Cordell et al. (2009)’s paper on the story of phosphorous is a MUST
READ!
It is packed full of information on the subject… but I will try my best
to extract the useful information. Being half Moroccan (half Italian), I can’t help but rub my
hands with glee… the largest stores of P are locating in the country
(regardless of what anyone says, Western Sahara does not exist in Morocco; we
call the southern provinces… moving swiftly on…!) as shown in the figure below from Elser and Bennet (2011).
This is however a big
problem in terms of global securities and power balances. With turmoil in north
Africa and the apparent ‘revolutions’ reaching their 1st birthday, it
is more important than ever that food and the fertiliser used, does not fall
into the same fate as it did 3-4 years back with the large prices rises in
grains (Elser and Bennet, 2011). 700% price rise in P coupled with the price
rise signalled a warning light to governments worldwide. However, as Cordell et
al. (2009) and Elser and Bennet (2011) note, the world still is not reacting to
this train wreck; they can’t even pull their act together on gas emissions and
the Kyoto agreement (COP Durban 2011 round of talks).
One thing is for sure is that if we use less, costs will go
down and we are less dependent on another out-sourced commodity that everyone needs.
If we all became vegetarian, then we would require significantly less P than a
meat based diet, and most of the crop can easily be returned to the soil as
residue, recycling most of the P used as a fertiliser. Even so; the largest
wastage of P originates in the poor application of fertilisers to soils (8
million tonnes, MT). Leeching of the synthetically produced nutrients results
in massive inefficiencies in P management; contaminating ground, surface and
coastal waters with high levels of nutrients had led to vast amounts of
eutrophication.
Eutrophication is when nutrients (either via leeching direct
from fertilisers or poor waste management) added to water bodies causes the
growth of organisms; algal blooms are a common example of added nutrients
altering the natural ecology of a body of water (lake, sea, estuary, etc.). (Smithand Schindler, 2009) The blooms photosynthesis at high rates, starving most
other organisms of oxygen (increased when the blooms die and decompose);
creating a hypoxic environment.
Please read more on eutrophication in these sites:
- http://rtseablog.blogspot.com/2011/03/eutrophication-mapping-first-steps-that.html
- http://feastingonnaturalresources.blogspot.com/ This blog, by Megan Smith is great! She also talks about agriculture and environmental issues surrounding the wider debate. I highly recommend her post on Coastal Eutrophication – The impact of Agriculture in Chesapeake Bay
Back to wastes of P and as the figure above (Cordell et al. 2009) suggests, 14/17.5 MT
of P go to agriculture; of that only 3 MT make it to our forks. 8 MT is wasted
through poor application, and of the 3 MT we consume as food, 1 MT is wasted as
spoiled food. By just eating within our means we save 1 MT. through better
fertiliser management techniques with save an extra 8 MT. It is easier said
than done, but through accurate monitoring of soil nutrient levels, we can guage
whether or not the land needs to be fertilised, saving energy, money and effort
as well as P. Using more natural fertiliser we can solve some of the problems,
by no means is sh… poo a panacea for eutrophication/power
insecurities/commodity prices/waste management/agricultural productivity and
the like, but it is a step in the right direction!
Reserves of P aren't well documented globally, in fact many researches, scientists, geologists and
mad hatters disagree as to how much P there is under ground. Cordell et al. (2009)
explores this using a number of different scenarios showing just how long it
would take, depending on how much P we need, to finally hit the last nail on
the head of the coffin that would be global inorganic P reserves.
Next part coming soon!
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