NUTRIENTS - CONTROLLED SUBSTANCES

So the cat is out of the bag. Only about more than a decade late. The Everglades Foundation – RTI study report. Nutrients in waters, phosphorus, etc.etc. Haven’t we known that intensive agricultural activities, the way they are practiced nowadays, pollute ? Yes, only thanks to the intensive applications of fertilizers can we hope to produce the effective acre-quantities of crops as agriculture does it now.
And this is how it comes that Phosphorus – and Nitrogen, and sulfate, and other nutrients – run off the agri-fields in soaring quantities and find their way into our surface fresh-waters and even estuaries. Throwing natural systems, and particularly the sensitive ones such as the Everglades, completely out of balance – and threatening our fresh water supplies and, indeed, our very livelihood and civilization. The situation is particularly threatening the Florida peninsula and with it more than 8 million people that live on it.
IN and OUT – a Simple Mass Balance
The recently released RTI International study for the Everglades Foundation only confirms what has been suspected, known, all along. Phosphorus and the Everglades ! Now we have the figures, numbers, tables, diagrams – the whole works to document it. The study long overdue that should have been done by the government a long time ago. But – yes, it is a “sensitive issue” – agribusiness is so important – and so powerful (a lobby) particularly in Florida.
Yet, it is all so simple: excessive phosphorus quantities IN, excessive phosphorus quantities OUT – and right into Florida canals, Florida fresh-water, the Everglades, the estuaries - -
A simple mass balance.
Accounting for Phosphorus
All that more surprising is that all that phosphorus has not been really accounted for. And where does it come from ? It is brought onto the land in truck-load quantities by the farmers – to assist growth. And to be washed off by rain – in field run-off.
What needs to be also mentioned is the “time-bomb” of phosphorus accumulated on the land and in deposits of lake bottoms over the years of using fertilizers.
From tedious long-term monitoring, we do know how much phosphorus runs off the land. Overall, and actually even down to the individual farm areas. A somewhat unknown, yet crucial, factor is just how much phosphorus gets assimilated – in the crops, by the land itself. That factor can vary a great deal, locally.
Removing Phosphorus
So, while crucially important, phosphorus on the loose poisons our water bodies, our fresh water all the way ‘down’ to estuaries. While trying hard to remove it (farmers’ BMPs, constructing STAs) spending millions of dollars, why don’t we control it better ? The RTI report also shows that is much cheaper (8 times !) to control nutrients “at the source” (BMPs) rather than trying to remove them (by the STAs) when they already escaped into the environment.
Controlled Substance ?
If it is so important, why don’t we just simply declare phosphorus something like a CONTROLLED SUBSTANCE – and monitor its purchases and field applications. That would certainly be easy to do – every farmer already knows exactly how much fertilizer he/she bought and where was it put, why and when. If we know how much phosphorus went IN and how much flows OUT in the field run-off – we can complete our calculations, do all the accurate environmental modeling and remove the gross uncertainties that plague us now.

Having a better knowledge of phosphorus quantities, we can meaningfully control it – and optimize its uses as well as its effects in the environment. Easy, effective and particularly – economically attractive.
The keyword to remember: CONTROLLED SUBSTANCE.
And handle it correspondingly.