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Thursday, August 9, 2012

Dissolved Phosphorous

My consultants' meeting in Lexington this week had a number of topics related to the environment.  Dr.  Tom Morris of the University of Connecticut Kicked off the topic with his discussion of disolved phosphorous in our surface waters.  Fingers are pointing to agriculture in relation to concerns in places like Chesapeake Bay and Lake Erie.  Some of those concerns are justified.

He pointed out that we all learned that phosphorous was only transported with soil particles.  While it is true that most phosphorus is move from agricultural lands in that way, there is a small amount of phosphorous dissolved in runoff that creates a big problem.  Livestock producers have been under pressure for a number of years to properly apply manure.  It looks like there is a threshold level of 150 to 200 ppm in soils that should not be exceeded.  Levels above the threshold can contribute to problem runoff even in fields that have not had manure applied recently.  He looks for this issue to stay around and he looks for it to be addressed at least partly by crop consultants.

Some of the consultants who work in the Grand Lake St. Mary's Watershed in western Ohio presented reports on their activities in the watershed. Their presentation tied in very closely with Dr. Morris's.  They pointed out that a lot of money has been spent on the problem already and a lot more is to be spent.  Even then it is unlikely to clean up the mess entirely.  One of the problems is that in shallow lakes like Grand Lake, nutrients continue to be mixed into the water from existing sediment even when runoff is clean.

My friend John McGuire put together a good summary of these issues for his blog in Farm Futures Magazine. 

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