occurs when microbial activity in combination with the insulation characteristics of the pile structure combine to cause heat buildup (heat is generated by metabolic activity, and insulation holds it in). It is quite possible to have hot piles comprised only of fall leaves if they are freshly fallen, as available carbon is high and nitrogen supplies are adequate, and it is also quite possible to have hot piles with only fresh wood chips; again, the overall C to N ratio is less important than available carbon and size and insulating character of the pile. A 30 to 1 C/N ratio may well end up conserving organic matter compared to a higher C/N ratio, according to some of the experts I have read; composting in the lower temperature ranges is beneficial for a number of reasons, but hot composting has great value for its rapid destruction of pathogens and weed seeds where necessary or desirable, most always followed by a cooler composting phase. Mycorrhizal fungi are not always present in compost, and are certainly not doing most of the work in composting, although other fungi are quite active. Hot composting and vermicomposting both end up with mycorrhizal fungi being consumed or inactivated; some kinds of mycorrhizal fungi absolutely need plant roots in order to live and multiply, and obviously this is not the environment in most composting situations, eh? see http://www.soilfoodweb.com/systems/compost/compost2.html#mycorrhizal I have a great deal of respect for John Jeavons and the work he has done, and in fact he points out other systems that he believes are part of the big picture, see http://www.growbiointensive.org/biointensive/InContext.html Composting techniques are flexible and offer different options to the grower depending on the needs of the feedstocks and plants being grown; but we need to understand correctly how the process works. Cold or cooler composting has some important virtues, including the preservation of higher biodiversity along with disease suppressive abilities. But until plant roots are present, even potentially mycorrhizal fungi aren't doing anything mycorrhizal, since there are no plant roots to dance with in the compost pile, eh? Myco-rrhizal= fungus-root....... Now compost added to soil may encourage mycorrhizal fungi already present to increase their activity, and you can inoculate soil that is deficient in mycorrhizal fungi in addition to adding compost or compost derivatives such as teas, but compost alone, even cold compost, is not an inoculant of mycorrhizae that is reliable, as I understand it, and the C/N ratios you describe above are way off base. Perhaps you need to double check your notes on that, eh? Good composting, Frank Teuton