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Hi everyone- My name is Sharon Davis I am a PhD student in the
Cooperative Research Centre for Catchment Hydrology at Monash
University, Australia. I have an honours degree in Physical
Geography (Geomorphology) and am now discovering the wonderful world
of soil physics. My project is still in the early stages, however,
my general areas of interest are the scaling problems associated
with measurement of soil hydraulic properties both in the field and
laboratory.

At the moment I am compiling a literature review on the removal of
large undisturbed soil samples from the field for laboratory
analysis of hydraulic properties. If anyone has some interesting
ideas or references I would appreciate any feedback...Also, I am
planning to undertake an Instantaneous Profile Method experiment
(transient state internal drainage method to measure unsaturated
hydraulic conductivity) in the field (forested site) in the coming
months if anyone has some experience in this technique it would be
great to hear from you.

Sharon Davis

I'm a student on the first year of the PhD in Earth Science.
For my thesy I'm studing the volcanic soils and paleosols in S. Miguel
island (Azores - Portugal).
On this island there are typical andosols, very interesting for the
neoformation of clay mineral, the mass balance through the soil profile,
and the paleosols these last oneinteresting for the investigation about the
quaternary climatic variation.

Francesco Malucelli

___________________________________________________________
Dipartimento di Scienze Geologiche
Universita' di Bologna
Via Zamboni 67 40127 Bologna Italy
Voice: +39-51-354561
Fax: +39-51-354522

E-mail: malik@geomin.unibo.it (internet)
E-mail: 38144::doc2 (decnet)
___________________________________________________________

Dear Soils-l subscribers,

It has been two weeks since the creation of this list and I am quite pleased!
We now have over 170 subscribers and the rudiments of some discussion
topics in the works. I would like to again offer my apologies to those
charter members of the list who were receiving those nasty Operator
messages at an alarming rate. I deduced that the problem could be solved
by unsubscribing then resubscribing to the list. If anyone is still
having trouble, please let me know. I aim to please!

I would like to thank the 20 people who have taken time to
introduce themselves to the list.

Jess Lowenberg-Deboer <LOWENBERG-DEBOER@agecon.purdue.edu>
Donald A. Friend <AHDAF@asuvm.inre.asu.edu>
Kirk Iversen
Theresa (Tess) Gidley
pbb@hanover-crrel.army.mil (P. B. Black)
zeitler@ariel.tamu.edu (Jon W. Zeitler)
jgrant@lnsc.lead.org (Joseph Grant)
Bandi Hermawan <hermawan@unixg.ubc.ca>
Alioune Fall <fallalio@student.msu.edu>
Xuhui Lee <xhlee@unixg.ubc.ca>
Meredith L Wessells <mwessell@magnus.acs.ohio-state.edu>
timothy m demko <demkot@gas.uug.arizona.edu>
Deborah Neher <deb@essnvd1.arrc.ncsu.edu>
wesjennings@attmail.com (Wes Jennings)
M. Snethlage <M.Snethlage@frw.ruu.nl>
J.Kaduk <kaduk@dkrz.d400.de>
Timothy C. Strickland <STRICKLAND@CSRS.ESUSDA.GOV>
Will P. Gates
Sharon Davis
Francesco Malucelli

All of the introductions have been quite detailed and very informative.
For everyone else out there who haven't yet made their introductions,
please don't be shy. A brief introduction listing your name, your
affiliation and areas of interest and/or expertise and some thoughts
of possible discussion questions would be enough. Don't let the longer
introductions scare you off. Also, if you have been impressed by the
level of expertise, don't let that scare you off either. I envision
this list as facilitating the exchange of information and ideas and
those less experienced can hopefully gain from the aggregated knowledge
available on the list. In other words, let us know what you want to know!

Now on to some administrative details. The digest option is now available
for the list. Instead of receiving many separate mail messages, now you
can get your soils-l mail in one tidy package with a header at the
top listing the subjects discussed. Of course, the list traffic is
hardly staggering at this point, but in case you would like to receive
the digested format, just send an email message to listserv@unl.edu
with the one line message:

set soils-l mail digest

The list archive is now available. To get a file containing all the
messages posted to the list since it began, send email to listserv@unl.edu
with the one line command:

get soils-l log9311

In the future, the archive file names will be of the format logyymm
where yy is the last two digits of the year and mm stands for the month.
For those of you who have just recently joined the list, check out the
archive to see what you have missed. Don't worry; the archive does NOT
contain the Operator messages!

Finally, some possible topics for discussion have been raised through
the introductions. Here is a synopsis as I see it:

1. There was a question as to the state of knowledge concerning
soil quality factors in the vadose zone.

2. What is the current state of Variable Rate Application Technology?
What is commercially available and how are farmers reacting to it.

3. Who has had experience with arid land slope deposits?

4. What process models of nitrogen, microbial and/or plant dynamics
in saturated substrates are available?

5. The physics of ice formation in porous media.

6. The integration of meteorolgical data and soils science.

7. The use of cover crops to improve soil structure and prevent
soil erosion.

8. How can laboratory determined soil physical properties be related
to conditions of soils in farmers fields [soil tilth? -jp]?

9. The long-term continuous determination of soil H2O and CO2 fluxes.

10. Soil nutrient, microbial and physical property dynamics as affected by
inorganic and organic nitrogen amendments (with earthworms on the
side!).

11. The interpretation of Paleolithic carbonate horizons in arid environments
and their associated isotopic signatures.

12. The study of nematode populations in relation to soil quality.

13. The use of non-traditional (egad! non-scientific) methods for
relating soils information to agricultural, engineering, etc.
applications.

14. The usefulness of simulation models in agricultural development.

15. The relationship between global vegetation biomes and soil carbon.

16. The impact of mid-western flooding on soils.

17. Instantaneous Profile Methods (transient state internal drainage
method) to measure unsaturated hydraulic conductivity in the field.

18. The study of andosols and clay mineral formation under volcanic
conditions.

Here are a few of my own:

- What data exists concerning nitrogen content of crop roots
and the proportion of the total plant nitrogen which exists in the roots?

- What future do you envision for soil scientists?

- What things can be done to make this list more useful for you?

The above questions and discussion topics were gleaned from a review of the
archive and the introductions. I hope I have interpreted your interests
correctly. To generate more traffic and facilitate the transfer of information
I would appreciate it if people would carry on their discussions on the
group. I myself am guilty of responding directly to persons who have posed
questions but I realized I was leaving the rest of you out when I did that.
Many list subscribers (myself included) are 'shy' and don't feel
comfortable exposing their comments to a large number of people. I hope
that the majority of list subscribers will be accomidating of the
variety of experience that resides on this list. I don't envision this
list as a place for flamefests. If you like controversy, check out the
news.* groups on Usenet!

Well, this letter has been kicking around in my head for some time now
and I hope you haven't been overwhelmed. I am very pleased with the
status of the list and see that there was a need for soils-l to be
created. I hope the traffic picks up.

Yours truly,

Jerome Pier List Owner
jp@unl.edu

Hello Folks,
My name is Daniel Potter and I'm an archeologist at UT Austin and a grad. student at Harvard. I've been involved with archeological stratigraphy for a number
of years (about 20), but have had very little training in soil science, a fact
I regret very frequently. Thus, I come to this group as an outsider, but one
who is very interested in learning, and who believes that archeology and the
soil sciences have much to offer each other.

My current interests in this regard:

1. How pedogenesis and pedoturbation effect the archeological record.
2. Soil/biota/climate systems of the Holocene.
3. Holocene landform evolution.

My areas of geographic interest are (in order of expertise) Central and south
Texas, Mesoamerica, and US Midwest.

I look forward to learning and participating in those areas of mutual interest.

Regards,

Dan Potter
Texas Archeological Research Lab.
UT Austin
Balcones Research Center #5
Austin, Texas 78712-1100
(512) 471-0963

I tried to send this directly to Will Gates, but failed.
Since you suggest everyone would like to be in on these

discussions, and in fact, if anyone else has interest in this
subject, your input would be appreciated, I'm sending it to
the list, hopefully by answering your message.
I'll send my own introduction ASAP.
------------- Begin Forwarded Message -------------
Date: Thu Dec 2 10:49:31 EST 1993
From: Jeri L BERC <!a16jberc>
Phone: +1 202 447 8578
Subject: Floods
To: internet!bdwg@cso.vmd.uiuc.edu
Cc: Jeri L BERC <!a16jberc>
Content-Length: 545

Hi Will,
The Soil Conservation Service in Illinois would be very interested
in any information you might have on long term impacts on soil
productivity of management practices (deep tillage) to remedy surface
texture problems created by the floods. If you know of any research,
or are interested in exploring the problem, please contact Ray Herman
State Resource Conservationist, SCS 1902 Fox Dr. Champaign, ILL 61820-
7335 217 398-5268.

Thanks very much.

Jeri Berc, National Research Coordinator, Washington DC
internet!attmail.com!a16jberc

Hello !

I wanted to keep silent for a while to see the interest fields of
the other members. As I thought, my field of interest (though it is
related to soil) is bit deviate from the others. Anyhow, recent
posting in the list made me intiate to write this.

I'm a Ph.D. student reading on soil stability problems mainly
slope stability, bearing capacity, earth pressure etc. It has
to do much with Engineering aspects of soil rather than
agriculture. We (including my self, my supervisior and some
of other graduate students in my lab) modified a kind of
limit equilibrium method for analyzing above mentioned stability
problems. At the moment, the method is fairly reasonable and
simple enough to get through even for a practical engineers.

Sorry if I'm out of your taste. If there is any one in the
list like me, I like to discuss about the weak points in the
conventional analytical methods in soil stability problems
and possible developments.

thanks for your patience and good luck to all of you.

Jayalath
jayalath@dpc.ehime-u.ac.jp
(I didn't use any special software for typing this message. If
there is any error ;-), sorry.)

Dear Soils-l subscribers,

My name is Ernest Lopez-Baeza and I am an A/Professor (Profesor Titular de
Universidad) of Applied Physics at the University of Valencia (Spain).

Firstly, I would like to congratulate Jerome Pier and everyone of us for the
success of this list.

My overall research area of interest is Climatology from Satellites, mainly
the study of land-surface processes, and specifically surface radiation
balance. I am trying to study the correlation between net radiation and
climatological and agronomical parameters (NDVI, biomass, LAI, ...) in two
different environments, namely semiarid areas and areas affected by forest
fires. For the first one, I am involved in a CEC project called EFEDA that
you may have heard of. EFEDA stands for ECHIVAL Field Experiment in a
Desertification-threatened Area, and ECHIVAL stands for European Programme
on Climatic and Hydrological Interactions between Vegetation, Atmosphere and
Land-surfaces. In this project I would like to study that correlation
for dry land - irrigated conditions. In principle, for semiarid areas, one
may assume that net radiation and soil heat flux are the important terms of
the surface energy balance, and here is where soils play a good role.

Since my background from Doctorate is on heat conduction, I am interested in
studying the correlation mentioned above according to soil thermal properties,
mainly thermal diffusivity. Soil moisture content becomes then the key
parameter but as for now I cannot get a TDR equipment to get the soil moisture
profile. Then, according to the invitation of the list owner, I would like
to ask the following introductory questions:

1. How could I measure soil moisture PROFILE simultaneously with soil
temperatures.
2. I would like to measure the soil dielectric constant to get soil moisture.
Then, what effects could have a saline soil on the measurement of the
dielectric constant?

Since this field of work is new for me, does anybody of you have some
references on the questions above?

Thank you very much for your time.

Best regards,

E. Lopez-Baeza

*******************************************************************
Dr E.Lopez-Baeza email: lopez@vm.ci.uv.es
Dept de Termodinamica tel: +34.(9)6.3864300 ext. 3279
Universitat de Valencia (Spain) fax: 3642345
*******************************************************************

Hello to all.

My name is James Tindall-my friends call me Jim.

I am an unsaturated zone hydrologist employeed by
the U.S. Geological Survey, National Research Program, Water Resources
Division in Denver, Colorado, USA. I have a Ph.D. in soil physics and my
interests are in chemical transport in the vadose zone from the soil surface
to ground water, including the root zone portion. Also, I am working in
colloidal facilitated transport, fractal flow of water and nitrate cycling
in the unsaturated zone. I have experience in measurement of most vadose
zone properties including TDR and neutron for theta content, soil pressure,
soil temperature, unsaturated K, tracer movement, etc. I have run several
instantaneous profile tests and have developed an intact core procedure
for extraction from the field and analysis in the laboratory.

To try to be brief, I am interested in all forms of transport, and the
influence that physical (including preferential flowpaths), chemical, and
biological processes have on the movement of herbicides, nitrates, and
other contaminants. Most of the research I perform in the field and lab
are fully automated to try to link unsaturated K to transport. Thus, I
use homemade tensiometers attached to a CR10 (Campbell Scientific)
datalogger via a micro-switch transducer pressure sensor for measuring
soil pressure over time, suction lysimeters, gas port samplers, etc.
My TDR is also multiplexed, etc. Not that my
advice would be that great, but I would be willing to offer any assistance
I can to those who are interested in work in the vadose zone. Enjoy your
research.

Jim Tindall

I am a new subscriber to the soils list and have been reading the introductions
with interest. I would like to thank Jerome for the opportunity that all list
members now have to rapidly share ideas in related research areas.

Dear List members,

I would like to take a minute to re-emphasize the broad scope of subject
matter which may be discussed on this list. I have recently read several
cautious and apologetic introductions from persons who are not 'traditional'
soils scientists. There is no constraint whatsoever on what may be discussed
on this list a long as it pertains in some way to soils science. Likewise,
you do not need to be a soil scientist to subscribe or post messages to
this list. I have been surprised and pleased at the great diversity of
expertise as noted in the introductions so far. I am thrilled that there
are persons who are participating in this list who do not have a soils back-
ground but feel that soil science has some bearing on their research, job,
whatever. The whole point of the list as I envision it is the transfer of
information. Just as it is important for soil scientists to consider
economic, social, etc. factors in their research, I feel other disciplines
should be aware of the importance of soils.

The only constraints I place on this list are no flamefests and no personal
communication; these should be carried out through private email. Also,
the subject matter should in some way pertain to soils but if one sees the
diversity of topics which are discussed at the National Soil Science Meetings,
then it is clear that a wide range of discussion is possible. Don't be shy!

Jerome Pier jp@unl.edu

I would just like to introduce a few people to each other and I hope no
one minds if I do this from time to time. Recently, Sharon Davis described
research she was performing regarding the Instantaneous Profile Method
and wondered if there was anyone on the list who had experience with this
method. After reading Jim Tindall's introduction, I would think the two
of you certainly have a shared area of interest. Also, a colleague of mine
Laosheng Wu working with John Baker at U. Minnesota has been using this method
in sandy soils. Laosheng was not on the list at the time Sharon posted
her introduction.

I would recommend to those that have recently joined the list that they
get a copy of the list archives to read introductions they have missed.

Send email to listserv@unl.edu with the message:

get soils-l log9311

and you should receive a text file of all the messages posted to the
list during the month of November.

Jerome Pier jp@unl.edu

I would like to ask the list if any of you are familiar with a new
technique developed by Bill Hook to use diodes placed in a TDR probe
to act as a very fast switch so that two waveforms are created which
can then be differenced thereby 'cleaning up' the TDR wave. The method
is discussed in:

Hook, W. R., N.J. Livingston, Z.J. Sun, and P.B. Hook. 1992. Remote
diode shorting improves measurement of soils water by time domain
reflectometery. Soil Sci. Soc. Am. J. 56(5):1384-1391.

I would like to ask if anyone has had experience with this device
and what impressions do you have about the method.

Jerome Pier jp@unl.edu

SET SOILS-L NOMAIL

soils-L nomail

Dear list subscribers,

With people leaving their terminals behind for the holidays
and since we don't have a ring of geosynchronous communication
satelittes to provide us with email anywhere on earth (sniff!)
many of you will want to suspend the delivery of list mail
to avoid having a run in with your SysAdmin. (What do you mean
I have 2,347 mail messages? I am only subscribed to startrek-l!)
It would appear that there are several flavors of listserv out there
and the commands differ slightly. I am beginning to see people
posting set nomail commands to the list much to their embarassment.
This is not worthy of capital punishment but it does cause confusion
when the subscriber is still receiving mail even though he told]
the server to stop his mail.

Please remember that you send all list commands to listserv@unl.edu
and not to the discussion address. Also, to temporarily suspend
delivery of list mail, send the following command to listserv@unl.edu

set soils-l mail postpone

and substitute agmodels-l where appropriate.

When you get back from utah and are sitting in your chair with your
leg in a cast and want to read your mail, send the following
to listserv@unl.edu:

set agmodels-l

and this should restore everything to default values.

Note: the above was written in a lighthearted manner and no
offense was intended nor was this post directed at anyone
in particular. It is friday afternoon afterall!

Bye,
Jerome Pier jp@unl.edu

I am a soil scientist with the USDA-Agricultural Research Service,
stationed at the Soil Science Department at the University of Minnesota.
My main professional interests involve nitrogen cycling in soil-crop-animal
systems that include forage legumes (Medicago sativa, Lotus corniculatus,
etc.) and large herbivores (dairy cows, in particular). Current research
includes (but is not limited to):
1) measuring root production and decomposition in living alfalfa stands
using minirhizotron technology to (to determine the importance of this
pathway of symbiotic N loss);
2) selecting alfalfa plants with rapid root elongation rate for use in
rapidly exploring and ultimately removing nitrate from subsoil;
3) assessing nitrate leaching losses from grazed and nongrazed forages;
4) determining the effect of nitrate on symbiotic N2 fixation in alfalfa;
5) improving animal manure use on dairy farms, e.g., by minimizing losses
through pathways that are most environmentally detrimental.

* Most burning question: *
Who has a dependable model for water and nitrate flow under field
conditions under perennial crops (i.e., one that is fairly accurate at
predicting actual uptake and movement of nitrate)?

* Next most burning question: *
Can the model handle inputs of urine and feces typical of pastured dairy
cows?

P.S. Jerome, you ask about root N concentrations. We have done some
work on forage legume roots. Fine (nonsecondarily thickened) alfalfa roots
contain about 240 micrograms of N per meter of root length. We found that
this value was independent of root age, and we saw no decline during
senescence. Fine birdsfoot trefoil roots contain about 140 micrograms per
meter. In both cases, N concentration declined with age for a few weeks,
but corresponding increases in mass also occurred. If specific root N
concentration of forage legumes is relatively constant, it makes
calculation of N inputs through roots easy (providing you have root lenth
measurements).

In related work, we found that root N concentration was almost always
affected by soil contamination, even when roots had been sonicated in a
buffer solution to remove adhering soil. Thus, literature values for roots
need to be examined to assure that the methods included correction for soil
contamination. We have taken the approach of using the sample C conc.,
rhizosphere soil C conc., and assuming that the noncontaminated root
contains about 45% C. Any decline in sample C conc. from the assumed 45%
is deemed due to soil. After solving a C equation for soil
contamination, we use rhizosphere soil N conc., root sample mass and
measured N conc., and calculated soil contamination to estimate actual root
N conc. We are testing this approach now by using titanium as an
alternate "tracer" for soil contamination. Soil contains on the order
of 3000 mg/kg and plant tissue contains about 3 mg/kg. Using our
correction approach with C, root N concentrations range from about 20 to
45 mg/g for nonsecondarily thickened alfalfa roots, depending on age. For
thickened roots, we find values of 7 to 25 mg/g. Of course, in autumn,
N conc. in thickened roots may increase as the plant prepares for
winter. Thus, it is difficult to answer your question precisely -- it all
depends.....
----
Michael P. Russelle
USDA-ARS
439 Borlaug Hall
University of Minnesota
St. Paul, MN 55108-6028
Voice: 612-625-8145
FAX: 612-625-2208
Email: russelle@soils.umn.edu

While on the subject of TDR, has one out there had any experience with TDR
and measuring soil moisture content on organic soils. I am by no means a
soil scientist but am interested in soil moisture near the soil surface
and its effect upon weed seed germination and the subsequent impact of
weed competition on onion yields. The muck (organic soil) is derived from
a marsh which was drained around 40 years ago and the soil depth is
approximately 8 ft in the location where I work. The plow zone is well
mineralized. I would appreciate any comments on the matter. Thanks.

Rodger Tschanz
Horticulture Department
University of Guelph
Guelph,Ontario,Canada
N1G 2W1
e-mail address:RTSCHANZ@uoguelph.ca
fax number:(519)767-0755

Thanks for the explanation. It helps. I have been uncomfortable about
participating, though, because I am coming from a hobby gardener
perspective (I heard about this list form a w n a wogardening
discussion group. We have questions about drainage in clay soils, pH,
particle size distribution, the nature of clays, and generally issues
dealing with the effects of soils on plant growth. I can assure you that
this is a big issue with many folks and could be significant on soils-l,
if it is encouraged (by the soil experts in this group actually answering
some questions from time to time).

What do you think about this?

Bill Walsh, in Auburn, AL

Hello out there,
I am writing to introduce myself to the list.
My name is Mark Chladil and I'm a PhD student here at U Tasmania.
I'm studying forest climate using amongst other things a TDR unit
for monitoring theta. I am interested in models of the soil-plant-atmosphere
continuum, especially simple ones! I am hoping this List will be a source
of discussion and information. So, to kick off what is the current feeling about TDR in heavy soils? What can be done to improve TDR performance?
Thanks to Jerome Pier for getting the list going!
Cheers
Mark

This is a test.

Please ignore. Sorry for the use of bandwidth.

On Sat, 4 Dec 1993, Mark Chladil wrote:

> So, to kick off what is the current feeling about TDR in heavy soils?

Dr. Keith Cassel, NCSU, indicated that he is having problems getting
accurate readings of moisture content in the heavy clay soils here.
The TDR underestimates water content of clay soils.
Bill Hook suggested that
the reason is that the TDR does
not measure "bound water," which he defines as that water with a different
dielectric constant as pure water.

What can be done to improve
TDR performance?

First identify if Hook's theory is correct, then develop an algorithim to
convert TDR measured values to moisture content measured gravimetrically.
Sounds simple, anyway. It might take a lifetime.

> Thanks to Jerome Pier for getting the
list going!

I second that.

gail

UNSUBSCRIBE SOILS-l mlehman@uclink

This may be of interest to the list.
Tom Hodges---------- Forwarded message ----------
Date: Mon, 6 Dec 1993 12:34:59 -0500 (EST)
From: Gabriel Hegyes <ghegyes@nalusda.gov>
To: SANET-mg <sanet-mg@ces.ncsu.edu>
Subject: Peer Reviewers for NRI's Ag Systems Program (fwd)

---------- Text of forwarded message ----------
Date: Mon, 6 Dec 1993 11:27:00 EST
From: Peter Johnson 202-401-1896 <JOHNSON@a1.darth.esusda.gov>
To: irm@ag.srnr.Arizona.EDU
Subject: Peer Reviewers for NRI's Ag Systems Program

The USDA National Research Initiative Competitive Grants Program is seeking
the names of researchers to be ad hoc reviewers and/or panelists for its
new "Agricultural Systems" program. Ad hoc reviewers would be sent no more
than 2 or 3 proposals to evaluate between April and June of 1994.
Responses can be e-mailed to: Dr. Peter J. Johnson
Johnson@CSRS.ESUSDA.GOV
A follow-up questionnaire will be mailed to each respondent.
Information on proposal submission can also be solicited. The submission
deadline is Feb. 22, 1994 . Thank you.

>
>On Sat, 4 Dec 1993, Mark Chladil wrote:
>
>> So, to kick off what is the current feeling about TDR in heavy soils?
>
>Dr. Keith Cassel, NCSU, indicated that he is having problems getting
>accurate readings of moisture content in the heavy clay soils here.
>The TDR underestimates water content of clay soils.
>Bill Hook suggested that
>the reason is that the TDR does
>not measure "bound water," which he defines as that water with a different
>dielectric constant as pure water.
>
>What can be done to improve
>TDR performance?
>
>First identify if Hook's theory is correct, then develop an algorithim to
>convert TDR measured values to moisture content measured gravimetrically.
> Sounds simple, anyway. It might take a lifetime.
>
>> Thanks to Jerome Pier for getting the
>list going!
>
>I second that.
>
>gail
>
>
>
>
The measurement of water content in clay soils using TDR has recently
been in my mind also. I am Dennis Timlin, a soil scientist with the
Systems Research Lab in Beltsville, MD -USDA-ARS. We are interested
in water uptake by soybeans and I have been making measurements
with TDR. We have also been working on a method to obtain the apparent
dielectric constant from wave traces by simulating the wave trace
and finding the best fit parameters, i.e., the dielectric constants and
impedences in this case. We have also been using soil with high
clay content and I noticed that the calibration curve deviated
significantly from the more common relationship as reported by Clark Topp,
mainly at high water contents. Others I have talked to noted similar
relationships for clay soils. I had some interesting discussions about
this at the recent agronomy meetings, especially with Ray Allmaras. It may have
less to do with bound water than with soil structure and suspension of colloids in
the soil water. The dielectric constant is related to volumetric water content
which is a function of structure and aggregation. This suggests that the
reflection of the wave trace is affected by structure. Structure, to
some extent, is also a function of the shape of the aggregates. Now,
a dielectric model has been used to determine the thermal conductivity
of soils. The shape of the soil particles has some impact on the
thermal conductivity. This suggests that the shape of the soil particles
could also have an effect on the propagation of the electric pulse
in the wave guides. The presence of colloids could explain why the effect
is more pronounced at high water contents. I am still ignorant about
much of this but it does seem to make sense. It seems to me that, if the
cause was bound water, then the effect would be more pronounced at
low water contents where there is relatively more bound water. Anyway,
it seems that TDR could be used to study soil structure. I would be
interested in hearing any other opinions on this.

------------------------------------------------
Dennis Timlin
USDA-ARS Systems Research Lab
Beltsville, MD 20705
301-504-6255
DTimlin@ASRR.ARSUSDA.GOV

I have been reading with interest the discussions on TDR readings in clay soils.
What Ray Allmaras discussed about clay colloids and structure is possible (I
think) and is logical. I have been using an automated TDR system on sand soils
from Florida and clay soils from Missouri. The Missouri soils have a
significant swelling capacity due to the presence of montmorillonite and there-
fore, have a high porosity. Thus far, I have had good agreement between
what Topp discussed and have had basically minimum deviation. However, while
investigating soils in the Southeast in Georgia and other Piedmont soils, we
ran into the same problem you are having. These soils are easily dispersible
however, they also have large amounts of iron and aluminum sesquioxides. Also,
while the Missouri soils are relatively easily dispersible, I naturally accounted
the deviation in TDR readings to the presence of the metal sesquioxides. I'll
have to go back and check my data, but I believe it could be both properties i.
e., 1) colloidal and therefore, structurally related and 2) the presence of
metal sesquioxides and there adverse effects on moisture measurements with other
instruments such as neutron probes (which is well documented). I would be
interested in knowing if Dr. Timlin's soils have any metal components present?
Let's hear some other ideas.

Jim Tindall

I have been reading with interest the discussion on readings from TDR probes
in clay soils. What Ray Allmaras discussed with Dr. Timlin makes sense and
could well be a problem. I have been reading clay soils from Missouri
which have a high content of montmorillonite and therefore, a high swelling
capacity and also sand soils in Florida. Thus far, I encountered no problems
in deviation from what Topp proposed. However, on southern Piedmont soils
from Georgia, we have had many problems in obtaining adequate water content.
These soils are have large concentrations of iron and aluminum sesquioxides
which have been well known to intefere with readings from neutron probes.
Also, they are easily dispersible. It seems that both dispersibility and
therefore structure as well as metal components in soils could interfere
(sometimes) with good TDR measurments. I would be interested in knowing
if the clay soils Dr. Timlin is working on has any metal ions, sesquioxides,
etc. present?

Jim Tindall.

On Tue, 7 Dec 1993 dtimlin@asrr.arsusda.gov wrote:

>
> >
> this at the recent agronomy meetings, especially with Ray Allmaras. It may have
> less to do with
bound water than with soil structure and suspension of colloids in
> the soil water. The dielectric constant
is related to volumetric water content
> which is a function of structure and aggregation.

I'm not sure I follow this argument. The dielectric constant is a
constant (81 for water), so is not related to water content. The
constant will be 81 whether the water content is .4 or .1.

>This suggests that the
> reflection of the wave trace is affected by structure. Structure, to
> some extent, is also a function of the shape of the aggregates.

Here again, I'm not sure what suggests that the reflection of the wave
trace is affected by structure or the shape of the aggregates. I
suspect that there are underestimations of water content in massive
clays as well as strongly-aggregated ones, and that there is every bit
as much of a problem in wet montmorillonites, which swell and become
massive-like in situ, as there is in non-swelling soils.

Now,
> a dielectric model has been used to determine the thermal conductivity
> of soils. The shape of the soil particles has some impact on the
> thermal conductivity. This suggests that the shape of the soil particles
> could also have an effect on the propagation of the electric pulse
> in the wave guides. The presence of colloids could explain why the effect
> is more pronounced at high water contents.

WHy colloids? Also, shapes of soil particles and soil structure are two
different concepts, so even if the TDR measurements are affected by the
shape of soil particles, I don't see how it could be used to measure soil
structure.

gail

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Date: Mon, 6 Dec 1993 13:37:46 -0600
Message-Id: <Pine.3.05.9312061337.B13807-a100000@essnvd5.arrc.ncsu.edu>
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From: Gail Olson <gail@essnvd5.arrc.ncsu.edu>
To: Multiple recipients of list <soils-l@unl.edu>
Subject: Re: introduction



On Sat, 4 Dec 1993, Mark Chladil wrote:

> So, to kick off what is the current feeling about TDR in heavy soils?

Dr. Keith Cassel, NCSU, indicated that he is having problems getting
accurate readings of moisture content in the heavy clay soils here.
The TDR underestimates water content of clay soils.
Bill Hook suggested that
the reason is that the TDR does
not measure "bound water," which he defines as that water with a different
dielectric constant as pure water.

What can be done to improve
TDR performance?

First identify if Hook's theory is correct, then develop an algorithim to
convert TDR measured values to moisture content measured gravimetrically.
Sounds simple, anyway. It might take a lifetime.

> Thanks to Jerome Pier for getting the
list going!

I second that.

gail

End of returned message

Start of returned message

Date: Tue, 7 Dec 1993 16:46:42 -0600
Message-Id: <199312072203.WAA05134@servrcolkr.cr.usgs.gov>
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From: jtindall@servrcolkr.cr.usgs.gov (Jim Tindall)
To: Multiple recipients of list <soils-l@unl.edu>
Subject: TDR readings in clay soils

I have been reading with interest the discussion on readings from TDR probes
in clay soils. What Ray Allmaras discussed with Dr. Timlin makes sense and
could well be a problem. I have been reading clay soils from Missouri
which have a high content of montmorillonite and therefore, a high swelling
capacity and also sand soils in Florida. Thus far, I encountered no problems
in deviation from what Topp proposed. However, on southern Piedmont soils
from Georgia, we have had many problems in obtaining adequate water content.
These soils are have large concentrations of iron and aluminum sesquioxides
which have been well known to intefere with readings from neutron probes.
Also, they are easily dispersible. It seems that both dispersibility and
therefore structure as well as metal components in soils could interfere
(sometimes) with good TDR measurments. I would be interested in knowing
if the clay soils Dr. Timlin is working on has any metal ions, sesquioxides,
etc. present?

Jim Tindall.

End of returned message

Start of returned message

Date: Tue, 7 Dec 1993 15:19:47 -0600
Message-Id: <Chameleon.931207152211.dennis@soilphys.arsusda.gov>
Originator: soils-l@unl.edu
Errors-To: jp@unlinfo.unl.edu
Reply-To: <soils-l@unl.edu>
Sender: soils-l@unl.edu
Version: 5.5 -- Copyright (c) 1991/92, Anastasios Kotsikonas
From: dtimlin@asrr.arsusda.gov
To: Multiple recipients of list <soils-l@unl.edu>
Subject: Re: introduction


>
>On Sat, 4 Dec 1993, Mark Chladil wrote:
>
>> So, to kick off what is the current feeling about TDR in heavy soils?
>
>Dr. Keith Cassel, NCSU, indicated that he is having problems getting
>accurate readings of moisture content in the heavy clay soils here.
>The TDR underestimates water content of clay soils.
>Bill Hook suggested that
>the reason is that the TDR does
>not measure "bound water," which he defines as that water with a different
>dielectric constant as pure water.
>
>What can be done to improve
>TDR performance?
>
>First identify if Hook's theory is correct, then develop an algorithim to
>convert TDR measured values to moisture content measured gravimetrically.
> Sounds simple, anyway. It might take a lifetime.
>
>> Thanks to Jerome Pier for getting the
>list going!
>
>I second that.
>
>gail
>
>
>
>
The measurement of water content in clay soils using TDR has recently
been in my mind also. I am Dennis Timlin, a soil scientist with the
Systems Research Lab in Beltsville, MD -USDA-ARS. We are interested
in water uptake by soybeans and I have been making measurements
with TDR. We have also been working on a method to obtain the apparent
dielectric constant from wave traces by simulating the wave trace
and finding the best fit parameters, i.e., the dielectric constants and
impedences in this case. We have also been using soil with high
clay content and I noticed that the calibration curve deviated
significantly from the more common relationship as reported by Clark Topp,
mainly at high water contents. Others I have talked to noted similar
relationships for clay soils. I had some interesting discussions about
this at the recent agronomy meetings, especially with Ray Allmaras. It may have
less to do with bound water than with soil structure and suspension of colloids in
the soil water. The dielectric constant is related to volumetric water content
which is a function of structure and aggregation. This suggests that the
reflection of the wave trace is affected by structure. Structure, to
some extent, is also a function of the shape of the aggregates. Now,
a dielectric model has been used to determine the thermal conductivity
of soils. The shape of the soil particles has some impact on the
thermal conductivity. This suggests that the shape of the soil particles
could also have an effect on the propagation of the electric pulse
in the wave guides. The presence of colloids could explain why the effect
is more pronounced at high water contents. I am still ignorant about
much of this but it does seem to make sense. It seems to me that, if the
cause was bound water, then the effect would be more pronounced at
low water contents where there is relatively more bound water. Anyway,
it seems that TDR could be used to study soil structure. I would be
interested in hearing any other opinions on this.



------------------------------------------------
Dennis Timlin
USDA-ARS Systems Research Lab
Beltsville, MD 20705
301-504-6255
DTimlin@ASRR.ARSUSDA.GOV

End of returned message

>Subject: Re: introduction
>
>
>
>On Tue, 7 Dec 1993 dtimlin@asrr.arsusda.gov wrote:
>
>>
>> >
>> this at the recent agronomy meetings, especially with Ray Allmaras. It may
have
>> less to do with
>bound water than with soil structure and suspension of colloids in
>> the soil water. The dielectric constant
>is related to volumetric water content
>> which is a function of structure and aggregation.
>
>I'm not sure I follow this argument. The dielectric constant is a
>constant (81 for water), so is not related to water content. The
>constant will be 81 whether the water content is .4 or .1.
>

I changed the subject to TDR in clay soils as done by Dr. Tindall
to provide a better description.

The term 'dielectric constant' roughly refers to how easily
an electric field can pass through a material. Water, which has
a high dielectric constant 'impedes' the passage of an electric
pulse relative to air which allows the electric pulse to pass at
close to it's initial velocity. The TDR instrument measures the velocity of
an electric pulse moving through bare wires that are embedded in
either soil or other insulating material as is around a coaxial
cable. The velocity is measured from the time it takes for the
pulse to return to the registering instrument after being
reflected from the end of the wires or rods. Remember that when you
insert a TDR probe (two or more bare metalic rods with a handle
connected to a coaxial cable) into the soil you are measuring an
average of the dielectric constants of mineral matter, water,
air, and whatever else is there. Yes, the dielectric constant of
water is about 81, which is very high. The constant for air is
1.0 (by definition) and about 4 for quartz. The dielectric constant
for the mixture, therefore, depends on the relative amounts of each
component. Since water has a much higher dielectric constant than
air the dielectric constant of the mixture will vary with the water
content.

>>This suggests that the
>> reflection of the wave trace is affected by structure. Structure, to
>> some extent, is also a function of the shape of the aggregates.
>
>Here again, I'm not sure what suggests that the reflection of the wave
>trace is affected by structure or the shape of the aggregates. I
>suspect that there are underestimations of water content in massive
>clays as well as strongly-aggregated ones, and that there is every bit
>as much of a problem in wet montmorillonites, which swell and become
>massive-like in situ, as there is in non-swelling soils.
>

I don't know enough about this yet to give you a good
answer. However, my feeling is that electric charges are
distributed over the surface of a material and the internal
surface area of a soil is related to structure.

> Now,
>> a dielectric model has been used to determine the thermal conductivity
>> of soils. The shape of the soil particles has some impact on the
>> thermal conductivity. This suggests that the shape of the soil particles
>> could also have an effect on the propagation of the electric pulse
>> in the wave guides. The presence of colloids could explain why the effect
>> is more pronounced at high water contents.
>
>WHy colloids? Also, shapes of soil particles and soil structure are two
>different concepts, so even if the TDR measurements are affected by the
>shape of soil particles, I don't see how it could be used to measure soil
>structure.
>
>gail
>

You have a good point. The important thing I see in your
question is that I really don't have a good idea in mind as to
how I'm going to define structure in terms of using a TDR to
measure it. It's something I'll have to think about as I
consider this problem. I can say something here. One is that the
difference between soil particles and soil aggregates is
sometimes only a matter of scale. I would suppose that the
measurement would give me some idea of the surface area of the
soil pore structure. This would be a function of how the soil is
aggregated. I use the example of colloids to show that there
may be more to clay soils and TDR measurements than only bound
water. The presence of colloids, however, may only confound
measurements made for some kind of structure.

Actually, I shouldn't disregard the effect of bound water
altogether. But I think it's more a function of the geometry of
the surfaces on which the water is adsorbed and not the bound
water itself.

These were good questions Gail, Thank you.

Dennis

------------------------------------------------
Dennis Timlin
USDA-ARS Systems Research Lab
Beltsville, MD 20705
301-504-6255
DTimlin@ASRR.ARSUSDA.GOV

In Jim Tindalls posting...
>However, while
>investigating soils in the Southeast in Georgia and other Piedmont soils, we
>ran into the same problem you are having. These soils are easily dispersible
>however, they also have large amounts of iron and aluminum sesquioxides. Also,
>while the Missouri soils are relatively easily dispersible, I naturally accounted
>the deviation in TDR readings to the presence of the metal sesquioxides. I'll
>have to go back and check my data, but I believe it could be both properties i.
>e., 1) colloidal and therefore, structurally related and 2) the presence of
>metal sesquioxides and there adverse effects on moisture measurements with other
>instruments such as neutron probes (which is well documented). I would be
>interested in knowing if Dr. Timlin's soils have any metal components present?
>Let's hear some other ideas.
>
>Jim Tindall
>

That's interesting, I haven't considered it and I'm not sure
what the metal components would be in the soil I have used. But I
think that the effect of the dielectric constants of the metal oxides
would not be large at high water contents because the dielectric
constant of water would dominate. Do you think it may have something
to do with the surface area of the clay particles?

Dennis

------------------------------------------------
Dennis Timlin
USDA-ARS Systems Research Lab
Beltsville, MD 20705
301-504-6255
DTimlin@ASRR.ARSUSDA.GOV

I'm a professor in Physical Geography, Gothenburg university on the
Swedish west coast. Although I'm not a soil specialist I decided to
join the soils-l since there are some graduate students at the Dept.
working in this field. Since the list started it has been a pleasure
to follow the different introductions popping up although most of them
during night-time here. My interests are very diverse covering Global
change, Marine aerosols deposition and distribution, Wetlands
(including peat and carbon cycle), Saharan dust events etc. The
closest connexion to soils-l concerns the following theme (which
have also been presented for subscribers on the geomorphlist):

"An index for classification of mineral soils based on sorting, and
the shape and lustre of quartz grains"

About 15 years ago me and one of my colleagues investigated the
process of dune sand eolization in Neviot, Sinai. We tried to use the
old classification system for quartz grains invented by A. Cailleux
but we found it too coarse to use for small changes in grain
population characterization.

A modification of the method lead us to start investigate other
mineral soils but dune sand e.g. weathering material, beach sands,
tills etc. Finally with more than 600 different, world-wide
environments studied we have found the method suitable to investigate
mineral soil genesis.

The method is simple, and the results are presented as a three-gouped
(3-D) six-digit index, including sorting and the lustre/shape of the
grains. For the analysis we use a simple light-microscope
(polarization). Appr. 200 grains are studied and classified. Some
calculations leas us to the result.

The amount of raw soil used is 50 g or more but we can do with appr.
1 g of the 0.25-0.5 mm fraction, which is used for microscope
studies. Sorting could be calculated knowing the total dry weight of
the sample and the distribution of weights on different sieves.

It's our hope that these studies might lead to an "Atlas of mineral
soils". The purpose of this appeal is to increase the number of
samples and different environments, and we know that most people
working in soil sciences etc. are travelleres. If you decide to
support this project please send any mineral soil sample giving the
sample site (pref. with coordinates and a small map), sampling
environment (dune sand, loess, beach, moraine, esker, weathering,
kaoline etc. etc.) and any other information which might be of value
(recent processes, surrounding rocks etc.). Every supporter to this
project will be mentioned in a coming paper. In the future it's our
hope that the Internet could be used for the distribution of indicies
(the complete method, with calculations will be distributed as soon
as our first paper is out), hence finally forming a world wide
mineral soil network and hopefully a printed atlas.

Please send your samples or any ideas concering this to:

Lars Franzen
Dept. of Physical Geography
Reutersgatan 2C
s-413 20 Gothenburg
Sweden

Tel. ++ 46-31-7731958
Fax. ++ 46-31-7731986
Int.net. LARS@gig.gu.se

> pulse relative to air which allows the electric pulse to pass at
> close to it's initial velocity. The TDR instrument measures the velocity of
> an electric pulse moving through bare wires that are embedded in
> either soil or other insulating material as is around a coaxial
> cable.

The TDR only measures time, not velocity, and the water
content is obtained from the (assumed) linear relationship between T/To and
volumetric water content. The slope of the line is roughly equal to the
inverse of the dielectric constant. Hook says that this relationship
holds when there is not bound water (of any consequence) but that the
relationship between water content and T/To is a non-linear, non-differntiable
function. He shows the relationship as a curve rising steeply then
leveling off, and says that the TDR underestimates water content in the
mid-range moreso than the higher range (of water content).

The main point of interest (I thought) was his definition of bound water:
that which doesn't have the same dielectric constant as pure water. If the
adsorbed water has a higher dielectric constant, the slope of the line
(with x being T/To and y being water content) would be steeper than that
of the slope used in TDR estimates; the underestimation of water content
could be explained. But if water contents at the high range are being
accurately predicted by TDR while mid range values are underestimated,
then the relationship is probably non-linear and more complex.

>
> ...I really don't have a good idea in mind as to
> how I'm going to define structure in terms of using a TDR to
> measure it.

I don't see it as being feasible, however, it would be interesting to
know (for starters) if the TDR measured water content differently for
oriented vs. non-oriented clays of the same type.

It's something I'll have to
think about
as I > consider this problem. I can say something here. One is that the
> difference between soil particles and soil aggregates is
> sometimes only a matter of scale. I would suppose that the
> measurement would give me some idea of the surface area of the
> soil pore structure. This would be a function of how the soil is
> aggregated.

THis is interesting. Evidently, by underestimating water content in the
clay soils, the TDR does indeed detect water in micropores differently.

the example of colloids to show that
there > may be more to clay soils and TDR measurements than only bound
> water. The presence of colloids, however, may only confound
> measurements made for some kind of structure.

Then again, it may just be a bound water problem (or should I say
"challenge" or "opportunity")! Also, some folks are
using TDR to measure electrical conductivity. I don't know what kind of
success they are having with that, but I would think that the concept is
very similar to that of the bound water, and it would be interesting to
hear from them.
>
>
Actually, I shouldn't disregard the effect of bound
water > altogether. But I think it's more a function of the geometry of
> the surfaces on which the water is adsorbed and not the bound
> water itself.
>
Could be.

g

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Start of returned message

Date: Thu, 9 Dec 1993 05:56:13 -0600
Message-Id: <MAILQUEUE-99.931209125222.480@gig.gu.se>
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From: LARS@gig.gu.se
To: Multiple recipients of list <soils-l@unl.edu>
Subject: Lars Franzen - Introduction and Appeal


I'm a professor in Physical Geography, Gothenburg university on the
Swedish west coast. Although I'm not a soil specialist I decided to
join the soils-l since there are some graduate students at the Dept.
working in this field. Since the list started it has been a pleasure
to follow the different introductions popping up although most of them
during night-time here. My interests are very diverse covering Global
change, Marine aerosols deposition and distribution, Wetlands
(including peat and carbon cycle), Saharan dust events etc. The
closest connexion to soils-l concerns the following theme (which
have also been presented for subscribers on the geomorphlist):

"An index for classification of mineral soils based on sorting, and
the shape and lustre of quartz grains"

About 15 years ago me and one of my colleagues investigated the
process of dune sand eolization in Neviot, Sinai. We tried to use the
old classification system for quartz grains invented by A. Cailleux
but we found it too coarse to use for small changes in grain
population characterization.

A modification of the method lead us to start investigate other
mineral soils but dune sand e.g. weathering material, beach sands,
tills etc. Finally with more than 600 different, world-wide
environments studied we have found the method suitable to investigate
mineral soil genesis.

The method is simple, and the results are presented as a three-gouped
(3-D) six-digit index, including sorting and the lustre/shape of the
grains. For the analysis we use a simple light-microscope
(polarization). Appr. 200 grains are studied and classified. Some
calculations leas us to the result.

The amount of raw soil used is 50 g or more but we can do with appr.
1 g of the 0.25-0.5 mm fraction, which is used for microscope
studies. Sorting could be calculated knowing the total dry weight of
the sample and the distribution of weights on different sieves.

It's our hope that these studies might lead to an "Atlas of mineral
soils". The purpose of this appeal is to increase the number of
samples and different environments, and we know that most people
working in soil sciences etc. are travelleres. If you decide to
support this project please send any mineral soil sample giving the
sample site (pref. with coordinates and a small map), sampling
environment (dune sand, loess, beach, moraine, esker, weathering,
kaoline etc. etc.) and any other information which might be of value
(recent processes, surrounding rocks etc.). Every supporter to this
project will be mentioned in a coming paper. In the future it's our
hope that the Internet could be used for the distribution of indicies
(the complete method, with calculations will be distributed as soon
as our first paper is out), hence finally forming a world wide
mineral soil network and hopefully a printed atlas.

Please send your samples or any ideas concering this to:

Lars Franzen
Dept. of Physical Geography
Reutersgatan 2C
s-413 20 Gothenburg
Sweden

Tel. ++ 46-31-7731958
Fax. ++ 46-31-7731986
Int.net. LARS@gig.gu.se

End of returned message

Start of returned message

Date: Wed, 8 Dec 1993 16:41:16 -0600
Message-Id: <Chameleon.931208173729.dennis@soilphys.arsusda.gov>
Originator: soils-l@unl.edu
Errors-To: jp@unlinfo.unl.edu
Reply-To: <soils-l@unl.edu>
Sender: soils-l@unl.edu
Version: 5.5 -- Copyright (c) 1991/92, Anastasios Kotsikonas
From: dtimlin@asrr.arsusda.gov
To: Multiple recipients of list <soils-l@unl.edu>
Subject: RE: TDR readings in clay soils (was RE: Introd)

>Subject: Re: introduction
>
>
>
>On Tue, 7 Dec 1993 dtimlin@asrr.arsusda.gov wrote:
>
>>
>> >
>> this at the recent agronomy meetings, especially with Ray Allmaras. It may
have
>> less to do with
>bound water than with soil structure and suspension of colloids in
>> the soil water. The dielectric constant
>is related to volumetric water content
>> which is a function of structure and aggregation.
>
>I'm not sure I follow this argument. The dielectric constant is a
>constant (81 for water), so is not related to water content. The
>constant will be 81 whether the water content is .4 or .1.
>

I changed the subject to TDR in clay soils as done by Dr. Tindall
to provide a better description.

The term 'dielectric constant' roughly refers to how easily
an electric field can pass through a material. Water, which has
a high dielectric constant 'impedes' the passage of an electric
pulse relative to air which allows the electric pulse to pass at
close to it's initial velocity. The TDR instrument measures the velocity of
an electric pulse moving through bare wires that are embedded in
either soil or other insulating material as is around a coaxial
cable. The velocity is measured from the time it takes for the
pulse to return to the registering instrument after being
reflected from the end of the wires or rods. Remember that when you
insert a TDR probe (two or more bare metalic rods with a handle
connected to a coaxial cable) into the soil you are measuring an
average of the dielectric constants of mineral matter, water,
air, and whatever else is there. Yes, the dielectric constant of
water is about 81, which is very high. The constant for air is
1.0 (by definition) and about 4 for quartz. The dielectric constant
for the mixture, therefore, depends on the relative amounts of each
component. Since water has a much higher dielectric constant than
air the dielectric constant of the mixture will vary with the water
content.

>>This suggests that the
>> reflection of the wave trace is affected by structure. Structure, to
>> some extent, is also a function of the shape of the aggregates.
>
>Here again, I'm not sure what suggests that the reflection of the wave
>trace is affected by structure or the shape of the aggregates. I
>suspect that there are underestimations of water content in massive
>clays as well as strongly-aggregated ones, and that there is every bit
>as much of a problem in wet montmorillonites, which swell and become
>massive-like in situ, as there is in non-swelling soils.
>

I don't know enough about this yet to give you a good
answer. However, my feeling is that electric charges are
distributed over the surface of a material and the internal
surface area of a soil is related to structure.

> Now,
>> a dielectric model has been used to determine the thermal conductivity
>> of soils. The shape of the soil particles has some impact on the
>> thermal conductivity. This suggests that the shape of the soil particles
>> could also have an effect on the propagation of the electric pulse
>> in the wave guides. The presence of colloids could explain why the effect
>> is more pronounced at high water contents.
>
>WHy colloids? Also, shapes of soil particles and soil structure are two
>different concepts, so even if the TDR measurements are affected by the
>shape of soil particles, I don't see how it could be used to measure soil
>structure.
>
>gail
>

You have a good point. The important thing I see in your
question is that I really don't have a good idea in mind as to
how I'm going to define structure in terms of using a TDR to
measure it. It's something I'll have to think about as I
consider this problem. I can say something here. One is that the
difference between soil particles and soil aggregates is
sometimes only a matter of scale. I would suppose that the
measurement would give me some idea of the surface area of the
soil pore structure. This would be a function of how the soil is
aggregated. I use the example of colloids to show that there
may be more to clay soils and TDR measurements than only bound
water. The presence of colloids, however, may only confound
measurements made for some kind of structure.

Actually, I shouldn't disregard the effect of bound water
altogether. But I think it's more a function of the geometry of
the surfaces on which the water is adsorbed and not the bound
water itself.


These were good questions Gail, Thank you.



Dennis

------------------------------------------------
Dennis Timlin
USDA-ARS Systems Research Lab
Beltsville, MD 20705
301-504-6255
DTimlin@ASRR.ARSUSDA.GOV

End of returned message

Start of returned message

Date: Wed, 8 Dec 1993 16:44:47 -0600
Message-Id: <Chameleon.931208174024.dennis@soilphys.arsusda.gov>
Originator: soils-l@unl.edu
Errors-To: jp@unlinfo.unl.edu
Reply-To: <soils-l@unl.edu>
Sender: soils-l@unl.edu
Version: 5.5 -- Copyright (c) 1991/92, Anastasios Kotsikonas
From: dtimlin@asrr.arsusda.gov
To: Multiple recipients of list <soils-l@unl.edu>
Subject: RE: TDR readings in clay soils

In Jim Tindalls posting...
>However, while
>investigating soils in the Southeast in Georgia and other Piedmont soils, we
>ran into the same problem you are having. These soils are easily dispersible
>however, they also have large amounts of iron and aluminum sesquioxides. Also,
>while the Missouri soils are relatively easily dispersible, I naturally accounted
>the deviation in TDR readings to the presence of the metal sesquioxides. I'll
>have to go back and check my data, but I believe it could be both properties i.
>e., 1) colloidal and therefore, structurally related and 2) the presence of
>metal sesquioxides and there adverse effects on moisture measurements with other
>instruments such as neutron probes (which is well documented). I would be
>interested in knowing if Dr. Timlin's soils have any metal components present?
>Let's hear some other ideas.
>
>Jim Tindall
>

That's interesting, I haven't considered it and I'm not sure
what the metal components would be in the soil I have used. But I
think that the effect of the dielectric constants of the metal oxides
would not be large at high water contents because the dielectric
constant of water would dominate. Do you think it may have something
to do with the surface area of the clay particles?


Dennis



------------------------------------------------
Dennis Timlin
USDA-ARS Systems Research Lab
Beltsville, MD 20705
301-504-6255
DTimlin@ASRR.ARSUSDA.GOV

End of returned message

Start of returned message

Date: Wed, 8 Dec 1993 07:47:49 -0600
Message-Id: <Pine.3.05.9312080842.A20619-b100000@essnvd5.arrc.ncsu.edu>
Originator: soils-l@unl.edu
Errors-To: jp@unlinfo.unl.edu
Reply-To: <soils-l@unl.edu>
Sender: soils-l@unl.edu
Version: 5.5 -- Copyright (c) 1991/92, Anastasios Kotsikonas
From: Gail Olson <gail@essnvd5.arrc.ncsu.edu>
To: Multiple recipients of list <soils-l@unl.edu>
Subject: Re: introduction



On Tue, 7 Dec 1993 dtimlin@asrr.arsusda.gov wrote:

>
> >
> this at the recent agronomy meetings, especially with Ray Allmaras. It may have
> less to do with
bound water than with soil structure and suspension of colloids in
> the soil water. The dielectric constant
is related to volumetric water content
> which is a function of structure and aggregation.

I'm not sure I follow this argument. The dielectric constant is a
constant (81 for water), so is not related to water content. The
constant will be 81 whether the water content is .4 or .1.

>This suggests that the
> reflection of the wave trace is affected by structure. Structure, to
> some extent, is also a function of the shape of the aggregates.

Here again, I'm not sure what suggests that the reflection of the wave
trace is affected by structure or the shape of the aggregates. I
suspect that there are underestimations of water content in massive
clays as well as strongly-aggregated ones, and that there is every bit
as much of a problem in wet montmorillonites, which swell and become
massive-like in situ, as there is in non-swelling soils.

Now,
> a dielectric model has been used to determine the thermal conductivity
> of soils. The shape of the soil particles has some impact on the
> thermal conductivity. This suggests that the shape of the soil particles
> could also have an effect on the propagation of the electric pulse
> in the wave guides. The presence of colloids could explain why the effect
> is more pronounced at high water contents.

WHy colloids? Also, shapes of soil particles and soil structure are two
different concepts, so even if the TDR measurements are affected by the
shape of soil particles, I don't see how it could be used to measure soil
structure.

gail

End of returned message

Start of returned message

Date: Tue, 7 Dec 1993 16:45:22 -0600
Message-Id: <199312072151.VAA05107@servrcolkr.cr.usgs.gov>
Originator: soils-l@unl.edu
Errors-To: jp@unlinfo.unl.edu
Reply-To: <soils-l@unl.edu>
Sender: soils-l@unl.edu
Version: 5.5 -- Copyright (c) 1991/92, Anastasios Kotsikonas
From: jtindall@servrcolkr.cr.usgs.gov (Jim Tindall)
To: Multiple recipients of list <soils-l@unl.edu>
Subject: TDR readings in clay soils

I have been reading with interest the discussions on TDR readings in clay soils.
What Ray Allmaras discussed about clay colloids and structure is possible (I
think) and is logical. I have been using an automated TDR system on sand soils
from Florida and clay soils from Missouri. The Missouri soils have a
significant swelling capacity due to the presence of montmorillonite and there-
fore, have a high porosity. Thus far, I have had good agreement between
what Topp discussed and have had basically minimum deviation. However, while
investigating soils in the Southeast in Georgia and other Piedmont soils, we
ran into the same problem you are having. These soils are easily dispersible
however, they also have large amounts of iron and aluminum sesquioxides. Also,
while the Missouri soils are relatively easily dispersible, I naturally accounted
the deviation in TDR readings to the presence of the metal sesquioxides. I'll
have to go back and check my data, but I believe it could be both properties i.
e., 1) colloidal and therefore, structurally related and 2) the presence of
metal sesquioxides and there adverse effects on moisture measurements with other
instruments such as neutron probes (which is well documented). I would be
interested in knowing if Dr. Timlin's soils have any metal components present?
Let's hear some other ideas.

Jim Tindall

End of returned message

Start of returned message

Date: Thu, 9 Dec 1993 08:47:13 -0600
Message-Id: <Pine.3.05.9312090925.C25012-c100000@essnvd5.arrc.ncsu.edu>
Originator: soils-l@unl.edu
Errors-To: jp@unlinfo.unl.edu
Reply-To: <soils-l@unl.edu>
Sender: soils-l@unl.edu
Version: 5.5 -- Copyright (c) 1991/92, Anastasios Kotsikonas
From: Gail Olson <gail@essnvd5.arrc.ncsu.edu>
To: Multiple recipients of list <soils-l@unl.edu>
Subject: RE: TDR readings in clay soils (was RE: Introd)

> pulse relative to air which allows the electric pulse to pass at
> close to it's initial velocity. The TDR instrument measures the velocity of
> an electric pulse moving through bare wires that are embedded in
> either soil or other insulating material as is around a coaxial
> cable.

The TDR only measures time, not velocity, and the water
content is obtained from the (assumed) linear relationship between T/To and
volumetric water content. The slope of the line is roughly equal to the
inverse of the dielectric constant. Hook says that this relationship
holds when there is not bound water (of any consequence) but that the
relationship between water content and T/To is a non-linear, non-differntiable
function. He shows the relationship as a curve rising steeply then
leveling off, and says that the TDR underestimates water content in the
mid-range moreso than the higher range (of water content).

The main point of interest (I thought) was his definition of bound water:
that which doesn't have the same dielectric constant as pure water. If the
adsorbed water has a higher dielectric constant, the slope of the line
(with x being T/To and y being water content) would be steeper than that
of the slope used in TDR estimates; the underestimation of water content
could be explained. But if water contents at the high range are being
accurately predicted by TDR while mid range values are underestimated,
then the relationship is probably non-linear and more complex.

>
> ...I really don't have a good idea in mind as to
> how I'm going to define structure in terms of using a TDR to
> measure it.

I don't see it as being feasible, however, it would be interesting to
know (for starters) if the TDR measured water content differently for
oriented vs. non-oriented clays of the same type.

It's something I'll have to
think about
as I > consider this problem. I can say something here. One is that the
> difference between soil particles and soil aggregates is
> sometimes only a matter of scale. I would suppose that the
> measurement would give me some idea of the surface area of the
> soil pore structure. This would be a function of how the soil is
> aggregated.

THis is interesting. Evidently, by underestimating water content in the
clay soils, the TDR does indeed detect water in micropores differently.

the example of colloids to show that
there > may be more to clay soils and TDR measurements than only bound
> water. The presence of colloids, however, may only confound
> measurements made for some kind of structure.


Then again, it may just be a bound water problem (or should I say
"challenge" or "opportunity")! Also, some folks are
using TDR to measure electrical conductivity. I don't know what kind of
success they are having with that, but I would think that the concept is
very similar to that of the bound water, and it would be interesting to
hear from them.
>
>
Actually, I shouldn't disregard the effect of bound
water > altogether. But I think it's more a function of the geometry of
> the surfaces on which the water is adsorbed and not the bound
> water itself.
>
Could be.

g

End of returned message

*********** AN INVITATION *********
ELECTRONIC CONFERENCE ON INDICATORS OF SUSTAINABILITY

The Sustainable Agriculture and Natural Resource Management
Collaborative Research Support Program (SANREM CRSP) and
INFORUM, an International Forum for the Development of
Sustainable Land Use Systems are inviting anyone interested
the development of physical, biological, social, and
economical indicators of sustainability to participate in an
electronic conference from January 17 to April 15, 1994.

The purpose of the electronic conference is to:

a) develop case studies describing the process followed to
identify potential indicators, evaluate and select appropriate
indicators, and use indicators in different types of
analyses involving tradeoffs between short-term productivity
and long-term sustainability. These case studies will be shared
among conferees and also used as resource materials for a
workshop to be help in Washington D.C. in May, 1994.

b) involve others in planning the May 1994 workshop

Registration for the electronic conference is now open. The
electronic conference room has a bulletin board (BB), a table,
and a file cabinet (FC). The BB and Table are listservers that
will relay posted information to your e-mail box. The FC is set
up to receive longer documents that can be requested on an
individual basis.

The first step is to subscribe to the BB and Table so that you will
receive copies of the notes posted by people registering for the
conference and can participate in the discussion at the Table. To
subscribe send an electronic mail message where the first two line
of text (not the subject line) reads:

SUBSCRIBE INDICATORS BB
SUBSCRIBE INDICATORS TABLE

Send this 2-line message to the following address:

ALMANAC@PARTI.INFORUM.ORG

You should receive a confirmation from the Almanac server. If you
do not receive a confirmation in 48 hours, send an e-mail message
to the address: ALMANAC.TOPIC@PARTI.INFORUM.ORG and your address
will be added manually to the lists.

The next step is to register for the conference. Send an e-mail
message with your name, institution, telephone, fax, e-mail
address, and a few lines describing your particular interest in
sustainability indicators. Send this e-mail message to:

INDICATORS_BB.TOPIC@PARTI.INFORUM.ORG

Note the underline between INDICATORS and BB! The note you send to
this topic will be relayed to everyone who has subscribe to the BB.

Hello soils-l subscribers.. My name is Dr. Bill Fiebig. I work for Rodale
Institute as the Technology Program Coordinator for the DESFIL project in Wash.
D.C. I am an agronomist and work in the area of natural resource management in
Africa. I am developing a data base on the critical variable (biophysical and
socio-economic) associated with the adaption/adoption of regenerative land-use
practices. My question to all of you: What are the critical enabling
conditions which are associated with limited-resources farmers (men and women)
use of regenerative land-use management practices related to soil & water
conservation and soil fertility enhancement?
Tel. (202) 331-1861 Fax. (202) 331-1871 e-mail:
Bill_Fiebig.inbox@parti.inforum.org

On Fri, 10 Dec 1993 BILL_FIEBIG.parti@parti.inforum.org wrote:

> My question to all of you: What are the critical enabling
> conditions which are associated with limited-resources farmers (men and women)
> use of regenerative land-use management practices related to soil & water
> conservation and soil fertility enhancement?
> Tel. (202) 331-1861 Fax. (202) 331-1871 e-mail:
> Bill_Fiebig.inbox@parti.inforum.org

Could you restate this??? Or, define limited-resources farmers (are there
such things as unlimited-resources farmers), critical enabling conditions
(physical, societal, economic), and regenerative land-use management
practices.

--gail

*********** AN INVITATION *********
ELECTRONIC CONFERENCE ON INDICATORS OF SUSTAINABILITY

The Sustainable Agriculture and Natural Resource Management
Collaborative Research Support Program (SANREM CRSP) and
INFORUM, an International Forum for the Development of
Sustainable Land Use Systems are inviting anyone interested
the development of physical, biological, social, and
economical indicators of sustainability to participate in an
electronic conference from January 17 to April 15, 1994.

The purpose of the electronic conference is to:

a) develop case studies describing the process followed to
identify potential indicators, evaluate and select appropriate
indicators, and use indicators in different types of
analyses involving tradeoffs between short-term productivity
and long-term sustainability. These case studies will be shared
among conferees and also used as resource materials for a
workshop to be help in Washington D.C. in May, 1994.

b) involve others in planning the May 1994 workshop

Registration for the electronic conference is now open. The
electronic conference room has a bulletin board (BB), a table,
and a file cabinet (FC). The BB and Table are listservers that
will relay posted information to your e-mail box. The FC is set
up to receive longer documents that can be requested on an
individual basis.

The first step is to subscribe to the BB and Table so that you will
receive copies of the notes posted by people registering for the
conference and can participate in the discussion at the Table. To
subscribe send an electronic mail message where the first two line
of text (not the subject line) reads:

SUBSCRIBE INDICATORS BB
SUBSCRIBE INDICATORS TABLE

Send this 2-line message to the following address:

ALMANAC@PARTI.INFORUM.ORG

You should receive a confirmation from the Almanac server. If you
do not receive a confirmation in 48 hours, send an e-mail message
to the address: ALMANAC.TOPIC@PARTI.INFORUM.ORG and your address
will be added manually to the lists.

The next step is to register for the conference. Send an e-mail
message with your name, institution, telephone, fax, e-mail
address, and a few lines describing your particular interest in
sustainability indicators. Send this e-mail message to:

INDICATORS_BB.TOPIC@PARTI.INFORUM.ORG

Note the underline between INDICATORS and BB! The note you send to
this topic will be relayed to everyone who has subscribe to the BB.

> What are the critical enabling
>conditions which are associated with limited-resources farmers (men and women)
>use of regenerative land-use management practices related to soil & water
>conservation and soil fertility enhancement?
>Tel. (202) 331-1861 Fax. (202) 331-1871 e-mail:
>Bill_Fiebig.inbox@parti.inforum.org

I haven't worked with people with maybe as many cultural differences from
my own as you have working in Africa, but I may be some relevant thoughts.
I am among the "moderately" experienced, and have observed some much better
"helpers," so these are ideas valid only through today. My biggest
"project" is my home town, and it isn't yet my best example of helpfulness.
Also, in today's information explosion age, I think that we are ALL
limited resource producers, no matter what we produce. We are especially
limited in the information about tools and management options that "are
free" and most of these come from between our ears!

In this country and in Mexico I have found that the most important
limitation is one of attitude. All of the people I have worked with want
to succeed in a sustainable way, and seem frustrated because "everything"
seems against such a success. Thus frustration is the limitation, and
giving a sense of direction and decision making that "works" is the first
and most important change to be achieved. The sense of direction is based
on (1) a shared quality of life that is desired -- NOW as much as possible,
and the balance achievable; (2) a way that economically -- not just money
-- is low risk in the long haul; (3) a sense of achieving the above on a
landscape that is pleasant for them to live and work on. A person needs to
know their resources, people, financial, and space (land). This is much
more than a family unit, but must include the family; much more than money
and net worth, but includes those features; and much more than land owned
or leased, but includes those. For example, a community is recognized to
be a powerful resource, shared labor in the community is seen as more than
being helpful to get through a crisis. "Neighboring" is a way to (in spite
of the TV) get double duty out of time -- working to finish a job and
visiting along with it. Experts are most helpful if they "slop the hogs
and milk one of the cows while we talk."

Next, the decision making must be based on flexibility and available
information. We have institutionalized much of the decisions in "research"
and "cost sharing" where generalizations may not fit a particular
operation. In fact, these institutionalized practices tend to produce
tunnel vision in recognizing the options available. The decisions are most
successful when they clearly are from casting a "wide net" for ideas
(neighbors and experts alike help here). Actions need to be evaluated for
effects expected against the goal so as not to undermine the personal
values, economic health, or ecosystem. Tradeoffs and compromises represent
a limitation of options, that is, shortage of information.

And, last but equally important, it is vital that close monitoring of
results be maintained. We say, "Do the best you can in making decisions,
but always assume you are wrong." In that way there is a tight loop
between action and correction when progress toward the goal is not
forthcoming. The top few inches (even 5mm) of soil are often the best
indicator of return to health. Dung beetles can come before earthworms,
litter before humus, and annuals before perennials (as we all know).
Getting the surface of the soil covered is the first order of business, and
"with what" is second order priority. (You folks at Rodale are experts at
these things, and I learn from you.)

Ironically, many "primitive" or "old fashioned" farmers and herdsmen have a
sense of these principles through tradition (values, sustainability) and
intensive trial and error. In these cases much of the effort is to
"validate" what they want to do, and AUGMENT THEIR RESOURCES with
information. It is very important, I believe, that whatever we do that it
not be "what we would do in someone else's shoes" because that is
implicitly contributing to a decision that will be based on different
criteria than "theirs" and much of the decision making is intuitive, and
very personal. This needs to be encouraged, but with a sturcture for using
the objective tools efficiently also. (I guard against such phrases as "you
should ..." or "I would ..." and let "them" get the ideas. I can talk
about processes and how tools affect them, especially the tools that they
already have and money is not a factor. Beneficial insects and such "free"
tools may be better understood by the other person than by me, particularly
when I'm in a new area.)

Helping folks is an art, I believe. If 5% of this is new, I'll be
surprised, but 5% may be helpful. Good Luck.

R. H. (Dick) Richardson
Zoology Dept.
Univ. of Texas
Austin, TX 78712

email: dickr@utxvm.cc.utexas.edu
office: 512-471-4128
home: 512-476-5131
FAX: 512-471-9651

Dear Soils-l and Agmodels-l Subscribers,

I am passing on this information from Dr. Glendon Gee who is in
charge of the Soil Physics Newsletter. Dr. Gee has moved into the
Information age by making the Newsletter accessable thru a
Listserv list. Let's hope that the other divisions of the
Society follow suit. Below is the information which describes the
Newsletter and how to subscribe to the listserv. NOTE: this is
NOT a Soil Physics discussion group. For those who would just
like to receive the Newsletter without subscribing, I have
offered to post the Newsletters on both Soils-l and Agmodels-l as
long as no one objects.

Jerome Pier List Owner
jp@unl.edu

------------------------------Cut----Here------------------------

Welcome to S1-NEWS, the Pacific Northwest Laboratory's
Email Discussion list for
Division S1 of the Soil Science Society of America

Overview

The S1-NEWS group has been set up to provide electronic communication
for the soil physics division (S-1) of the Soil Science Society of
America. This communication link is organized to cover topics of
mutual interest and to act as a supplement to the Agronomy Journal and
other official organs of the SSSA to communicate things of interest to
the S-1 division.

This is an initial attempt to provide an electronic network service to
members of the society interested in soil physics topics. An action
item at the recent S-1 business meeting was for Glendon Gee to
initiate a newsletter that would provide current news to the S-1
members. It was felt that INTERNET could be the vehicle for providing
that service. E-mail addresses were requested at the business meeting
from those who attended.

Since the S-1 business meeting, Bill Jury has taken the initiative to
secure e-mail addresses and circulate them over INTERNET. You should
have received his several messages sent in November. This is the next
step in the process of setting up an electronic newsletter and a rapid
communication link.

In the interim, the S-1 planning committee has been communicating
about activities for the next annual meetings and items that should be
brought up to the SSSA executive board meeting.

Any response on the past annual meetings, notices of upcoming meetings
of interest to S-1 members, or other subjects of general interest will
be welcome. Please send information to the LISTSERV address described
below.

A very simple process for a free "subscription" to the LISTSERV group,
S1-NEWS, is described below.



Messages mailed to S1-NEWS@VOGLNP.PNL.GOV are distributed to all list
subscribers. Please do not send messages longer than about 500 lines;
break long messages up into multiple shorter messages.


Selected LISTSERV Commands

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To get help on LISTSERV commands, send the following e-mail message to
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HELP

To: Soils-l@lun.edu
Subject: Instantaneous Profile Method
>
I have been very successful in using time domain reflectometry and
pressure transducer equipped tensiometors to run the Instantaneous Profile
Method (IPM) in a sandy soil. Advantage of the method is that it is a
in-situ measurement. Disadvantage of the method is that the soil water
pressure (matric pressure) range is very limited. It also takes a long
time to complete a experiment. If you have specific questions, please
contact me at the following e-mail address, or post your questions on this
list server.
>
Wu, Laosheng
Postdoc, Soil Physicist
Soil Science Department
University of Minnesota
Area of Interests: Water and solute transport-experimental and modeling
E-mail:lwu@soils.umn.edu
>

I am interested in measuring organic matter breakdown rate in numerous
soil types, and would like
some information about methods, spatial and temporal variability,
variability associated with soil type (e.g., different textural classes),
or any experience you may have had with this method. I would also
greatly appreciate some good references.

Thanks in advance

gail

Hello everybody!
Gail olson wrote
> I am interested in measuring organic matter breakdown rate in numerous
> soil types, and would like
> some information about methods, spatial and temporal variability,
> variability associated with soil type (e.g., different textural classes),
> or any experience you may have had with this method. I would also
> greatly appreciate some good references.
I'd like to second his request for information very much.
Maybe people who are experts in this field could post some basic information
to the list?
Thanks in advance!
joerg
+--------------------------------+
| Joerg Kaduk |
| MPI for Meteorology |
| Bundesstr. 55 |
| D-20146 Hamburg |
| kaduk@dkrz.d400.de |
+--------------------------------+

Grasslands Mailing Group:

Item of potential interest to students or members of the mailing group.

David

David B. Hannaway
125 Crop Science Building
Department of Crop & Soil Science
Oregon State University
Corvallis, OR 97331-3002
Tel: 503-737-5863
Fax: 503-737-1589
Email: david@oscs.orst.edu
NeXTmail OK!

==============

Begin forwarded message:

Posted-Date: Wed, 29 Dec 93 11:08:12 CST
Received-Date: Wed, 29 Dec 93 07:55:37 -0800
X-Popmail-Charset: English
Date: Wed, 29 Dec 93 11:08:12 CST
From: (Linda Kinkel) <lindak@puccini.crl.umn.edu>
To: sanet-mg@ces.ncsu.edu

Postdoctoral Associate Position--Sustainable Agriculture

Position available immediately for a soil fertility specialist or soil

biologist to study impacts of rotational grazing systems on soil

biological, chemical, and physical properties. This effort is part of a

large project to develop and test indicators that will help farmers monitor

ecological health and financial and family quality of life changes

resulting from adoption of management intensive grazing. The person in

this position will work closely with a dynamic and diverse group of

researchers/educators, including university scientists, agency and non-
profit personnel, and farmers. The project is funded by the Minnesota

Institute for Sustainable Agriculture, a coalition of farmers, sustainable

agriculture community members, and university faculty, students, and

administrators.

Laboratory and field studies will be conducted jointly under the direction

of Dr. Deborah Allan (Soil Science) and Dr. Linda Kinkel (Plant

Pathology). Initial appointment is for one year with likely extension to

two years. Salary is $30,000 per year plus health benefits. Requirements

include a Ph.D. in soil science or a related field, knowledge of

statistics, experience working with complex data sets, good communication

skills, and the ability to work with diverse audiences. Applicants should

send curriculum vitae, a description of research interests and goals, a

dissertation abstract, and names and addresses of three references to Dr.

Deborah Allan, Dept. of Soil Science, 439 Borlaug Hall, University of

Minnesota, St. Paul, MN 55108; 612/625-3158; FAX 612/625-2208. Deadline:

1 March 1994 or until position filled. For further information, contact

Dr. Allan or Mr. George Boody, Land Stewardship Project 612/433-2770.

The University of Minnesota is an equal opportunity educator and employer

and specifically invites and encourages applications from women and

minorities.

Linda Kinkel
Department of Plant Pathology
495 Borlaug Hall, 1991 Upper Buford Circle
University of Minnesota
St. Paul, MN 55108 PHONE (612) 625-0277, FAX (612) 625-9728

There is a new Environmental Science (ES) undergraduate degree offered by
our college. None of its core courses or its sub-majors offered includes
any course in Soil Science. The group that put it together pushed only
their agenda forward. Well, the ES degree exists now and I'm still trying
to get a Soil Science Major to be a part of this larger ES program.

I'm puting together a "Justification" package to convince the administration
that the original group made an error in leaving us out. (There are the
usual heavy weights from other departments & their "my-turf" mentalities
to deal with here.) I am not really keen on this.

** If you have ideas to share or have put together a similar package before,
** then please share it with me. Many heads are better than one, right?

Thanks a million,

C.P. Schulthess
Asst. Prof.
Dept. of Plant Science

Cristian P. Schulthess
Internet: CSchulth@canr1.cag.uconn.edu * *
Phone: 203-486-1943 Fax: 203-486-0682 * =============== ***
Address: Univ. of Connecticut * Soil & *****
Dept. of Plant Science, U-67 ***** Environmental * ___
W.B. Young Bldg., Room 118 *** Chemist * +. .+
__________Storrs, CT 06269___________________* ================ *__ ( )
o

Dr. Schulthess wrote:
>
> There is a new Environmental Science (ES) undergraduate degree offered by
> our college. None of its core courses or its sub-majors offered includes
> any course in Soil Science. The group that put it together pushed only
> their agenda forward. Well, the ES degree exists now and I'm still trying
> to get a Soil Science Major to be a part of this larger ES program.
>
> I'm puting together a "Justification" package to convince the administration
> that the original group made an error in leaving us out. (There are the
> usual heavy weights from other departments & their "my-turf" mentalities
> to deal with here.) I am not really keen on this.
>
> ** If you have ideas to share or have put together a similar package before,
> ** then please share it with me. Many heads are better than one, right?
>
> Thanks a million,
>
> C.P. Schulthess
[.Sig deleted]

The Department of Soil and Water Science at U. of Arizona kind of went the other
way around on this one. Thewy started as traditional Soil Science
but decided that to increased undergrad enrollment, an
Environmental Science degree should be offered. It worked like a
charm as far as enrollment, but soil science is clearly
emphasised in the curriculum. I feel an Environmental Science
degree without some emphasis on soils would be a poor choice for
a degree curriculum unless of course the degree is more oriented
toward policy issues. What _is_ 'Environmental Science' anyway?

You might want to contact Dr. Peter Weiringa, Department Chairman
of the Soil and Water Sci. Dept. at Univ. of AZ, Tucson, AZ
(85721) about how they dealt with this issue.

Jerome Pier ,
jp@unl.edu

Dear C.P.
My understanding of Ct environmental law indicates that more
than most other states in Ct wetland delineation is determined by soil
series. In most cases, veg and hydrology are secondary determinants because
most development is onm ag lands, leaving little primary evidence of wetland
occurrence. In the 80's, little development took place that did not involve
a discussion of soils mapping and or genesis because of the strict soil-
based wetland laws the state passed.
Is this no longer the case or is development just a little slow\
now so the issue is neatly side-stepped in favor of a political sci. course.
The campus wags know the above. Many of the physical scientist made some
money adding their two cents to controversies surrounding wetland/soil
issues. REmind them of that and/or just wait for development to begin again
and they will come to you.

Michael Folkoff
Dept of Geography
Salisbury State Univ.
Salisbury Md 21801
410-543-6462

How's Harvey L- give him my best.

Dr. Schulthess,
Just a suggestion from a neighboring state, perhaps you should contact
your collegues in the Society of Soil Scientists of Southern New England.
Dr. William Wright, Dep't. Chair of the Department of Natural Resources Science
at the Univ. of R.I., (401) 792-2495 is the President. He can put you in touch
with a number of you fellow soil scientists that have done what you seem to be
attempting to do. One good contact in Ct. is Edward Sauter in Storrs. He is a
retired SCS State Soil Scientist. Good Luck!
Peter.
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