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highyields
Senior Contributor

Glyphosate and Algae bloom

Now my chemistry isn't the best anymore and I don't have all the answers to answer my own question, but could Glyphosate contribute enough Phosphorus to contribute to the phosphorus levels in bodies of water that cause Algae bloom.   Now when I look up Glyphosate on Wikipedia http://en.wikipedia.org/wiki/Glyphosate it shows a "P" molecule in the chemical break down. And according to this link http://www.monsanto.com/products/Documents/glyphosate-background-materials/gly_phos_bkg.pdf  glyphosate breaks down to an inorganic phosphate/phosphoric acid..    

 

I'm not suggesting anything but as phosphorus fertilizer rates have been trimming down in the past 30 years and since the year 2000 algae blooms have grown in size, that also corresponds to the higher use of glyphosate base herbicides.  

 

The reason I question the finger pointing towards fertilizer runoff is why now??  If the use of phosphate fertilizer is falling,,,and according to what we have been taught the Phosphate gets "collected" by the cations in the soil and isn't released into the soil,,, this is a link to the Web site of Penn State publication, best one I found,  they say it "runoff" and pollutes, if it can run off the soil why is it not available to the plants growing?   http://extension.psu.edu/plants/crops/nutrient-management/soil-fertility/managing-phosphorus-for-cro...  

You should read the publications because they talk out of both sides of their mouth,,,one says little chance of runoff but yet in the next paragraph it states that phosphate can pollute water...

 

I still question the blame that farmes are getting for this one.   

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5 Replies
buckfarmer
Senior Contributor

Re: Glyphosate and Algae bloom

Yep I've said it before. There are a few lakes here in Ohio that had blooms. Guess what!!! No farms in those watersheads. . Blame whoever you want. I'm not buying any of it till someone proves it.
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farmerguy89
Advisor

Re: Glyphosate and Algae bloom

What!!

The amount of phosphorous in a Liter of roundup is much less than 1 years application of map. I doubt you even get a lb of phosphorous from roundup. Maybe mg?

Anyways fertilizer is far more likely
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Kay/NC
Honored Advisor

Re: Glyphosate and Algae bloom

Water quality people talk about "fate and transport" of phosphorus. MIght be a good phrase to Google. 

 

Here in NC, one of the add-ons to our Comprehensive Animal Waste Management Permits is a PLAT (Phosphorus Loss Assessment Tool).  A few years back, each hog farm was assessed, most by NRCS I feel certain, to see what its potential was to have off-site impacts for P.  The PLAT was calculated on matters such as soil type, slopes, type of grass cover crop or row crop being produced, etc. 

 

Ranking low, as we did, meant we could remain on an N-based management poaln for our manure effluent.  Ranking such that you posed a threat for off-site P transfer, you got moved to P-based planning.  That requires MUCH more acreage for nutrient uptake, and can result in reductions of stocking densities.  That means you cannot raise as many animlas, thus cannto make as much money. 

 

Do not forget the impact of municipal waste on watersheds.  Sewage treatment plants often transfer solid from the treatment process to land application sites, and that is a LOT of nutrient being spread.  Some is managed well, some not...and I know whereof I speak here. 

 

While Roundup and its ilk might have a part on the play, it isn't the only variable.  Possibly the re-entry of marginal land into production, out of CRP...usually hillier, tougher soils, etc., could also be a factor. After being idled, those acres essentially needed a shot of fertilizer to get going, and may have required more per acre that optimal crop soils and slopes, or may have taken up what was applied less efficiently. 

 

Drought can result in fertiliizer not being utilized by plantsm too, and thus excess available to run off.  Heavy rains in relation to timing of manure or fertilizer applications can result in less absorption by the soil, for plant utilization. 

 

More tile installed, ditto?  Just asking....

 

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highyields
Senior Contributor

Re: Glyphosate and Algae bloom

the sewage solids are something to consider..  I thought around here I was told there was 200 lbs of N and over 100 lbs of P if I remember correctly

 

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Kay/NC
Honored Advisor

Re: Glyphosate and Algae bloom

When you mention algae blooms, it just struck a chord with me.  My husband's farm in VA has several nice ponds, and the land there, all in pasture now,  has received biosolids two or three times in the past few years (application is supposed to be no more frequent than every third year, in Virginia, unless rules have changed). 

 

We had not been on the place much, until last year, for almost twenty years.  I noticed that some of the ponds were totally covered with algae last summer.  That would be the main difference in the way the surrounding land, which sheds into the ponds on rainfall, has been altered in over a decade.  Row crops were prevalent before then.   

 

You might look for permits in the affected watersheds, for biosolids application increases.  Also, I think that commodity prices have possibly pulled a LOT of land out of CRP. 

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