[permaculture] Phosphorus Theft
Lawrence F. London, Jr.
venaurafarm at bellsouth.net
Tue Dec 8 17:07:04 EST 2009
Keith Johnson wrote:
> It is not merely the "current infrastructure of agriculture" that
> depends on phosphorus but all life on earth, i.e. the original
> infrastructure. It is a component of key molecules such as nucleic
> acids, phospholipids, and AdenosineTriPhosphate, and, consequently,
> plants cannot grow without a reliable supply of this nutrient. All
> organisms that eat plants also need phosphorus and we are included in
> this. It happens to be a nutrient that can be lost from soils and once
> it is gone it must be replaced. That would normally be done by cycling
> ANIMAL manures (especially from insect eating birds, and humans) back
> into the soil. If your soil doesn't have enough you will need to provide
> it. *Get a soil test.* The continents are "leaking" what they should be
> conserving and this loss generates vast dead zones in our oceans. Its
> for this reason that I have supplemented rock phosphates in my own and
> client's gardens. So far it's still relatively cheap despite substantial
> price increases.
> (snips from http://www.energybulletin.net/49686)
> *Mobilizing phosphorus present in the soil *
MAGNIFICENT POST, Keith! This added to a few others should become a
stick post (how would we go about building a collection of them? a
moderated companion list? this is as perfect use for a wiki). We should
do this and build a new Permaculture FAQ; the original, created by Steve
Diver is at ATTRA, a lot of the raw material for that FAQ was redived
from early discussion in this forum, the early 1990's).
Phosphate as rock phosphate and colloidal or soft phosphate ban be
bought in large quantities from Fertrell or in lesser quantities from
I won't quote the rest but I do have one comment.
> *Superphosphate fertilizers are made from chemically treated phosphate
> rocks. They are not recommended for use as they are highly concentrated
> and reactive. When applied on the field they react with calcium, iron,
> magnesium and aluminum, creating within seconds compounds that make
> phosphorus unavailable for plants. They may react also with trace
> elements, locking them up and causing deficiencies of micronutrients.
> Superphosphates are water soluble and they can be easily washed away by
> rains before plants have a chance to assimilate them, which later may
> cause the eutrophication of lakes and rivers. Not to mention that high
> concentrations of phosphorus in fertilizers (above 10) are lethal to
> mycorrhizal fungi.
Commercial, synthetic phosphate or its concentrated version
superphosphate is to be scrupulously avoided in the garden or on the
farm. At the plant is made by combining phosphate ore with sulphuric
acid and heating it to a high temperature in a "crucible" using
electrodes. Creating this product uses a lot of electric power.
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