BOARD02267

• Board Meeting Date: 5/27/1968
• Description: Agenda or Table of Contents, Minutes, Memos
• Board Meetings - Doc Type: Meeting

I

In addition to this, of course, consider-
able work dealing with techniques for causing
that plant itself not to transpire so much.
Actually the figure runs something like one per-
cent of the water that a plant transpires. So
it itself is very, very inefficient and a
tremendous potential for the available area if
the problems could be solved. Whether they can
or not, I don't know. Certainly cover has an
effect on this, heat temperatures have an effect
on this and this kind of thing, so we have been
working with ground covers and so forth as to
their reflective tendencies, their color wave
length that is coming back to the plant and
this type of thing, as to that effect on trans-
piration by the plant.

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All right, we have developed a history
in this kind of thing. Furthermore, in 1966
the Agricultural Research Service of ~he U. s.
Department of Agriculture had a fairly large
project going in eastern Colorado qealing with
the movement of nitrates through the soil down
to the water table. A problem, of course, that
everybody has been aware of recently. We cooper-
ated in this project. Our contribution particu-
larly was one of developing a technique for
measuring water flow through the soil at con-
siderable depths on the order of magnitude of
1/10 to 100 centimeters per year, very slow
rates. The technique involves simply obtain-
ing a core at these depths and the machine was
already available for doing this as a result
of the Agricul~ural Research Service project,
where we can go down ten or fifteen feet,
obtain a soil core sample, bring it up, bring
it into the laboratory. By centrifugation and
weighing with very accurate an~lyttcal balan~es,
we can get at the actual hydraulic conductivity
of this sample at the moisture content it was
at when we obtained it. Assuming that if we
are sufficiently below the root zone and
sufficiently above the effects of any water
table, we have lots of areas of this type in
eastern Colorado to work with, we can assume
that we have a unit potential gradient down at