Subject: BD Now! Soil EC meters to measure phosphorus and more.... Univ of Missouri research

From: Steve Diver <[email-masked]>
Date: Wed, 21 Apr 2004 16:49:29 -0500

Scientists Explore Applications for Soil Conductivity Testing
Missouri Ag Connection - 04/16/2004
http://www.missouriagconnection.com/story-state.cfm?Id=225&yr=2004

When the concept of soil electrical conductivity was first introduced, 
some scientists
called it "a solution looking for a problem." There is no longer a 
shortage of problems
to which soil electrical conductivity (EC) can be gainfully applied. It 
can measure
topsoil depth and texture, organic matter, water holding capacity, 
salinity and
other important factors.

Many people are unaware that soil conducts electricity, or that a 
measurement of
that conductivity can provide valuable information. Because water, salts 
and clay
particles conduct better than soil air pockets, organic matter, silt or 
sand, soil
EC sensors can provide useful soil profiles at a fraction of the cost of 
conventional
grid sampling.

To map soil EC, a soil EC sensor is combined with Global Positioning 
Systems,
and observations are collected on-the-go over a field. There are two types
of equipment used to measure soil EC. One uses electrodes that penetrate 
the
soil and emit an electric current while another electrode pair senses 
and records
the electricity conducted from one set to another. The second method 
induces
a magnetic field into the soil profile while a sensor mounted behind the 
towing
vehicle measures the current and collects the data. Both can generate maps
of soil EC that can be profitably compared to yield maps and other data.

One recent application of the technology is to determine the amount of soil
phosphorus in different parts of a field to which poultry litter has 
been applied.
As stricter regulations are implemented regarding the disposal of animal 
waste,
poultry producers will need to manage the waste more efficiently to reduce
the risk of environmental contamination. Over-application of poultry litter
on crop or pasture fields results in high phosphorus content that can 
pollute
streams, lakes and reservoirs.

Scientists from the University of Missouri and Oklahoma State University
teamed up with state and federal agencies to see whether soil EC 
measurements
could efficiently estimate whether soil is low enough in phosphorus to bear
more applications.

etc.......

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From: Steve Diver <[email-masked]>
Date: Wed, 21 Apr 2004 17:23:07 -0500

I thought this was interesting, because the pocket EC meter
is used in ecofarming.

Pike Agri-Lab Supplies has an interpretive chart that
shows plant tissue sap tests based on EC, pH, and Brix.

Bruce Tainio has a chart on BrixTalk that shows
optimum plant sap pH..... correlated to anion or cation
storage problems and susceptibility to insect and disease
attack.

Under ecofarming, you can adjust with soil and foliar
amendments to enhance crop vitality.... thus avoiding
pests and  disease.... thus enhancing food quality and
Brix and so forth.....  at least that's the idea...

Did you know that Tainio uses the pH chart, but the
original work is based on frequencies of all the atoms
combined?

Interesting correlations here and there....  

Not really sure how this Missouri test works, but there
might be a connecting idea to pursue some day...

Steve Diver

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From: Steve Diver <[email-masked]>
Date: Wed, 21 Apr 2004 16:49:29 -0500

etc.......

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From: Steve Diver <[email-masked]>
Date: Wed, 21 Apr 2004 17:23:07 -0500

Steve Diver