permaculture

[Paul Cereghino <paul.cereghino@comcast.net>]

I am not aware of any generalized consciousness about phosphate except 
perhaps in the futures market.  I would generally assume that rock 
phosphate will be mined like crude oil... to the end.  Here is one analysis:

http://www.nhm.ac.uk/research-curation/projects/phosphate-recovery/p&k217/steen.htm
The data presented here, based on reasonable assumptions, suggests that 
within a time horizon of some 60-70 years about half the worldís 
currently economic phosphate resources will have been used up. 
Furthermore, current global phosphate capacity will be utilised at its 
maximum production level in 10 years. This may lead to a progressive 
increase in prices, both as extraction cots rise, as countries holding 
deposits become conscious of their depletion and scarcity value, and 
maybe above all because of increases in processing costs. The phosphate 
content of pre-beneficiated ore will continue to drop, leading to 
proportionately increasing quantities of waste and costs for disposal. 
Also, the degree of impurities will progressively increase as the better 
quality reserves are used up and this will increase processing costs.

80% of P rock is used for ag mostly in grain production
USA has 25% of estimated world resource, and 7-13% of est. reserves.  We 
also have a robust military, and so are likely to hold our reserves.  
Morroco and China account for the vast remaining majority of global 
reserves.


Different angles this could go:

-If you own land, build your in-soil P reserves now while it is cheap 
and clean
-Bone is a long term repository of phosphorus, with animals as mobile 
phosphorus collectors.
-Marine derived nutrients, particulalry fish bones, offer an opportunity 
to recover lost nutrients, however global fisheries are under enormous 
stress already before we go strip mining the oceans for phosphorus.
-Deep rooted plants can bring phosphorus up from deeper soil layers.
-Fungal symbiants are important for phosphorus harvesting in woody plants.
-Some species likely are dynamic accumulators of phosphorus 
(aggressively absorb more than necessary for metabolism), and could be 
intercropped or used as a catch crop or in cut-and-carry agroforestry 
practices.
-Alternate carbo sources other than grains may be lower P demand.

~Paul Cereghino, Puget Sound, USA


Lawrence F. London, Jr. wrote:

> What is being done to conserve phosphate resources globally?
> Is usage of mined phosphate, a non-renewable resource, being prioritized 
> according to any conservation strategy?
> Is it being recycled intelligently in agricultural systems?
> Is is still used in the manufacture of soft drinks and if so, why is that 
> allowed?
>
>
> http://www.ars.usda.gov/is/pr/2006/061129.htm
> Adjusting Fertilizer to Create Low-Phytate Crops
> By Don Comis
> November 29, 2006
> Giving too much phosphorus to wheat and barley plants has been shown to raise 
> the amount stored as phytate, rather than
> as more digestible forms of phosphorus. This finding is important for two 
> reasons: Livestock that are fed high-phytate
> grains excrete more phosphorus in their manure, which can pollute water. 
> Also, phosphorus is a finite resource that
> could be irreplaceable once it has been thoroughly mined—which could happen 
> in the next 25 years.
>
>
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