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Hello,

I'm a student and I'm working on a watering system using fuzzy logic.
As we want to simulate the system on a PC, we need a model of common
flower(s) to improve the system. (need of water, quantity of water which
is pumped by the flower and when...)

I wonder whether some models are available by ftp or not.

Any hint would be welcome.
Thanks

F. Magron
E-mail magron@enstb.enst-bretagne.fr

Hi!

Due to the number of requests I've received requesting info. on fuzzy
logic for ag. and forestry modelling, I am forwarding below a list of the
articles that I've found to date. With respect to fuzzy set theory
itself, perhaps the best introduction to the subject is H.-J. Zimmermann's
book: Fuzzy Set Theory and its Applications, 2nd, revised edition,
published by Kluwer Academic Publishers, 1991.

Best regards,

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Robert J. Flick, Agricultural Economics, UBC |
| e-mail: flick@unixg.ubc.ca |
| phone: 604-327-9854 |
| addr: 6454 Argyle St. Vancouver, B.C. V5P-3K3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Reference list:

Tang Huajun & E. Van Ranst, "Testing of Fuzzy Set Theory in Land
Suitability Assessment for Rainfed Grain Maize Production", Pedologie,
XLII-2, p129-147, 1992;

Tang Huajun et.al., "Land Suitability Classification Based on Fuzzy Set
Theory", Pedologie, XLI-3, p277-290, 1991;

Guillermo Mendoza & William Sprouse, "Forest Planning and Decision-Making
under Fuzzy Environments: An Overview and Illustrations", Forest Science,
Vol. 35, No.2, p481-502, 1989;

David Roberts, "Analysis of Forest Succession with Fuzzy Graph Theory",
Ecological Modelling, 45, p261-274, 1989;

Robert Bosserman & Rammohan Ragade, "Ecosystem Analysis using Fuzzy Set
Theory", Ecological Modelling, 16, p191-208, 1982;

Inakwu Odeh et.al., "Fuzzy-c-Means and Kriging for Mapping Soil as a
Continuous System", Soil Sci. Soc. Am. J., Vol.56, Nov-Dec., 1992;

P.A.Burrough, "Fuzzy Mathematical Methods for Soil Survey and Land
Evaluation", J. of Soil Sci., 40, p477-492, 1989;

D.L.Schmoldt, "An Influence Model for Qualitative Simulation of Ecological
Systems", Artificial Intelligence and Growth Models for Forest Management
Decisions", 1989;

James Pickens, John Hof, and E.T.Bartlett, "Fuzzy Goals, MAXIMIN
Programming, and Natural Resource Management", (? Proc. of the Int'l
Symposium on Systems Analysis and Management Decisions in Forestry,
Valdivia, Chile?);

Bruce Bare and Guillermo Mendoza, "Fuzzy Programming Approaches in
Handling Uncertainty and Imprecision in Timber Harvest Scheduling", (in
above?)

Bruce Bare and Guillermo Mendoza, "Timber Harvest Scheduling in a Fuzzy
Decision Environment", Can.J.For.Res., Vol.22, 1992;

Bruce Bare and G.Mendoza, "A Soft Optimization Approach to Forest Land
Management Planning", Can.J.For.Res., Vol.18, 1988;

A.B. McBratney and A.W. Moore, "Application of Fuzzy Sets to Climatic
Classification", Agricultural and Forest Meteorology, 35, p165-185,
1985;

William Roush, "Fuzzy Decision Analysis", Egg Industry, May, 1989;

Robert Flick, "Modelling Management of Agricultural Ecosystems using
Fuzzy Set Theory: Methodological Issues", paper presented at the joint
meetings of the Western Agricultural Economics Association and the
Canadian Agricultural Economics and Farm Management Society, 1993,
Edmonton, Alberta.

Please unsubscribe, Thanks.

>
> Please unsubscribe, Thanks.
>
Although it is within my power to unsubscribe you, I would
prefer that you do it yourself if possible. Just send email to
listserv with the following message:

unsub agmodels-l

and that should do it. If you have further problems please let me
know. Thanks for subscribing to the list.

Sincerely,

Jerome Pier
jp@unl.edu

I use the IBSNAT soil N model in my potato model, SIMPOTATO, with
sometimes poor results. It seems that net release of nitrogen from
organic sources (humus and crop residue) is too slow in the spring
and early summer in dry, high latitude soils (40-60 N lat) with low
organic matter (.5-1.5%). Yacob Pachepsky suggested lowering the
range of temperature where mineralization is allowed which helped
some, but not near enough. Instead of starting at 5 C it now starts
at -8 C. Multiplying the mineralization rate overall seems to result
in too much N being released in late summer. I will also be adjusting
the proportions of residue in the very fast, fast, and slow pools in
the model.

Does anyone have any other thoughts on simulating N cycling between
mineral and organic forms?

Tom

Tom Hodges Cropping Systems Modeler ___ ___
USDA-ARS / \_/ \
Rt. 2, Box 2953-A Telephone: 509-786-2226 | |
Prosser, WA 99350 \______/^\/
USA potato tuber
thodges@beta.tricity.wsu.edu
=====================================================================
...photosynthesis makes the world go around... Mr. Potato Head

I don't know the geneaology of SIMPOTATO, so I don't know which models
it is related to, but have you tried some of the other N cycling models
such as NCSWAP or NTRM?

Jonathan Haskett
jhaskett@asrr.arsusda.gov

Sure I'll be glad to to talk to any one about fuzzy stuff.
Gordon

Gordon Couger
Biosystems & Agricultural Engineering
Oklahoma State Universtiy Stillwater OK

I found an old paper that presents a more mechanistic approach to
modeling N mineralization. It describes mineralization based on the rate of
microbial growth (from Monod kinetics) and the C:N ratio of the
residue/waste/organic stuff. It's very general and is more intuitive than
many empirical equations I've seen. The reference is as follows:

Parnas, Hanna. 1975. Model for decomposition of organic material by
microorganisms. Soil Biology and Biochemistry. Vol. 7. pp. 161-169.

I hope that helps.

I also have a question for Jerome Piers. How do we change our email
address with the list server?

Tess Gidley

tmgidley@eos.ncsu.edu
and
tess@dem.ehnr.state.nc.us

Forwarded message:

>Sender: Agriculture Discussion <AGRIC-L@uga.cc.uga.edu>
>From: "LEO VAN DER HEIJDEN, AB-DLO, WAGENINGEN, NL" <L.A.M.VAN.DER.HEIJDEN@AB.AGRO.NL>
>Subject: New Electronic Newsletter for Agro-Ecosystems Modelling

>For your information:

----- Begin message from IN%"CAMASE-L@nic.SURFnet.nl" 6-Apr-94

>From: IN%"CAMASE-L@nic.SURFnet.nl" "Quantitative Methods of Research on Agricultural Systems and the Environment" 6-APR-1994 15:52
To: Multiple recipients of list CAMASE-L <CAMASE-L@nic.SURFnet.nl>
Subj: CAMASE_NEWS No. 1, March 1994

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

N E W S L E T T E R

O F

A G R O - E C O S Y S T E M S

M O D E L L I N G

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Published by AB-DLO March 1994, No.1
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\==================================================================\
\ \
\ CONTENTS \
\ \
\ REGISTER OF AGRO-ECOSYSTEMS MODELS \
\ ANNOUNCEMENTS \
\ UPCOMING MEETINGS \
\ NEW BOOKS \
\ THE MARKET PLACE, WITH: \
\ MODELLING AND AGRO-ECOLOGICAL RESEARCH IN WAGENINGEN \
\==================================================================\

====================================================================
EDITORIAL

CAMASE_NEWS is a new Newsletter. It is aimed at scientists
interested in modelling in agro-ecosystems, and should improve
their access to appropriate models, data, and related tools,
instruction materials. Initially, we focus at EU-12 scientists.

CAMASE_NEWS will provide short, informative messages on modelling
and simulation issues and developments, a report on progress in
the model register (more below) and other data bases,
announcements, and calls for collaboration. Hard copies and
electronic copies of CAMASE_NEWS are distributed every quarter to
those on our mailing list (already over 100 names). The Newsletter
is also available through the SURFNET distribution list 'CAMASE-L';
back dated issues and specific items can be retrieved with
keywords.

CAMASE_NEWS is the result of an initiative of the 1992 workshop on
Modelling and Agroclimatology of the European Society for
Agronomy, and is supported by a grant of the European Union for
the Concerted Action to stimulate development and testing of
quantitative Methods for research on Agricultural Systems and the
Environment (CAMASE).

Our thanks are due to ESA, for help in producing the initial mailing
list, and to Ruud Verkerke, for the design of CAMASE_NEWS.

Frits Penning de Vries,
Marja Plentinger
====================================================================

* * *

THE REGISTER OF AGRO-ECOSYSTEMS MODELS

k e y w o r d s:
s i m u l a t i o n, m o d e l s,
m o d e l l i n g t o o l s,
d a t a b a s e,
s t a n d a r d i z a t i o n

CAMASE is setting up a register of models. We will attempt to
catalogue most of the relevant simulation models for research,
education and application used in Europe in the broad area of crop
production, nutrient cycling, farming systems, and of many of the
shells and tools for modelling. In this way, we intend
- to increase awareness among scientists of existing models;
- to increase accessibility of these models;
- to stimulate harmonization and compatibility of models by example.
In the register, every model is described in a fixed format in
about one page. It will have the form of a computerized data base
of model profiles, accessible through a network. Initially the
information from the Register will be free.
The next issue of CAMASE_NEWS will introduce the Register
properly, with an example. We hope that you will share with us and
other European colleagues the information about your models.

* * *

ANNOUNCEMENTS

k e y w o r d s:
C A M A S E, c o r e g r o u p s,
p r o d u c t i o n s y s t e m s r e s e a r c h,
m o d e l l i n g, n e w s l e t t e r,
r e g i s t e r, d i s t r i b u t i o n l i s t

CAMASE is an EU-supported concerted action of five European groups
that are leading in the area of production systems research. The
core groups for CAMASE are:
- the Copenhagen research team (Denmark): leadings drs. Niels Erik
Nielsen, Soren Hansen, Henry E. Jensen (The Royal Veterinary and
Agricultural University); strength in modelling nitrogen losses
and crop growth and production.
- the Toulouse research team (France): leading dr. Philippe Debaeke
and Mr. Maurice Cabelguenne, Institute National de la Recherche
Agronomique; strength in modelling crop production systems.
- the Cordoba research team (Spain), leading dr. Francisco
Villalobos (Universidad de Cordoba, Dept. Agronomy) and dr.
Luciano Mateos (CSIC, Instituto de Agricultura Sostenible);
strength in modelling irrigation systems.
- the Edinburgh research team (U.K.): leading prof.dr. Barry Dent
and dr. Graham Russell, University of Edinburgh; strength in farm
household modelling and expert systems.
- the Wageningen research teams (The Netherlands), coordinated by
dr. Peter Leffelaar (Agricultural University, Theoretical
Production Ecology), dr. Aad van Wijk (DLO-Winand Staring Centre)
and dr. Frits Penning de Vries (DLO-Institute for Agrobiology and
Soil Fertility Research); strengths in modeling crop and soil
processes, dynamics of pests and weeds, crop production systems,
methodology, training.

The objectives of CAMASE are to advance quantitative research on
agricultural systems and their environment in the EU-countries, by
improving systems research in participating institutes through
exchange and standardization of concepts, approaches, knowledge,
computer programs and data. Specific objective are:
- to produce a newsletter
- to produce a model register
- to stimulate research on production systems.
CAMASE started in November 1993, and has been funded for three
years. Marja Plentinger and Frits Penning de Vries coordinate the
project. We held our first workshop with core teams in December,
where plans were developed to achieve the three objectives. The
ESA-congress provides a good opportunity to review the first
issues of the Newsletter and the first versions of the Register.

DISTRIBUTION LIST. We received requests for copies of the
CAMASE_NEWS mailing list. Please let us know if you prefer that
your name is excluded from such copies.

* * *

UPCOMING MEETINGS

- International Symposium on Fingered Flow in Unsaturated Soil: from
Field to Model. DLO-Winand Staring Centre, Wageningen, 20 April
1994.
Contact: Drs. C.J. Ritsema, DLO-Winand Staring Centre, P.O.Box 125,
6700 AC Wageningen, The Netherlands
Telephone: +31-8370-74266
Telefax: +31-8370-24812

- Ecology and Modelling of Potato Crops under Conditions Limiting
Growth. Summer School, Second International Modelling Conference
17, 18 and 19 May 1994.
Contact: dr. A.J. Haverkort, Department of Crop Physiology, DLO-
Research Institute for Agrobiology and Soil Fertility, P.O. Box 14
6700 AA Wageningen, The Netherlands
Telephone: +31-8370-75855
Telefax: +31-8370-23110
or: dr. J. Vos, Department of Agronomy, Agricultural University,
Haarweg 333, 6709 RZ Wageningen, The Netherlands
Telephone: +31-8370-83042
Telefax: +31-8370-84575

- The Third International Conference for Systems Integration. Sao
Paulo City - Brazil. July 30 th - August 6th 1994.
Contact: Prof. Peter A. Ng, IIISis -USA Office- New Jersey Inst.
of Technology, University of Heights, Newark, NJ 07102 USA
Telephone: (1)(201) 596-3387
Telefax: (1)(201) 596-5777
Or: Prof. Fuad Gattaz Sobrinho
Telephone: (55)(192) 41-4504
Telefax: (55)(192) 41-3098

- Scenario Studies for the Rural Environment. 5th anniversary
symposium of the DLO-Winand Staring Centre. Wageningen, 12-15
September 1994.
Themes: Regional soil and water management, nature development and
landscape quality, and impact of scenario studies on land use
planning.
Contact: dr. J.F.T. Schoute, DLO Winand Staring Centre, P.O. Box
125, 6700 AC Wageningen, The Netherlands
Telephone: +31-8370-74274
Telefax: +31-8370-24812

- The third Congress of the European Society for Agronomy will be
held at the Teatro Congressi of Abano Terme (Padova), 18-22
September, 1994. Special workshops on Modeling and
Agroclimatology.
Contact (Secretariat): SISTEMA CONGRESSI, Via Jappelini 12, 35121
PADOVA, ITALY
Telephone: +39-49-651699
Telefax: +39-49-651320

* * *

NEW BOOKS

- AARD/LAWOO. 1993. Acid Sulphate Soils in the Humid Tropics:
simulation model of physical and chemical processes to evaluate
water management strategies. Final Report Res. Progr. Acid
Sulphate Soils in the Humid Tropics, vol 3. Agency for
Agricultural Research and Development (AARD), Jakarta and Land and
Water Research Group (LAWOO), Wageningen. 248 pp..
- Goudriaan, J., S.C. van de Geijn & J.S.I. Ingram (Eds.), 1993.
GCTE Focus 3 Wheat Modelling and Experimental Data Comparison
Workshop Report. Lunteren, Netherlands 2-4 November 1993. GCTE
(Global Change & Terrestrial Ecosystems).
- Hansen, S., H.E. Jensen, N.E. Nielsen & H. Svendsen, 1994. The
Soil Plant System Model DAISY: Basic principles and modelling
approach. Jordbrugsforlaget. The Royal Vetenary and Agricultur
University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark,
pp. 137, DEK 100,00.
- Kropff, M.J. & H.H. van Laar (eds.), 1993. Modelling crop - weed
interactions. Wallingford: CAB International. 274 p..
- Leffelaar, P.A. (Ed.), 1993. On systems analysis and simulation of
ecological processes. Kluwer Academic Publishers, Dordrecht,
Netherlands 308 pp..
- Nonhebel, S., 1993. The importance of weather data in crop growth
simulation models and assessment of climatic change effects. PhD
thesis, Wageningen Agricultural University. 144 pp..
- Noij, I.G.A.M., B.H. Janssen, L.G. Wesselink & J.J.M. van
Grinsven, 1993. Modeling Nutrient and Moisture Cycling in Tropical
Forests. The Tropenbos Foundation. Wageningen. 195 pp.
ISBN 90-5113-016-3.
- Rossing, W.A.H., 1993. On damage, uncertainty and risk in
supervised control: aphids and brown rust in winter wheat as an
example. PhD thesis, Wageningen Agricultural University. 201 pp..
- Smaling, E., 1993. An agro-ecological framework for integrated
nutrient management, with special reference to Kenya. PhD thesis,
Wageningen Agricultural University. 250 pp..
- Teng, P.S. & F. Penning de Vries (eds.), 1992. Systems approaches
for agricultural development. Agricultural Systems 40, vols 1-3.
309 pp..
- Wetenschappelijke Raad voor het Regeringsbeleid., 1992. Ground for
Choices. Four perspectives for the rural areas of the European
Community. Reports to the Government, 42.The Hague, SDU
Uitgeverij. SSN 0169-6734; 42. 149 pp. ( also in French).
- Wopereis, M.C.S., 1993. Quantifying the impact of soil and climate
variability on rainfed rice production. PhD thesis, Wageningen
Agricultural University. 188 pp..

* * *

THE MARKET PLACE

Do you feel that research of your team is insufficiently known? In
this section, we welcome a short description of your systems
research group. Descriptions of the CAMASE core groups are already
lined up for this and upcoming issues.
We will also welcome offers of specific expertise or data, and
calls for the same.

MODELLING AND AGRO-ECOLOGICAL RESEARCH IN WAGENINGEN
'Wageningen' harbours the Agricultural University (WAU) with 60
Departments, and 16 large Institutes of the Agricultural Research
Department (in Dutch: DLO) of the Ministry of Agriculture, Nature
and Fisheries. Over the past two decades, many scientists of these
organizations adopted systems analysis and modelling as a part of
their research and teaching in crop, soil and animal science and
agrosystems research. Hundreds of papers and tens of models and
documents have been published. After recent reorganizations, three
groups emerged that are particularly active in this area: the
Research Institute for Agrobiology and Soil Fertility (AB-DLO),
formerly the CABO (Wageningen) and the IB (Haren), the graduate
school Production Ecology (PE-WAU) and the DLO-Winand Staring
Centre (SC-DLO). These groups participate in CAMASE, are very
interested to share results and experiences with colleagues in
Europe, and are eager to learn from you. Please write or e_mail us
if you feel like it.

Major publications from Wageningen modelers are found in the
series Simulation Monographs (publisher: PUDOC, Wageningen: 30
volumes), and CABO-TPE Simulation Reports (35 issues). The second
series is continuing (address: as for this Newsletter), the first
is succeeded by two new series: 'Current Issues in Production
Ecology', and 'Systems Approaches for sustainable Agricultural
Systems', both by Kluwer, Dordrecht, the Netherlands. Available
issues from these series will be listed in the next CAMASE_NEWS.
The group further provides teaching programs, computer aided
instructions, PhD and MSc programs in Crop and Plant Sciences, and
other training programs in The Netherlands and abroad. For further
information, contact dr. Frits Penning de Vries at AB-DLO
(P.O.Box 14, 6700 AA, Wageningen), dr. Peter Leffelaar at PE-WAU
(P.O.Box 430, 6700 AK Wageningen), or dr. Aad van Wijk at SC-DLO
(P.O. Box 125, 6700 AC, Wageningen).

Over 50 scientists collaborate in Wageningen in an informal
simulation group on a range of topics. They use many different
models, many of which stem from a common base.
Current activities of AB-DLO and PE-WAU address production and
environmental issues in natural and agricultural ecosystems at
integration levels with time coefficients of hours (plants,
pests), days (soils, crops) and years (production systems). The
research is to improve understanding of systems, but also leads to
designing of improved systems and their optimization. Activities
include the development, testing and documentation of:
- standard modules for crop, soil and pest modelling;
- a 'simulation environment' or 'shell' for use with the standard
modules per se and in cropping systems research, plus user
friendly documentation;
- a method for in-depth analysis of the inherent accuracy of crop
modelling, and consequences of parameter uncertainty;
- more computer aided instructions programs on systems analysis and
crop modelling, and other training materials for use at MSc, PhD
and post doc levels;
- simulation models of competition between plants (and trees) for
the capture of the essential resources for plant growth (i.e.
light, water and nutrients).
The research SC-DLO focuses on problems of physical planning,
environmental protection and water management in rural areas to
support well-balanced decision making. Agro-ecosystem modelling
activities are on:
- transport of water and substances (nutrients and pesticides) in
soils;
- soil-water-plant-atmosphere relationships;
- regional modelling: unsaturated zone models linking regional
ground and surface water models.
The scale of model application ranges from field to regional
level. Fields of application are land evaluation (crops, pasture,
forestry); water management (interactions agriculture-nature-
ground water resources, drainage, irrigation); soil protection/
environmental impact studies (soil acidification, emissions of
nutrients and pesticides to ground and surface waters); scenario
studies for rural land use and environmental problems.

Many of the Wageningen models were written in the simulation
language CSMP, and later PCSMP for PC's. Most models are now
produced in FORTRAN, within a framework called FSE ( the FORTRAN
Simulation Environment) that ensures standardization and
compatibility. A translator has been developed to translate simple
CSMP models into modules for FSE, so that the advantages for
teaching of a real simulation language are retained. This
standardization of models and modelling approaches is expected to
continue.
Interesting developments occur in the field of linear programming.
LP-models exist to optimize production of milk, tulip bulbs (how
very Dutch!) and arable crops on farms. It is also being applied
to optimization of land use in developing countries, and the
European Community. An essential feature of the method is that
consequences of conflicting goals, such as maximizing crop
production and minimizing NH3-loss and pesticide use, can be
compared objectively. The method is referred to as 'multiple goal
linear programming', and helps to quantify options for integrated
agricultural production.

Another important line of research aims to couple Geographic
Information Systems with crop and soil models. While this is
proceeding quite well at a technical level, there are important
issues of aggregation, spatial heterogeneity and data scarcity
that require careful analysis.

====================================================================
CAMASE: A CONCERTED ACTION FOR THE DEVELOPMENT AND TESTING OF
QUANTITATIVE METHODS FOR RESEARCH ON AGRICULTURAL SYSTEMS AND THE
ENVIRONMENT.

The objectives of CAMASE are to advance quantitative research on
agricultural systems and their environment in the EU-countries, by
improving systems research in participating institutes through
exchange and standardization of concepts, approaches, knowledge,
computer programs and data.
CAMASE relates to a small network of research groups, and a broad
group of scientists receiving information. The network consists of
scientists from five groups in Europe: Denmark (Royal Veterinary
and Agricultural University, Copenhagen), France (Institute
Nationale de la Recherche Agronomique, Toulouse), Spain (Cordoba
University, Cordoba), Scotland (Institute of Ecology and Resource
Management, Edinburgh) and The Netherlands (AB-DLO , TPE-WAU and
SC-DLO, Wageningen).

With CAMASE_NEWS, we aim to improve communication among scientists
working in agro-ecosystem modelling and interested in better
access to appropriate models, data, and related tools, instruction
materials. CAMASE-core groups and others can contribute
spontaneously or will be invited to contribute. Responsibility for
the opinions expressed rests with the authors.

CAMASE_NEWS will appear four times per year. Please submit news
items for CAMASE_NEWS and requests for new subscriptions to:

F.W.T. Penning de Vries/M.C. Plentinger
DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO)
P.O.Box 14
6700 AA WAGENINGEN
The Netherlands
Telephone: +31.8370.75961
Telefax: +31.8370.23110
Internet: camase@ab.agro.nl

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

----- End forwarded message

Does anyone have any information on whether the Parnas (1975) N mineralization
model published in Soil Biology and Biochemistry, Vol. 7, pp. 161-169 has been validated or
has been applied? If you have more information, I would be very appreciative in recieving it.

James McKinion

Does anyone have a turfgrass production model? I had a faculty member who
is teaching an IPM course ask if there was a turf model available to use
with his turf students. It sounds as if he wants an empirical/extension
type model with some weather (and maybe pest) inputs.

Dwight

Dwight S. Fisher Internet: dwight_fisher@ncsu.edu
USDA-ARS
Box 7620
Crop Science Department
North Carolina State University
Raleigh, NC 27695
FAX 919 515 7959
Phone 919 515 7597

Dwight S. Fisher Internet: dwight_fisher@ncsu.edu
USDA-ARS
Box 7620
Crop Science Department
North Carolina State University
Raleigh, NC 27695
FAX 919 515 7959
Phone 919 515 7597

Try the Texas A&M Department of Turf Management. They may have one.

+---------------------------------------++---------------------------------+
| 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 || |
+---------------------------------------++---------------------------------+

Dear Agmodels readers,

I have been a subscriber for some time now, but haven't got round to giving
a formal introduction. I am Rick Bradley, working at the University of
Nottingham in England. My degree studies were in plant physiology &
computing and, since then, I have been working for the British Overseas
Development Administration (ODA).

Through collaboration with many other workers on aid for developing
countries, I have produced (am still improving) a simulation model called
PARCH. It is designed to address the problems of user-friendliness
discussed in this forum over the previous weeks, and thus be more
accessible to the extension officer. However, it is designed with several
levels of complexity, so that breeders, agronomists or hydrologists, as
well as experimental planners can all answer specific questions with it.
PARCH contains a water balance and crop growth model, and is designed
to work optimally in semi-arid areas with low input agriculture (although
it does appear to scale up well to intensive agriculture situations). It
was initially written to improve sorghum husbandry, but is now being
extended to millet, maize, wheat and groundnut.

Part of my work over the next three years is to look at tree/crop
(agroforestry) and weed/crop competition. The remainder of my time will
be spent writing a nutrient sub-model. This is to include mineralization
of manure and other organic matter, as well as immobilisation,
volatalization etc. I have started a literature search and may have some
information which will help Tom Hodges: The whole of Fertilizer Research
March 1991 Vol 27, No. 2-3 is dedicated to nitrogen/crop models, and
contains several different perspectives on the problem. It's heavy going,
but worth a read if you have a spare week or so.

(I hope I haven't sent anyone to sleep with my intro yet!)

The PARCH model has not been written for any commercial gain, and is
purely designed as a tool to help developing agriculture. If anyone
is interested in more details about the model (full documentation and
an EXE version are available), please contact me. Also, I would like to
hear from anyone working in the areas I have covered above who is
interested in any form of collaboration on this aid project. ODA are
keen on this type of collaboration, and may be able to partially fund
useful work.

I look forward to hearing any replies, and apologise for not introducing
myself sooner.

Yours,

Rick Bradley
==== =======
+------------------------------------------------------------------+
| R.G.Bradley, Biometry, | Tel. 0602 516317 |
| Dept. of Environmental Science, | |
| University of Nottingham, | Fax. 0602 516261 |
| Sutton Bonington Campus, | |
| LEICS. LE12 5RD, UK | Email SBZRB@sbn2.nott.ac.uk |
+----------------------------P--A--R--C--H-------------------------+

> From: IN%"agmodels-l@unl.EDU" 11-APR-1994 08:05
> To: Multiple recipients of list <agmodels-l@unl.EDU>
> CC:
> Subj: AGMODELS-L digest 77
>
> Received: from AGRO.NL by PAGV.AGRO.NL; Mon, 11 Apr 94 08:05 MET
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> dekkers@pagv.agro.nl); Thu, 7 Apr 1994 07:34:55 -0500
> Date: Thu, 07 Apr 1994 07:34:55 -0500
> From: agmodels-l@unl.EDU
> Subject: AGMODELS-L digest 77
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> Contents:
> CAMASE_NEWS (fwd) (samodena@csemail.cropsci.ncsu.edu (S. A. Modena))
>
> ----------------------------------------------------------------------
>
> Date: Thu, 7 Apr 94 8:21:27 EDT
> From: samodena@csemail.cropsci.ncsu.edu (S. A. Modena)
> Subject: CAMASE_NEWS (fwd)
>
> Forwarded message:
>
> >Sender: Agriculture Discussion <AGRIC-L@uga.cc.uga.edu>
> >From: "LEO VAN DER HEIJDEN, AB-DLO, WAGENINGEN, NL" <L.A.M.VAN.DER.HEIJDEN@AB.AGRO.NL>
> >Subject: New Electronic Newsletter for Agro-Ecosystems Modelling
>
> >For your information:
>
> ----- Begin message from IN%"CAMASE-L@nic.SURFnet.nl" 6-Apr-94
>
> >From: IN%"CAMASE-L@nic.SURFnet.nl" "Quantitative Methods of Research on Agricultural Systems and the Environment" 6-APR-1994 15:52
> To: Multiple recipients of list CAMASE-L <CAMASE-L@nic.SURFnet.nl>
> Subj: CAMASE_NEWS No. 1, March 1994
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> N E W S L E T T E R
>
> O F
>
> A G R O - E C O S Y S T E M S
>
> M O D E L L I N G
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> Published by AB-DLO March 1994, No.1
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> \==================================================================\
> \ \
> \ CONTENTS \
> \ \
> \ REGISTER OF AGRO-ECOSYSTEMS MODELS \
> \ ANNOUNCEMENTS \
> \ UPCOMING MEETINGS \
> \ NEW BOOKS \
> \ THE MARKET PLACE, WITH: \
> \ MODELLING AND AGRO-ECOLOGICAL RESEARCH IN WAGENINGEN \
> \==================================================================\
>
> ====================================================================
> EDITORIAL
>
> CAMASE_NEWS is a new Newsletter. It is aimed at scientists
> interested in modelling in agro-ecosystems, and should improve
> their access to appropriate models, data, and related tools,
> instruction materials. Initially, we focus at EU-12 scientists.
>
> CAMASE_NEWS will provide short, informative messages on modelling
> and simulation issues and developments, a report on progress in
> the model register (more below) and other data bases,
> announcements, and calls for collaboration. Hard copies and
> electronic copies of CAMASE_NEWS are distributed every quarter to
> those on our mailing list (already over 100 names). The Newsletter
> is also available through the SURFNET distribution list 'CAMASE-L';
> back dated issues and specific items can be retrieved with
> keywords.
>
> CAMASE_NEWS is the result of an initiative of the 1992 workshop on
> Modelling and Agroclimatology of the European Society for
> Agronomy, and is supported by a grant of the European Union for
> the Concerted Action to stimulate development and testing of
> quantitative Methods for research on Agricultural Systems and the
> Environment (CAMASE).
>
> Our thanks are due to ESA, for help in producing the initial mailing
> list, and to Ruud Verkerke, for the design of CAMASE_NEWS.
>
> Frits Penning de Vries,
> Marja Plentinger
> ====================================================================
>
> * * *
>
> THE REGISTER OF AGRO-ECOSYSTEMS MODELS
>
> k e y w o r d s:
> s i m u l a t i o n, m o d e l s,
> m o d e l l i n g t o o l s,
> d a t a b a s e,
> s t a n d a r d i z a t i o n
>
> CAMASE is setting up a register of models. We will attempt to
> catalogue most of the relevant simulation models for research,
> education and application used in Europe in the broad area of crop
> production, nutrient cycling, farming systems, and of many of the
> shells and tools for modelling. In this way, we intend
> - to increase awareness among scientists of existing models;
> - to increase accessibility of these models;
> - to stimulate harmonization and compatibility of models by example.
> In the register, every model is described in a fixed format in
> about one page. It will have the form of a computerized data base
> of model profiles, accessible through a network. Initially the
> information from the Register will be free.
> The next issue of CAMASE_NEWS will introduce the Register
> properly, with an example. We hope that you will share with us and
> other European colleagues the information about your models.
>
>
> * * *
>
> ANNOUNCEMENTS
>
> k e y w o r d s:
> C A M A S E, c o r e g r o u p s,
> p r o d u c t i o n s y s t e m s r e s e a r c h,
> m o d e l l i n g, n e w s l e t t e r,
> r e g i s t e r, d i s t r i b u t i o n l i s t
>
> CAMASE is an EU-supported concerted action of five European groups
> that are leading in the area of production systems research. The
> core groups for CAMASE are:
> - the Copenhagen research team (Denmark): leadings drs. Niels Erik
> Nielsen, Soren Hansen, Henry E. Jensen (The Royal Veterinary and
> Agricultural University); strength in modelling nitrogen losses
> and crop growth and production.
> - the Toulouse research team (France): leading dr. Philippe Debaeke
> and Mr. Maurice Cabelguenne, Institute National de la Recherche
> Agronomique; strength in modelling crop production systems.
> - the Cordoba research team (Spain), leading dr. Francisco
> Villalobos (Universidad de Cordoba, Dept. Agronomy) and dr.
> Luciano Mateos (CSIC, Instituto de Agricultura Sostenible);
> strength in modelling irrigation systems.
> - the Edinburgh research team (U.K.): leading prof.dr. Barry Dent
> and dr. Graham Russell, University of Edinburgh; strength in farm
> household modelling and expert systems.
> - the Wageningen research teams (The Netherlands), coordinated by
> dr. Peter Leffelaar (Agricultural University, Theoretical
> Production Ecology), dr. Aad van Wijk (DLO-Winand Staring Centre)
> and dr. Frits Penning de Vries (DLO-Institute for Agrobiology and
> Soil Fertility Research); strengths in modeling crop and soil
> processes, dynamics of pests and weeds, crop production systems,
> methodology, training.
>
> The objectives of CAMASE are to advance quantitative research on
> agricultural systems and their environment in the EU-countries, by
> improving systems research in participating institutes through
> exchange and standardization of concepts, approaches, knowledge,
> computer programs and data. Specific objective are:
> - to produce a newsletter
> - to produce a model register
> - to stimulate research on production systems.
> CAMASE started in November 1993, and has been funded for three
> years. Marja Plentinger and Frits Penning de Vries coordinate the
> project. We held our first workshop with core teams in December,
> where plans were developed to achieve the three objectives. The
> ESA-congress provides a good opportunity to review the first
> issues of the Newsletter and the first versions of the Register.
>
> DISTRIBUTION LIST. We received requests for copies of the
> CAMASE_NEWS mailing list. Please let us know if you prefer that
> your name is excluded from such copies.
>
>
> * * *
>
> UPCOMING MEETINGS
>
> - International Symposium on Fingered Flow in Unsaturated Soil: from
> Field to Model. DLO-Winand Staring Centre, Wageningen, 20 April
> 1994.
> Contact: Drs. C.J. Ritsema, DLO-Winand Staring Centre, P.O.Box 125,
> 6700 AC Wageningen, The Netherlands
> Telephone: +31-8370-74266
> Telefax: +31-8370-24812
>
> - Ecology and Modelling of Potato Crops under Conditions Limiting
> Growth. Summer School, Second International Modelling Conference
> 17, 18 and 19 May 1994.
> Contact: dr. A.J. Haverkort, Department of Crop Physiology, DLO-
> Research Institute for Agrobiology and Soil Fertility, P.O. Box 14
> 6700 AA Wageningen, The Netherlands
> Telephone: +31-8370-75855
> Telefax: +31-8370-23110
> or: dr. J. Vos, Department of Agronomy, Agricultural University,
> Haarweg 333, 6709 RZ Wageningen, The Netherlands
> Telephone: +31-8370-83042
> Telefax: +31-8370-84575
>
> - The Third International Conference for Systems Integration. Sao
> Paulo City - Brazil. July 30 th - August 6th 1994.
> Contact: Prof. Peter A. Ng, IIISis -USA Office- New Jersey Inst.
> of Technology, University of Heights, Newark, NJ 07102 USA
> Telephone: (1)(201) 596-3387
> Telefax: (1)(201) 596-5777
> Or: Prof. Fuad Gattaz Sobrinho
> Telephone: (55)(192) 41-4504
> Telefax: (55)(192) 41-3098
>
> - Scenario Studies for the Rural Environment. 5th anniversary
> symposium of the DLO-Winand Staring Centre. Wageningen, 12-15
> September 1994.
> Themes: Regional soil and water management, nature development and
> landscape quality, and impact of scenario studies on land use
> planning.
> Contact: dr. J.F.T. Schoute, DLO Winand Staring Centre, P.O. Box
> 125, 6700 AC Wageningen, The Netherlands
> Telephone: +31-8370-74274
> Telefax: +31-8370-24812
>
> - The third Congress of the European Society for Agronomy will be
> held at the Teatro Congressi of Abano Terme (Padova), 18-22
> September, 1994. Special workshops on Modeling and
> Agroclimatology.
> Contact (Secretariat): SISTEMA CONGRESSI, Via Jappelini 12, 35121
> PADOVA, ITALY
> Telephone: +39-49-651699
> Telefax: +39-49-651320
>
> * * *
>
> NEW BOOKS
>
> - AARD/LAWOO. 1993. Acid Sulphate Soils in the Humid Tropics:
> simulation model of physical and chemical processes to evaluate
> water management strategies. Final Report Res. Progr. Acid
> Sulphate Soils in the Humid Tropics, vol 3. Agency for
> Agricultural Research and Development (AARD), Jakarta and Land and
> Water Research Group (LAWOO), Wageningen. 248 pp..
> - Goudriaan, J., S.C. van de Geijn & J.S.I. Ingram (Eds.), 1993.
> GCTE Focus 3 Wheat Modelling and Experimental Data Comparison
> Workshop Report. Lunteren, Netherlands 2-4 November 1993. GCTE
> (Global Change & Terrestrial Ecosystems).
> - Hansen, S., H.E. Jensen, N.E. Nielsen & H. Svendsen, 1994. The
> Soil Plant System Model DAISY: Basic principles and modelling
> approach. Jordbrugsforlaget. The Royal Vetenary and Agricultur
> University, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark,
> pp. 137, DEK 100,00.
> - Kropff, M.J. & H.H. van Laar (eds.), 1993. Modelling crop - weed
> interactions. Wallingford: CAB International. 274 p..
> - Leffelaar, P.A. (Ed.), 1993. On systems analysis and simulation of
> ecological processes. Kluwer Academic Publishers, Dordrecht,
> Netherlands 308 pp..
> - Nonhebel, S., 1993. The importance of weather data in crop growth
> simulation models and assessment of climatic change effects. PhD
> thesis, Wageningen Agricultural University. 144 pp..
> - Noij, I.G.A.M., B.H. Janssen, L.G. Wesselink & J.J.M. van
> Grinsven, 1993. Modeling Nutrient and Moisture Cycling in Tropical
> Forests. The Tropenbos Foundation. Wageningen. 195 pp.
> ISBN 90-5113-016-3.
> - Rossing, W.A.H., 1993. On damage, uncertainty and risk in
> supervised control: aphids and brown rust in winter wheat as an
> example. PhD thesis, Wageningen Agricultural University. 201 pp..
> - Smaling, E., 1993. An agro-ecological framework for integrated
> nutrient management, with special reference to Kenya. PhD thesis,
> Wageningen Agricultural University. 250 pp..
> - Teng, P.S. & F. Penning de Vries (eds.), 1992. Systems approaches
> for agricultural development. Agricultural Systems 40, vols 1-3.
> 309 pp..
> - Wetenschappelijke Raad voor het Regeringsbeleid., 1992. Ground for
> Choices. Four perspectives for the rural areas of the European
> Community. Reports to the Government, 42.The Hague, SDU
> Uitgeverij. SSN 0169-6734; 42. 149 pp. ( also in French).
> - Wopereis, M.C.S., 1993. Quantifying the impact of soil and climate
> variability on rainfed rice production. PhD thesis, Wageningen
> Agricultural University. 188 pp..
>
>
> * * *
>
> THE MARKET PLACE
>
> Do you feel that research of your team is insufficiently known? In
> this section, we welcome a short description of your systems
> research group. Descriptions of the CAMASE core groups are already
> lined up for this and upcoming issues.
> We will also welcome offers of specific expertise or data, and
> calls for the same.
>
> MODELLING AND AGRO-ECOLOGICAL RESEARCH IN WAGENINGEN
> 'Wageningen' harbours the Agricultural University (WAU) with 60
> Departments, and 16 large Institutes of the Agricultural Research
> Department (in Dutch: DLO) of the Ministry of Agriculture, Nature
> and Fisheries. Over the past two decades, many scientists of these
> organizations adopted systems analysis and modelling as a part of
> their research and teaching in crop, soil and animal science and
> agrosystems research. Hundreds of papers and tens of models and
> documents have been published. After recent reorganizations, three
> groups emerged that are particularly active in this area: the
> Research Institute for Agrobiology and Soil Fertility (AB-DLO),
> formerly the CABO (Wageningen) and the IB (Haren), the graduate
> school Production Ecology (PE-WAU) and the DLO-Winand Staring
> Centre (SC-DLO). These groups participate in CAMASE, are very
> interested to share results and experiences with colleagues in
> Europe, and are eager to learn from you. Please write or e_mail us
> if you feel like it.
>
> Major publications from Wageningen modelers are found in the
> series Simulation Monographs (publisher: PUDOC, Wageningen: 30
> volumes), and CABO-TPE Simulation Reports (35 issues). The second
> series is continuing (address: as for this Newsletter), the first
> is succeeded by two new series: 'Current Issues in Production
> Ecology', and 'Systems Approaches for sustainable Agricultural
> Systems', both by Kluwer, Dordrecht, the Netherlands. Available
> issues from these series will be listed in the next CAMASE_NEWS.
> The group further provides teaching programs, computer aided
> instructions, PhD and MSc programs in Crop and Plant Sciences, and
> other training programs in The Netherlands and abroad. For further
> information, contact dr. Frits Penning de Vries at AB-DLO
> (P.O.Box 14, 6700 AA, Wageningen), dr. Peter Leffelaar at PE-WAU
> (P.O.Box 430, 6700 AK Wageningen), or dr. Aad van Wijk at SC-DLO
> (P.O. Box 125, 6700 AC, Wageningen).
>
> Over 50 scientists collaborate in Wageningen in an informal
> simulation group on a range of topics. They use many different
> models, many of which stem from a common base.
> Current activities of AB-DLO and PE-WAU address production and
> environmental issues in natural and agricultural ecosystems at
> integration levels with time coefficients of hours (plants,
> pests), days (soils, crops) and years (production systems). The
> research is to improve understanding of systems, but also leads to
> designing of improved systems and their optimization. Activities
> include the development, testing and documentation of:
> - standard modules for crop, soil and pest modelling;
> - a 'simulation environment' or 'shell' for use with the standard
> modules per se and in cropping systems research, plus user
> friendly documentation;
> - a method for in-depth analysis of the inherent accuracy of crop
> modelling, and consequences of parameter uncertainty;
> - more computer aided instructions programs on systems analysis and
> crop modelling, and other training materials for use at MSc, PhD
> and post doc levels;
> - simulation models of competition between plants (and trees) for
> the capture of the essential resources for plant growth (i.e.
> light, water and nutrients).
> The research SC-DLO focuses on problems of physical planning,
> environmental protection and water management in rural areas to
> support well-balanced decision making. Agro-ecosystem modelling
> activities are on:
> - transport of water and substances (nutrients and pesticides) in
> soils;
> - soil-water-plant-atmosphere relationships;
> - regional modelling: unsaturated zone models linking regional
> ground and surface water models.
> The scale of model application ranges from field to regional
> level. Fields of application are land evaluation (crops, pasture,
> forestry); water management (interactions agriculture-nature-
> ground water resources, drainage, irrigation); soil protection/
> environmental impact studies (soil acidification, emissions of
> nutrients and pesticides to ground and surface waters); scenario
> studies for rural land use and environmental problems.
>
> Many of the Wageningen models were written in the simulation
> language CSMP, and later PCSMP for PC's. Most models are now
> produced in FORTRAN, within a framework called FSE ( the FORTRAN
> Simulation Environment) that ensures standardization and
> compatibility. A translator has been developed to translate simple
> CSMP models into modules for FSE, so that the advantages for
> teaching of a real simulation language are retained. This
> standardization of models and modelling approaches is expected to
> continue.
> Interesting developments occur in the field of linear programming.
> LP-models exist to optimize production of milk, tulip bulbs (how
> very Dutch!) and arable crops on farms. It is also being applied
> to optimization of land use in developing countries, and the
> European Community. An essential feature of the method is that
> consequences of conflicting goals, such as maximizing crop
> production and minimizing NH3-loss and pesticide use, can be
> compared objectively. The method is referred to as 'multiple goal
> linear programming', and helps to quantify options for integrated
> agricultural production.
>
> Another important line of research aims to couple Geographic
> Information Systems with crop and soil models. While this is
> proceeding quite well at a technical level, there are important
> issues of aggregation, spatial heterogeneity and data scarcity
> that require careful analysis.
>
>
> ====================================================================
> CAMASE: A CONCERTED ACTION FOR THE DEVELOPMENT AND TESTING OF
> QUANTITATIVE METHODS FOR RESEARCH ON AGRICULTURAL SYSTEMS AND THE
> ENVIRONMENT.
>
> The objectives of CAMASE are to advance quantitative research on
> agricultural systems and their environment in the EU-countries, by
> improving systems research in participating institutes through
> exchange and standardization of concepts, approaches, knowledge,
> computer programs and data.
> CAMASE relates to a small network of research groups, and a broad
> group of scientists receiving information. The network consists of
> scientists from five groups in Europe: Denmark (Royal Veterinary
> and Agricultural University, Copenhagen), France (Institute
> Nationale de la Recherche Agronomique, Toulouse), Spain (Cordoba
> University, Cordoba), Scotland (Institute of Ecology and Resource
> Management, Edinburgh) and The Netherlands (AB-DLO , TPE-WAU and
> SC-DLO, Wageningen).
>
> With CAMASE_NEWS, we aim to improve communication among scientists
> working in agro-ecosystem modelling and interested in better
> access to appropriate models, data, and related tools, instruction
> materials. CAMASE-core groups and others can contribute
> spontaneously or will be invited to contribute. Responsibility for
> the opinions expressed rests with the authors.
>
> CAMASE_NEWS will appear four times per year. Please submit news
> items for CAMASE_NEWS and requests for new subscriptions to:
>
> F.W.T. Penning de Vries/M.C. Plentinger
> DLO-Research Institute for Agrobiology and Soil Fertility (AB-DLO)
> P.O.Box 14
> 6700 AA WAGENINGEN
> The Netherlands
> Telephone: +31.8370.75961
> Telefax: +31.8370.23110
> Internet: camase@ab.agro.nl
>
> ====================================================================
>
>
> ----- End forwarded message
>
>
>
> ------------------------------
> End of Digest
> ************************
>

I received the following message today, so I thought I'd send the reply to
the group as a whole, as it will arouse more discussion that way:

>I work also work with weeds. I have been doing some work with weed
>competition and population dynamics. Please tell me more of your work
>with weeds.

> Milt McGiffen
> Dept. Botany and Plant Sciences
> Univ. California
> Riverside, CA

The weed element in PARCH (model described yesterday) is in its infancy at
present, but mainly because it is lacking validation data. I was using
PARCH to analyse some water harvesting experiments from Botswana (Southern
Africa) on which maize was growing, so I was modelling drainage,
evaporation, storage and transpiration. When the sums did not add up
properly, I studied the experimental records and found that weed cover of
up to 40% had been recorded as an afterthought in the margin. I built a
simple module which allowed weeds to grow, with a similar water use
efficiency to the crop, and found that they were probably using around 30%
of the water available to the crop (not a trivial amount, as the footnote
would have suggested). Lacking further data, I made the weed module into a
usable element with menu driven parameters, and have since awaited an
opportunity to improve it.

Although it will be quite easy for PARCH to model the actual growth (from
resource capture) of the weeds, that would require complex definitions of
the weed morphology, which was not justified by my sketchy data. Instead, I
have adopted the approach where the user defines two weed types; one pre-
planting (usually large and well established), and the other which
establishes after the tillage of planting, and directly competes with the
crop. Competition at present is only for water; it is assumed that the
maize or sorghum is taller than the weed - this is open to improvement.

In practice, this is controlled by 7 menu parameters:
Weed root uptake rate - related to weed density & morphology.
Fractional Light Interception pre-tillage - water use proportional to light.
Rooting Depth pre-tillage - defines zone of competition for water.
Fractional Light Interception after regrowth.
Rooting Depth after regrowth.
Start date of weed re-establishment.
Date of full re-establishment.

These parameters are simple, and force a weed to grow in the way observed
in the experiment. Only water availability alters the weed morphology at
present.

I would be interested to improve the competition element of the crop on the
weed (the weed can already severely reduce establishment and growth of the
crop in the model), if data were available. I feel that in the semi-arid
regions I am working with, light levels are usually adequate for all but
the densest canopies, and water (and nutrient) competition will prove to be
the most limiting factors.

I look forward to hearing from Milt and anyone else who is interested in
working on / discussing this topic.

Yours,

Rick Bradley
==== =======
+------------------------------------------------------------------+
| R.G.Bradley, Biometry, | Tel. 0602 516317 |
| Dept. of Environmental Science, | |
| University of Nottingham, | Fax. 0602 516261 |
| Sutton Bonington Campus, | |
| LEICS. LE12 5RD, UK | Email SBZRB@sbn2.nott.ac.uk |
+----------------------------P--A--R--C--H-------------------------+

Does anyone know if the Parnas, 1975, Soil Biology and
Bichemistry, Vol. 7, pp. 161-169, model has been validated or
applied. We are currently using the Kafkafi, Haddas, and Bar-Yosef
model in the GOSSYM cotton model but are interested in more
mechanistic models of processes.

James McKinion

In Message Wed, 13 Apr 1994 05:39:43 -0500,
"Rick Bradley - Env. Sci. " <SBZRB@sbn2.phes.nottingham.ac.uk> writes:

>I received the following message today, so I thought I'd send the reply to
>the group as a whole, as it will arouse more discussion that way:
>
>>I work also work with weeds. I have been doing some work with weed
>>competition and population dynamics. Please tell me more of your work
>>with weeds.
>
>> Milt McGiffen
>> Dept. Botany and Plant Sciences
>> Univ. California
>> Riverside, CA
>
>The weed element in PARCH (model described yesterday) is in its infancy at
>present, but mainly because it is lacking validation data. I was using
>PARCH to analyse some water harvesting experiments from Botswana (Southern
>Africa) on which maize was growing, so I was modelling drainage,
>evaporation, storage and transpiration. When the sums did not add up
>properly, I studied the experimental records and found that weed cover of
>up to 40% had been recorded as an afterthought in the margin. I built a
>simple module which allowed weeds to grow, with a similar water use
>efficiency to the crop, and found that they were probably using around 30%
>of the water available to the crop (not a trivial amount, as the footnote
>would have suggested). Lacking further data, I made the weed module into a
>usable element with menu driven parameters, and have since awaited an
>opportunity to improve it.
>
>Although it will be quite easy for PARCH to model the actual growth (from
>resource capture) of the weeds, that would require complex definitions of
>the weed morphology, which was not justified by my sketchy data. Instead, I
>have adopted the approach where the user defines two weed types; one pre-
>planting (usually large and well established), and the other which
>establishes after the tillage of planting, and directly competes with the
>crop. Competition at present is only for water; it is assumed that the
>maize or sorghum is taller than the weed - this is open to improvement.
>
>In practice, this is controlled by 7 menu parameters:
>Weed root uptake rate - related to weed density & morphology.
>Fractional Light Interception pre-tillage - water use proportional to light.
>Rooting Depth pre-tillage - defines zone of competition for water.
>Fractional Light Interception after regrowth.
>Rooting Depth after regrowth.
>Start date of weed re-establishment.
>Date of full re-establishment.
>
>These parameters are simple, and force a weed to grow in the way observed
>in the experiment. Only water availability alters the weed morphology at
>present.
>
>I would be interested to improve the competition element of the crop on the
>weed (the weed can already severely reduce establishment and growth of the
>crop in the model), if data were available. I feel that in the semi-arid
>regions I am working with, light levels are usually adequate for all but
>the densest canopies, and water (and nutrient) competition will prove to be
>the most limiting factors.
>
>I look forward to hearing from Milt and anyone else who is interested in
>working on / discussing this topic.
>
>Yours,
>
> Rick Bradley
> ==== =======
> +------------------------------------------------------------------+
> | R.G.Bradley, Biometry, | Tel. 0602 516317 |
> | Dept. of Environmental Science, | |
> | University of Nottingham, | Fax. 0602 516261 |
> | Sutton Bonington Campus, | |
> | LEICS. LE12 5RD, UK | Email SBZRB@sbn2.nott.ac.uk |
> +----------------------------P--A--R--C--H-------------------------+

I think I can help with at least some of your interest in weed models. As
you probably know, the people from Wageningen in the Netherlands have
published a series of papers and books on weed models -- C.J.T. Spitters and
Martin Kropff especially. As to data, I have collected a lot of literature
on weed data similar to what I think you need. I also have my own
experimental data, which I continue to collect. If you could give me a
better idea of what you need -- say send over an example with real numbers
and parameters and maybe how you derived the parameters -- I'll take a look
and send you back what seems to fit.

We are currently doing an experiment that looks at competition for light in
several tomato varieties and velvetleaf and purslane. I may even be
able/willing to collect some data just for your purposes -- let me know
what you can use.

---
University of California
Riverside, CA 92521

Dear Subscribers,

For your information

>
> The March archive for your list is now available.
>
Jerome Pier
List Owner
jp@unl.edu

Hello,
My name is Paul and I am a postgraduate student at
Monash University, Victoria, Australia. At present I am
affiliated with the Cooperative Research Centre for
Catchment Hydrology, in the programme of catchment salt
and water balance. One of the main tasks in this
programme is to increase understanding and modelling
techniques for catchment salt and water processes,
particularly in relation to salinisation of land and streams.
My work centres on measurement and modelling of
water-solute processes underlying Eucalypt plantations
in an area of shallow water tables (about 2m from the land
surface). I am attempting to locate a suitable existing model
to use which should include the affect of saline water on
trees and density/solute dependent flow characteristics.

The particular plantation in question is 18 years of age and
2.5ha in size in an irrigation area in Northern Victoria (south
east Australia), however, the plantation itself is not irrigated.
The aim of the project is to describe and attempt to quantify
the water-solute processes occurring under the plantation.
The effect of density dependent flow should not be ignored.
Monitoring to date has indicated a local reduction in water
table levels under the plantation with increased salt
concentrations. Outside the plantation the piezometric
surface is lower than the water table yet under the
plantation, the piezometric surface is higher than the water
table, causing an upward gradient of waterand solute
movement under the plantation. The big question is will salt
concentrations under the plantation affect the growth, water
use and sustainability of the trees? If so, when? and is
sustainability possible in conjunction with
drainage/pumping techniques to remove and leach salts
present in the root zone?

My background is in agricultural science and am currently
completing a masters degree in hydrogeology. My interest
in salinisation of land and water developed while studying
agriculture and I have studied groundwater processes to
increase my knowledge in this area. The use of trees to
control salinity has been more widely adopted in dryland
areas in an attempt to reduce recharge to groundwater. In
irrigation areas, however, the shallow and often saline water
tables have precluded use of trees and control there has
relied on engineering options. My work is part of a project to
look into the feasibility of growing hardwood (Eucalypt)
plantations in irrigation areas in an attempt to lower
groundwater levels while maintaining growth and
subsequent hardwood production. Little work has been done
due to the notion that trees will not grow well in areas
of shallow and saline water tables. Any information on
relevant work done in this area would be appreciated. Hope
to hear from you regarding suitable models to use in this
area.

Paul

Tom,

Any success on your efforts to adjust the N mineralization
in your potato model?

<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>
| MIKE MUNSTER |
<> EMAP-Agroecosystems phone 919-515-3311 <>
| 1509 Varsity Dr. fax 919-515-3593 |
<> Raleigh, NC 27606 email mike_munster@ncsu.edu <>
| USA |
<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>

Hi Mike, not much. I lowered the minimum temperature from 5 to -8
and increased the volatile portion of crop residue from 10% to 50%
but that didn't help enough. Tom

Tom Hodges Cropping Systems Modeler ___ ___
USDA-ARS / \_/ \
Rt. 2, Box 2953-A Telephone: 509-786-2226 | |
Prosser, WA 99350 \______/^\/
USA potato tuber
thodges@beta.tricity.wsu.edu
=====================================================================
...photosynthesis makes the world go around... Mr. Potato Head

On Tue, 19 Apr 1994 mike@arrc.ncsu.edu (Mike Munster) wrote
> Subject: Re: Simulating soil N transformations
>
> Tom,
>
> Any success on your efforts to adjust the N mineralization
> in your potato model?
>
> <>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>
> | MIKE MUNSTER |
> <> EMAP-Agroecosystems phone 919-515-3311 <>
> | 1509 Varsity Dr. fax 919-515-3593 |
> <> Raleigh, NC 27606 email mike_munster@ncsu.edu <>
> | USA |
> <>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>-<>
>
>
>
> ------------------------------
> End of Digest
> ************************
>

Hallo,
My name is Alex Gimona, and I have recentely subscribed to this list, so my
apologies if this message is misplaced.
I am a PhD student in Aberdeen University, working on relationships between
crops and birds.
I wonder if anyone knows of any models (and input data needed) simulating the growth of of winter and spring
cereals, in particular barley and wheat.
I am trying to work out in which stage of growth were the crops in areas where
bird field data were collected. I have daily data collected from nearby
meteorological stations.
Any help would be much appreciated.
Thanks a lot
A. Gimona (geo293@aberdeen.ac.uk)

Dear Subscribers,

Well my mailbox is filling to the point where I can lo
longer ignore it with bounced messages. The following persons are
about to be unsubscribed from the list as thier addresses are
incorrect. Please let me know as soon as possible if there is
some way around this drastic measure. Otherwise, you are outta
there...

Wesley Rosenthal Rosenw@apsrusg.sth.dpi.qld.gov.au
Harbans Lal lal@splash.cor1.epa.gov
Larry Turner chico.aen.uky.edu@aen.uky.edu
Yimei Guo yguo@corpus-ctr.tamu.edu
Bruce Heimbigner bruce@heimbig.ansci.wsu.edu

I might suggest that you try unsubscribing and resubscribing from
the list and see if that helps. It may be an old wives tale but
it works sometimes.

Sincerely,

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

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From: geo293@aberdeen.ac.uk
To: Multiple recipients of list <agmodels-l@unl.edu>
Subject: looking for a cereals growth model

Hallo,
My name is Alex Gimona, and I have recentely subscribed to this list, so my
apologies if this message is misplaced.
I am a PhD student in Aberdeen University, working on relationships between
crops and birds.
I wonder if anyone knows of any models (and input data needed) simulating the
gro wth of of winter and spring
cereals, in particular barley and wheat.
I am trying to work out in which stage of growth were the crops in areas where
bird field data were collected. I have daily data collected from nearby
meteorological stations.
Any help would be much appreciated.
Thanks a lot
A. Gimona (geo293@aberdeen.ac.uk)

We have used the CERES Wheat model fairly extensively with reasonably good
results. It is a moderately detailed growth and phenology model. The phenology
model is completely temperature driven and can be (with some work) decoupled
from the growth model. A much simpler phenology model is PLANTTEMP, written by
the ARS group (Ron Rickman and Betty Klepper) at Pendleton, OR and available
from Oregon State University.

John Bolte

Hello,

My name is Howard Clyma. I am a Ph.D. graduate student working on
irrigation scheduling and nitrate leaching. I am looking for a good
nitrate leaching model under corn. A model that tries to account for
corn nitrogen use and soil microbial activity might be helpful instead.
I would appreciate any comments or suggestions.

Sincerely,

Howard
-----------------------------------------------------------
Howard Clyma |Office:(402)472-6340
Graduate Fellow |Home:(402)435-3494
Dept. of Biological Systems |Fax::(402)472-6338
Engineering |Internet:
154 L.W. Chase Hall, East Campus |hclyma@engec.unl.edu
University of Nebraska-Lincoln |Bitnet:
Lincoln, NE 68583-0726 |bsen057@unlvm.unl.edu
-----------------------------------------------------------

Hi Howard,
CERES-Maize, RZWQM, EPIC, NLEAP for starters all do some of what you are
asking for. I think the first two have more mechanistic corn growth
models. RZWQM is probably most demanding in terms of initial soils data
but has the most mechanistic soils processes and has had the least
testing. CERES-Maize is pretty easy to use. I haven't used EPIC or
NLEAP. Tom

Tom Hodges Cropping Systems Modeler ___ ___
USDA-ARS / \_/ \
Rt. 2, Box 2953-A Telephone: 509-786-2226 | |
Prosser, WA 99350 Fax: 509-786-4635 \______/^\/
USA potato tuber
============= thodges@beta.tricity.wsu.edu ========================
...photosynthesis makes the world go around... Mr. Potato Head

On Sat, 23 Apr 1994 agmodels-l@unl.edu wrote:

> From: hclyma@engecs1.unl.edu (Howard Clyma)
> Subject: Looking For Nitrate Leaching Models
> My name is Howard Clyma. I am a Ph.D. graduate student working on
> irrigation scheduling and nitrate leaching. I am looking for a good
> nitrate leaching model under corn. A model that tries to account for
> corn nitrogen use and soil microbial activity might be helpful instead.
> I would appreciate any comments or suggestions.
> Howard Clyma |Office:(402)472-6340
> 154 L.W. Chase Hall, East Campus |hclyma@engec.unl.edu

RE>AGMODELS-L digest 85
26/4/94 8:43
G'day Alex Gimona,
Cereal models.
Here are a few for wheat
AFRC - Wheat Model contact Bristol Uni
O'Leary's Wheat Model see Ag Systems 1985
- working on a new version
Stapper's model - contact CSIRO Canberra
Handoko's model - contact Uni. of Melb.
MUSIM-Wheat/N - contact Uni. of Melb.
CERES-Wheat - contact Prof. Ritchie Michigan SU
Sinclair and Amir - contact Florida SU, Gainesville
Loomis and Amthor - UC Davis - in progress
Van Keulen & Seligman - Wageningen
TAMW - Steve Maas
Also interesting MSc Theses - Macquarie Uni
Zvi Hochman
Jim Morgan
Literally hundreds of them out there.
Cheers,
Glyn

Howard Clyma wrote, "I am looking for a good nitrate leaching model
under corn,"
and Tom Hodges answered, "CERES-Maize, RZWQM, EPIC, NLEAP for starters
all do some of what you are asking for."

I wonder if any of these models can be used as a Soil Chemistry lab exercise.
The Division S-2 of the Soil Sci. Soc. of Am. (SSSA) has asked Tsutomu Ohno
to chair a committee that will put together a Laboratory Manual for a
graduate Soil Chemistry course. I think that some students would learn a
great deal from a simulated experiment; perhaps more than in a rushed,
time limited, real field data-collection experiment. Are there any
suggestions or thoughts on this subject out there? I'd like to give it a try
for my Fall 1994 undergraduate class (my graduate level Soil Chemistry class
does not have a lab section --- it's a matter of opinion, perhaps, but to me
most lab experiments should be restricted to undergraduate credits). Any
assistance is welcomed. For starters, how do I get these models?

Cristian Schulthess

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

I would like to unsubscribe. Thank you.

simpotato is available at ftp.tricity.wsu.edu in the directory
pub/simpotato or at least it was last time I checked. Tom Hodges
thodges@beta.tricity.wsu.edu

> From: "Cristian Schulthess " <CSCHULTH@canr1.cag.uconn.edu>
> Subject: Leaching Models for the Classrooms
>
> Howard Clyma wrote, "I am looking for a good nitrate leaching model
> under corn,"
> and Tom Hodges answered, "CERES-Maize, RZWQM, EPIC, NLEAP for starters
> all do some of what you are asking for."
>
> I wonder if any of these models can be used as a Soil Chemistry lab exercise.
> The Division S-2 of the Soil Sci. Soc. of Am. (SSSA) has asked Tsutomu Ohno
> to chair a committee that will put together a Laboratory Manual for a
> graduate Soil Chemistry course. I think that some students would learn a
> great deal from a simulated experiment; perhaps more than in a rushed,
> time limited, real field data-collection experiment. Are there any
> suggestions or thoughts on this subject out there? I'd like to give it a try
> for my Fall 1994 undergraduate class (my graduate level Soil Chemistry class
> does not have a lab section --- it's a matter of opinion, perhaps, but to me
> most lab experiments should be restricted to undergraduate credits). Any
> assistance is welcomed. For starters, how do I get these models?

I try to incorporate frost damage into crop modeling to predict grain
yield. Does anyone have the knowledge to quantify yield reduction due to
fall frost damage?

Thanks!

*---*
Chingpin Tung
ct16@cornell.edu
------------------------------ Cut here ------------------------------