This is a public-interest archive. Personal data is pseudonymized and retained under GDPR Article 89.

Re: ?

Mary Jane Hatfield wrote:
> 
> A friend asked me...
> 
> "I had a message from a woman asking for documentation (a
> source to site) for the statements :
> 1- Native prairie soaks up ~12 inches of precipitation/hour ---
> 2- less than 1% of native prairie is left in Iowa
> the number I usually hear is "less than .1 of 1% or less than 1/2 od 1%
> of Iowa's native prairie remains"
> I think how they define native prairie is important in backing the
> numbers-"
> 
> Can anyone be of help?
> 
> Thanks.
> 
> MJ Hatfield
> 
> ---------------------------------------------------------------------
> To sign-off this list, send email to majordomo@mallorn.com with the
> message text UNSUBSCRIBE PRAIRIE


I want to stand corrected on the potential of a native prairie to
infiltrate up to 12" of water per hour.  I visited with one of my
agronomist colleagues in Missouri who ran some infiltration tests on a
Mexico silt loam in near Columbia, Missouri.  He ran these tests under
three conditions 1.  a conventionally tilled corn-soybean field
                 2.  a no-tilled corn soybean field
                 3.  an unaltered stand of native prairie vegetation

He used a device called a ring infiltrometer which is a metal cylinder
that is depressed partially into the soil surface with 6 inches left
above the ground.  He filled the cylinder with water and recorded the
time that it took to soak in.  

I don't recall his exact measurements on the conventionally tilled corn
and soybean field but the no-till field had ten times the infiltration.

On the praire soil, he applied six inches of water which emptied his
water vessel.  By the time he could obtain more water from his truck (
parked just 25 feet form where he ran these tests) to refill the
cylinder the water had already soaked down into the prairie soil.  He
refilled the infiltrometer a second time and went to fetch more water
again and the second six inches soaked in in just a few seconds!  he
never did establish an accurate reading on the infiltration rate of the
prarie soil because he couldn't take the readings because he had to keep
getting more water.  It is safe to say that this soil was intaking 12"
of water in an hour easily!  An important note is that Mexico silt loams
are claypan soils!  That is that they ultimately are limited in their
infiltration due to the impeding clay layer in the subsoil.  The effect
that several thousand years of prairie vegetation on the porosity of
this soil is amazing! 

Brett Roberts

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@mallorn.com with the
message text UNSUBSCRIBE PRAIRIE
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index