The
Hidden Truth About Commercial Phosphate Fertilizers.
When I started farming
in the mid 50s, South East of San Antonio, The Texas A&M Ag and
animal experts both recommended using super phosphate (0-20-0) or bone
meal. Tests showed the soil low in phosphorus. Their recommendations
proved beneficial to the plants and the grazing animals.
In the late 60s, on my new
farm North East of San Antonio, the use of phosphorus again proved
productive. By banding colloidal phosphate in the furrow at planting, I
could double production on my fruiting vegetables. The rate applied was
two tons per acre. I never at any time noticed micro nutrient
deficiency. The soil Ph on the vegetable farm was from 7.3 to 8.3,
depending on where and when the testing was done.
Then, some time during the
70s lawns, shrubs, trees, vegetables and flowers in San Antonio started
yellowing from the lack of micronutrients. The problem was found to be
iron, zinc and manganese being tied up by phosphate. The extension
service started putting out bulletins telling everyone to stop using
phosphate.
I never experienced these
problems. But then, I had never used the new triple super phosphate that
was now on the market. I asked one of the agricultural extension agents
if the new 0-46-0 triple super phosphate could be causing all the
problems. He thought for a moment then mentioned that the timing
correlated perfectly but he never found anyone to agree.
On my own, I did several
tests. I used plants highly susceptible to iron colorosus. I planted
some in pure colloidal phosphate, some in pure rock phosphate and
another bunch in soil that I applied the equivalent of 10,800 lbs per
acre of the old style 0-20-0 super phosphate. All of the plants were
fertilized with bat guano, which has 10-3-1 (N-P-K) all grew normal,
showing no deficiencies. I strongly believed the problem to be the new
Triple Super Phosphate. But no one, either from A&M, USDA or the
fertilizer industry would or could give me an answer.
An elderly friend that had
worked for large fertilizer companies was visiting me one day. I asked
him for an honest answer to my suggestion that the new 0-46-0 could be
causing all the yellowing?
After a long pause he
answered. You are absolutely right but you are not supposed to know
that. He explained that the fertilizer manufactures made that discovery
but they kept it a secret and all agreed to stop selling and making the
0-20-0, type of phosphate. This also prevented growers from discovering
the problem by comparison.
To make 0-20-0, rock
phosphate is treated with sulfuric acid to make calcium phosphate
(0-20-0) and calcium sulphate (gypsum); these are two natural products
that seldom caused any problems.
To make 0-46-0, rock
phosphate is treated with phosphoric acid. With this, much higher
phosphate content, much higher N-P-K fertilizer formulas can be made.
Less needs to be used. And it sells for a higher price with much better
profits.
My elderly friend explained
that, when used, 0-46-0 is laying naked in the soil and looking for
something to marry up with. It bonds up with zinc, iron and manganese
then the plants can’t assimilate them.
Evidently, this knowledge
is well protected because to this day the agricultural agents are all
telling gardeners and horticulturists to stop using phosphate
fertilizers and manure for three to five years. Another problem, some
agricultural agents claim, is that the phosphate is causing lakes and
streams to grow too much algae.
I can’t understand their
reasoning. Manure has been used for centuries without causing soil
problems. However, if raw manure washes into lakes it will grow algae
because it is a complete fertilizer.
The fertilizer industry has
learned to beef up their high quality phosphate fertilizer products with
extra zinc, iron and manganese to help overcome the problems in the
landscape. Also, phosphate is not known to leach from the soil, it only
moves with the soil. It can’t get into lakes unless placed there or from
soil erosion. Phosphate alone will not grow algae; nitrogen must also be
present.
For answers I did some
research. I got virgin soil from a location that has never been plowed
or fertilized. I naturally air-dried and well homogenized this soil so I
could get identical samples to send to numerous testing labs. I sent
seven in all, two to Texas A&M soil test department and five to
other labs around the U.S.
The two A&M test
results showed excessive soil phosphate with instructions to not add any
phosphate fertilizer or manure to the soil for 3 to 4 years. The other
five labs showed soil phosphate low to medium and gave recommended
application rates.
Why are the A&M test
results so much different from the other five labs? Something is
definitely wrong here.
1. The algae in the lakes
should be attacked by stopping erosion and the over use of highly
soluble forms of nitrogen fertilizer.
2. The fertilizer
companies should be honest with their customers.
3. Texas A&M soil
testing department should get together with the private testing
industry to end mistrust and better serve gardeners and farmers.
4. The fertilizer
salesman should be honest and better educated.
5. More and proper
research needs to be done and shared with the farmers and gardeners.
6. The agricultural
agents should keep up with all private and public, research.
7. All educational
institutions need to teach more about Nature and how she
operates.
Malcolm Beck - May 2003
Note:
As of Jan. 20 Texas
A&M has admitted they were wrong in their testing and have now
made the proper corrections. To read the corrections go to
Laboratory
Extractant Change - http://soiltesting.tamu.edu./webpages/extractant.html
