From bluestem@webserf.net Wed Nov 24 14:16:05 1999 Date: Wed, 24 Nov 1999 17:14:23 From: Bluestem Associates To: "sanet-mg@ces.ncsu.edu" Subject: Re: Do wood ashes increase nitrogen fixation? On Wed, 24 Nov 1999 11:13:23 -0500 (EST), Lawrence F. London, Jr. wrote: > >Dan Hemenway wrote: > >"Wood ash contains valuable trace minerals and I use it under inoculated >legumes to feed the rhizobia that fix nitrogen in the roots of the legume >crop. You will get a huge increase in N fixation if you do this." > >Is this true? Would you get the same effects with rock powders, compost >and seaweed or is there something special about wood ashes that make >rhizobia fix more nitrogen? Partially true. The major mineral co-factor in rhizobial nitrogen fixation is molybdenum. Vanadium is also tangentially involved. Most wood does not contain a lot of moly --- eucalyptus being a notable exception. The best rock powder source (by far) is phosphate rock, particularly some of the phosphates from the southeastern US. You can also purchase (at a very reasonable price) sodium molybdate inoculants (Urbana in St. Joseph, Missouri is one source) to mix with the rhizobia at seed planting. Properly used, molybdenum will release more energy, kilo for kilo, than uranium (increased N-fixation, leading to increased yields, leading to increased capture of solar energy). Best bargain in agriculture, and almost nobody uses it. Bart To Unsubscribe: Email majordomo@ces.ncsu.edu with the command "unsubscribe sanet-mg". If you receive the digest format, use the command "unsubscribe sanet-mg-digest". To Subscribe to Digest: Email majordomo@ces.ncsu.edu with the command "subscribe sanet-mg-digest". All messages to sanet-mg are archived at: http://www.sare.org/san/htdocs/hypermail