Archive AGMODELS-L: file log9406, part 1/1, size 20057 bytes:

------------------------------ Cut here ------------------------------

Dear List Subscribers,

The May archives are now avaiable for Agmodels-L and
Soils-L. To retrieve the archives send the following email
message to listserv@unl.edu:

get LISTNAME log9405

where 'LISTNAME' refers to either agmodels-l or soils-l. If you
have any difficulty accessing the archives let me know.

Sincerely,

Jerome Pier
Agmodels-L and Soils-L List Owner
jp@unl.edu

GET LISTNAME LOG9405

get LISTNAME log 9405

get LISTNAME log9405

>
> get LISTNAME log9405
>
>
>
>
Dear Darin,

Send this command to listserv@unl.edu and not to the list
address. Also you must explicitly put the specific name of the
list in place of LISTNAME.

Sincerely,

Jerome Pier
AGMODELS-L AND SOILS-L List owner
jp@unl.edu

get agmodels-l log9405

Darrin--
>
> get agmodels-l log9405
>
You've almost got it right....but the message above should be sent to:

LISTSERV@unl.edu

rather than to the list "agmodels-l@unl.unc".....

The difference is confusing at first.

There is a computer robot that reads the incoming mail....
when the mail is addressed to "agmodels-l@unl.edu", the robot
knows that there really isn't a person named "agmodels-l". So
the robot *resends* copies of your mail message to *everyone* on
the AGMODELS-L list of subscribers. :^) Which is why we are
seeing your mis-addressed attempts to get the log files.

On the other hand, sometimes mail comes through addressed to:
"listserv@unl.edu"....and the robot says: "Hey! Mail addressed to
me? I wonder what this person wants?" And of course, the message
is "get agmodels-l log9405"....

The robot sees the "get" and knows that the person wants something
out of one of the virtual file cabinets...which file cabinet?
Well, the "agmodels-l" file cabinet....which file? "log9505"...
the robot looks and sure enough, there really is a file by that name...
so the robot sends that file back *according* to your return address
on the email you sent to the listserv robot.

Hope it helps you and the *others* who have been making the same mistake.

This is worth learning because *all* email robots known as LISTSERV
work the *same* way no matter which computer they are on in the world...
and there are *thousands* of LISTSERV robots in this mortal world.

Steve Modena nmodena@unity.ncsu.edu

FORMAL REQUEST FOR DISCUSSION (RDF) ON
sci.agriculture.sdi

(unmoderated group)

With increasing world population, dwindling water resources
and imposed environmental regulations, agricultural land will
be expected to produce more food and fiber than ever before.
Irrigated land is usually the most productive since climate
and contrlled soil moisture are more reliable than the more
humid rain fed areas. Irrigation water is traditionally
delivered by way of flood basins, furrow runs, sprinklers and
most recently (the last 20 years) drip irrigation. A new
frontier is emerging in irrigated agriculture whereby the drip
irrigation line is buried below the soil surface. This is known
as subsurface drip irrigation (SDI). It has been shown in
research trials and production agriculture that SDI can save
water, dramatically lower fertilizer use, reduce nitrate
pollution into the ground water and lower energy costs.
This emerging technology could benefit any irrigated region in
the world. Design and management ideas are still in their
infancy. Worldwide information exchange is absolutely necessary
to expedite this technology.

Any objections to this RFD will be considered and, if determined to
be appropriate, incorporated. The discussion will last for 21 days.
If no major changes are required to the proposed charter, then
a Call for Votes will then be issued.

This RFD is being posted in concordance with the guidelines set
in "How to Create a New Usenet Newsgroup". Please refer to this
document if you have question about the newsgroup creation process.

This RFD is being crossposted to alt.agriculture, sci.agriculture and
the listserv AGMODELS-L at UNL.EDU

This RFD was prepared by Richard M. Mead, Soil Scientist, USDA-ARS
(MEAD2513@AOL.COM).
I am associated with a U.S. agricultural research laboratory
which studies this new SDI technology. The people I work with
at this laboratory are international experts on the subject.
This newsgroup is intended not to benefit or hinder this lab, but
rather help others worldwide to become educated and understand
the principles of SDI.

Discussion should take place in newsgroup news.groups of USENET

The following post-doctoral position is open with the Great Plains Systems
Research Unit, Fort Collins, Colorado. This position will be filled
immediately. Please send inquiries to:

+---------------------------------------++---------------------------------+
| Dr. Jon D. Hanson || Comm: (303)490-8323 |
| USDA, Agricultural Research Service || Fax: (303)490-8310 |
| Great Plains Systems Research || jon@gpsrv1.gpsr.colostate.edu |
| 301 S. Howes, P.O. Box E || FTS2000: a03jonhanson |
| Fort Collins, Colorado 80522 || |
+---------------------------------------++---------------------------------+

__________________________________________________________________________

Characterizing Root Growth and Water and Nitrogen Uptake
Under Stress Conditions and Their Effects on Range and Crop Production

Part of the mission of our research unit is to determine areas where further
knowledge is needed to understand how to best manage agricultural systems.
As a result of our continued work on comprehensive simulation models, such
as SPUR2 and the Root Zone Water Quality Model (RZWQM), we have determined
that our understanding of root growth, root distribution within the soil,
and the associated processes of water and nutrient uptake are not well
understood. These processes are critical in determining sustainable
management practices because rangelands are ultimately controlled by below-
ground processes. Our current models predict that grazing systems and
stocking rates are the primary mangement options a land manager can
manipulate to develop a sustainable system. Below-ground processes must be
better understood if we hope to develop models that are useful for
predicting the impacts of various management strategies on production and
sustainability. Two primary questions we wish to address in this research
include 1) What environmental variables control water and nutrient uptake
as related to root growth and distribution? and 2) How does partial removal
of the canopy affect carbon partitioning between roots and shoots?

Objectives:

1. Investigate the effect of grazing systems, stocking rate, and water
and nutrient stress on carbon partitioning between roots and shoots,
root distribution through the soil profile, and water and nutrient
uptake of selected plant species (including rangeland and crops).

2. Refine and validate a process-oriented model that describes root
distribution and plant water and nutrient uptake for range- and
crop-land plants.

Approach and Methods: Experimental data already available in the literature
will be to analyzed to refine hypotheses relating to root growth and water
and nutrient uptake by roots. Field and greenhouse experiments will be
designed to determine the effect of water and nutrient availability on
plant carbon partitioning between roots and shoots. Root growth and root
distribution will be determined in response to several grazing systems and
stocking rates at prevailing and modified soil water levels. Soil organic
matter and root distribution will be measured from at least two soil depths
within the profile for each grazing system and stocking rate combination.
Greenhouse studies will be designed to investigate the effect of nutrient
pooling on root development. These data will be used to improve the model
framework currently used in whole-systems models to predict plant growth
and development.
___________________________________________________________________________

Problem in measuring incoming solar radiation!!

I am having difficulty in measuring incoming solar radiation for use
in a rice crop model development in Australia and would appreciate
some comments.

Currently I have two total radiation sensors that give daily
measuremnets of solar radiation. However as they have different
spectral response, the measured values also differ. The can differ by
up to 1 MJ/m2/day (more than 3% error.

The two sectral responses as stated by the manufacturer are

1) Peak 700nm
70% response points at 500 nm and 900 nm

2) Peak at 900 nm
< - 3dB from 500 to 1000 nm

Which of the two resposnes should I be using to measure incominmg
solar radiation. The choice will make up to 5% difference in the
simulations.

Thanks for any Help

\
\ @@@@
\ @ @ Robert L. Williams
\ | / NSW Agriculture Yanco Australia
\ |/ Rice Crop Physiology
\| / Williarl@agric.nsw.gov.au
~~~~~~~~|~~/~~~~~~~~~~
|/
________|_____________
"Life is something to do when you can't get to sleep." Fran Levowitz

set agmodels-l digest

Robert L. Williams asks:

> The two sectral responses as stated by the manufacturer are
>
>1) Peak 700nm
> 70% response points at 500 nm and 900 nm
>
>2) Peak at 900 nm
> < - 3dB from 500 to 1000 nm
>
>Which of the two resposnes should I be using to measure incominmg
>solar radiation. The choice will make up to 5% difference in the
>simulations.

If your choice is either/or it seems clear that #1 corresponds more
closely to the action spectrum for photosynthesis.

Ricardo Salvador | Internet: rjsalvad@IASTATE.EDU | "Thou art a little
1126 Agronomy Hall | BITNET: a1.rjs@ISUMVS | soul bearing about
Iowa State University | Voice: (515) 294-9595 | a corpse."
Ames, IA 50011-1010 | FAX: (515) 294-8146 | -Marcus Aurelius-

sub agmodels-l
------------------------------ Cut here ------------------------------