From lflondon@mindspring.com Wed Feb 23 14:51:30 2000 Date: Wed, 23 Feb 2000 14:42:11 -0500 From: "Lawrence F. London, Jr." To: lflondon@mindspring.com, london@metalab.unc.edu Subject: (fwd) Re: Ethylene cycles On Tue, 22 Feb 2000 23:52:12 -0500, in permaculture Keith Johnson wrote: To quote from an article on Soil Fertility, by Lea Harrison, in the Permaculture Activist (#26, May 92): "Micro-organisms are extremely numerous in healthy soil; eg. one gram of healthy topsoil contains about 1,000 million bacteria. All the micro-organisms that break down organic matter, are aerobic organisms. That is, they can only function in the presence of oxygen. All plant pathogens, which cause plant diseases, are also aerobic organisms. Even in well aerated soils, aerobic organisms use up oxygen faster than it diffuses into the soil. This creates, at any tiime, many microsites without oxygen, all through the soil. Anaerobic bacteria, which function in the absence of oxygen, grow and multiply at these reduced microsites. They produce ethylene, which inactivates, but doesn't kill, aerobic micro-organisms. There is a complex rocking backwards and forwards between the functioning of aerobic and anerobic bacteria, all the time, at microsites scattered all through the soil." In brief, the ethylene is the cycling back and forth in soils between aerobic and anaerobic conditions. Under both conditions nutrients are rendered available which would not otherwise be so. Both parts are essential for healthy balanced soil. Keith Johnson "Lawrence F. London, Jr." wrote: > Still interested in a definition of ethylene cycles. > > Lawrence F. London, Jr. Venaura Farm intergarden.com InterGarden metalab.unc.edu/intergarden InterGarden metalab.unc.edu/permaculture PermaSphere metalab.unc.edu/intergarden/orgfarm AGINFO lflondon@mindspring.com london@metalab.unc.edu