Q&A

DEAR NEW FARM:
I am a Ph.D. student at the University of Florida and am taking a class on world agriculture. The instructor is very dogmatic about the use of synthetic nitrogen. I would appreciate any information you might have as well as other sources you can lead me to that I can use in this class to provide the other side of the argument.

Thank you,
Brad Walker

DEAR BRAD:
You are probably aware that UF just cut the ribbon on the first dedicated organic research department of any land grant university in the U.S: www.napa.ufl.edu/digest/stories/organic0301.html. Someone over there might offer you some good cannon fodder, or even better, help you to build a bridge between the mainstream agriculture department and the folks who have got it right!

We get frustrated ourselves when we hear reporters repeat as statement of fact that synthetic nitrogen is necessary to feed a burgeoning population (NPR, no less) every time they do a peice on Fritz Haber or some other related historical figure connected to the synthesis of nitrogen.

We believe that the poor farm management practices so ubiquitous across the American landscape are largely due to who has traditionally funded land grant universities: the companies that make pesticides and herbicides, synthetic fertilizers, and are now pushing transgenic crops.

The late Donella Meadows wrote an excellent piece for the September/October 2000 issue of Organic Gardening magazine entitled Our Food, Our Future which lies bare the myth of synthetic inputs and GMOs as the only hope for feeding a burgeoning world population. After derailing this notion, Meadows explains why, and how, organic agriculture can do the job just fine.

The Rodale Institute’s Farming Systems Trial® and Compost Utilization Trial have produced a number of peer-reviewed research papers that demonstrate how nitrogen is more efficiently utilized in an organic system. Among these findings, says research agronomist Dave Wilson, are the facts that:

• Synthetic fertilizers make nitrogen available to crops very quickly. This makes them more prone to leaching, which can pollute surrounding land and water—think dead zones in the Chesepeak Bay and Gulf of Mexico. Organic nitrogen sources are released slowly throughout the growing season and contribute to N reserves in the soil. Organic amendments can also improve soil structure and stimulate soil biological processes, particularly in degraded soils.
• Synthetic nitrogen fertilizers speed up the decay process of organic matter so that it is released in the atmosphere as carbon dioxide, a major greenhouse gas. In an organic system, carbon is stored in soil and plant tissue and is recycled.
• Leguminous cover crops, an integral part of an organic system, fix nitrogen from the earth’s atmosphere and accumulate soil carbohydrates through plant biomass. These “green manures” also improve soil structure and help prevent erosion. They go to work deep in the soil, fostering symbiotic relationships between soil microbes and living roots; beneficial products of these relationships include mycorrhizal fungi, which bolster a plant’s ability to take up nutrients and water, and glomalin, a glue-like substance that binds soil particles together and a contributes to tilth and stability.

For more on the subject, you can purchase the publication The Rodale Institute Farming Systems Trial™ in our bookstore. Some of the Institute’s peer reviewed articles on this subject include:

1. Hu, S., Grunwald, N., Van Bruggen, A., Gamble, G., Drinkwater, L., Shennan, C., and M. Dement. 1997. Short term effects of cover crop incorporation on soil carbon pools and nitrogen availability. Soil Science Society of America Journal 61(3):901-911.
2. Pallant, E., Lansky, D., Rio, J., Jacobs, L., Schuler, G., and W. Whimpenny. 1997. Growth of corn roots under low-input and conventional farming systems. American Journal of Alternative Agriculture 12(4):173-177.
3. Drinkwater, L.E., Wagoner, P. and M. Sarrantonio. 1998. Legume-based cropping systems have reduced carbon and nitrogen losses. Nature 396: 262-265.
4. Douds, D., and P. Millner. 1999. Biodiversity of Arbuscular Mycorrhizal fungi in Agroecosystems. Agriculture, Ecosystems and Environment 74:77-93.
5. Drinkwater, L., Janke, R., and L. Rossoni-Longnecker. 2000. Effect of tillage and intensity on nitrogen dynamics and productivity in legume based grain systems. Plant and Soil 227(2):99-113.

NF

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