Wednesday, June 02, 2010

Adaptive Nitrogen Management

Harold M. van Es, Cornell University Department of Crop and Soil Sciences, Soil Health

Dr. van Es introduced his team's effort at a comprehensive, quick, and cheap soil test that goes beyond the standard chemical measurements to include physical and biological properties as well. I would like to see a paper showing how much variation in yield (b/c that is the output variable of interest to farmers) this test can account for, compared to other more comprehensive tests or even expert in-field evaluation.

Dr. van Es than discussed his work creating an adaptive nitrogen management tool that would completely bypass soil tests. His on-line tool uses rainfall patterns to estimate loss of nitrogen from corn fields and than recommends how much "booster" N to add. The benefits include less overall use of N. Interestingly, the loss of N in wet weather is exacerbated in soils with high organic carbon because of increased decomposition rates, according to Dr. van Es. Unfortunately, he did not discuss the dynamics of N under alternative farming (no synthetic fertilizer, no-till with cover crops, etc) practices that could obviate the need to even add N. I realized that one thing that's nice about monoculture corn across most of the mid-West is that the standardization makes it easier for science research to be relevant to a lot of people. It would be harder for Dr. van Es to research all the different alternative management techniques and apply recommendations for adaptive management to each.

The reason for internet-based adaptive management is a lack of real-time on-the-ground data on, say, soil moisture levels, N content, etc. But this is changing and Dr. van Es did show a few slides about what may be the future, with combines and irrigation equipment festooned with hi-tech spectrometers to gauge how much N plants have. The technique has been shown to be successful with wheat, but is still being developed on other crops.

Some links:

Sustainable Agriculture Research and Education

Alternative Farming Systems Information Center

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