Hypoxia

Today I attended a Soil and Water Management Seminar put on by Extension Service.  Overall it was a well doe program focusing on using biomass for fuels.  However there were other topics of interest as well. 

Dennis McKenna of the Illinois Department of Agriculture put together some interesting information about hypoxia.  the hypoxia zone varies from year to year, but it is always there.  The zone consists of areas in the Gulf of Mexico with less than 2 ppm of oxygen.  The low oxygen is caused by algae blooms that are fueled by nitrogen and phosphorous in deposited in the Gulf out of the Mississippi watershed.  The Hypoxia Advisory Committee says we need to reduce Nitrogen and Phosphorous in the Gulf by 45%. 

USGS says Illinois is the number one culprit.  It would appear that tile drainage is a big contributor to the problem at least of Nitrogen in runoff.  One interesting note was that even in areas where no fertilizer N was applied, nitrogen loss was still higher than desirable just because of high organic matter in Illinois soils.  Dr. Fabian Fernandez also has data that shows that Illinois Soil Phosphorus levels are higher than the agronomically justifiable level of 35 ppm on over half the soils in Illinois.  When P levels get that high, even small amounts dissolving in runoff can be a problem.

Where is this headed?  Maybe regulation, especially of P.  It looks like some incentives may be used as well.  Alternatives that could help reduce the Nitrogen problem are:  reduced usage, no fall application, cover crops, constructed wetland filter, and bioreactors.  Alternatives to reduce dissolved P are:  do not apply if levels are above 35 ppm, use sediment basins, use filter strips, till to reduce surface levels of P.  It is clear that in order to achieve national goals in improve surface water quality, there is a good deal of work to do.  It would appear that producers need to be even more careful than they have been in the past in order for goals to be accomplished without affecting production levels.