From bluestem@webserf.net Thu May 20 09:24:17 1999 Date: Thu, 20 May 1999 10:07:18 +0100 From: Bluestem Associates To: "sanet-mg@ces.ncsu.edu" Subject: Nitrogen in organic agriculture I should think if any group would understand that use patterns and results would be all over the map, it would be *this* one. That said, a few observations. Many (perhaps most) of the organic farms that I inspect do *not* capture enough nitrogen to maintain a productive system over the long term. In that respect Avery and some of the other naysayers have a valid *empirical* point. These farms, however, are almost always short of nitrogen owing to poor nitrogen management (insufficient N fixation, manure management problems, etc.). It is entirely possible for a well-managed organic farm to capture all the nitrogen needed for "high-yield" production. In fact, it is not at all uncommon for an organic system to become too *rich* in nitrogen one or two rotation cycles after the transition, at which point the grower shifts to mixed hay (rather than straight legumes) and things settle down. Virtually all farmers (organic and otherwise) neglect the valuable role played by molybdenum in improving the efficiency of nitrogen capture. With well-considered additions of molybdenum, it is quite possible to capture more solar energy (through increased yields) than can be released from an equal weight of uranium via nuclear power. A few grams per hectare is usually all that it takes, added with inoculant at seeding. This because the nitrogenase component of the rhizobial nitrogen fixation reaction is dependent on an Fe-Mo protein, with moly being the limiting factor. Editorial comment about Chilean nitrate --- if organic is to allow any soluble nitrogen at all, it should be in the form of ammonium sulfate, not as a nitrate. Every other nutrient sulfate is already permitted, and AS is much better for soil microbes than the nitrates. Also, any idea that an organic inspector can determine the difference between 10-20 kg/ha nitrate and 50-60 kg/ha or even more (split apps) is ... pure fantasy. I have to chuckle when the naysayers criticise organic production as "inefficient" when their Farm Bureau buddies routinely knife in 400 units of anhydrous per acre every autumn and then have to come back over their corn with liquid 28 the following season just to make sure they have "enough." Conventional American agriculture is "efficient" (I suppose) in the same way as the American consumer economy. You can jump into a 2-ton SUV and drive it three blocks to pick up a 2-ounce packet of razor blades, and marvel at the "efficiency" of it all--- and look down one's nose at the scruffy unshaven neighbours -- but it is tragically laughable to conclude from that situation that walking and bicycles are inadequate. Bart Hall Lawrence, Kansas 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