AGMODELS-L: 199710XX

is the compilation of discussion during Oct 97

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Date: Wed, 01 Oct 1997 00:03:24 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 29 Sep 1997 to 30 Sep 1997
Date: Wed, 1 Oct 1997 00:03:24 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 29 Sep 1997 to 30 Sep 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There are 3 messages totalling 280 lines in this issue. Topics of the day: 1. The history of ag modeling. 2. The history of ag modeling... Thank you John. 3. Key developments
Date: Tue, 30 Sep 1997 14:36:07 -0500 From: "E. John Sadler" (sadler@SUNBRN.FLORENCE.ARS.USDA.GOV) Subject: The history of ag modeling. Greetings, After the quick note the other day about historical references in ag modeling, I read over the dissertation again and concluded that several events and lines of work merited expansion beyond the paragraph in the earlier e-mail. The following is the particular section of the dissertation, re-scanned today (I couldn't find the old CP/M disks!). It is about 10k long. The references are about 33k long, and I can only send them as an attachment. Therefore, I will send them only to those who request it. EJ Sadler 1983. Simulation of the energy, carbon, and water balance of a fluid-roof greenhouse. Texas A&M University, PhD Dissertation, pg 18-24. Crop Models There are many models of crop growth, ranging from the fairly simple to the extremely complex. Unfortunately, there is a scarcity of reviews of the subject in recent years. The review of Loomis and Williams (1969), and the collection of papers from the International Biological Programme (IBP/PP) technical meeting in Trebon, Czechoslovakia, in 1969, provided a comprehensive view of the discipline at that time. A brief review by Hesketh and Jones (1976) covers the modeling of cotton. Thornley (1976) covered the subject of modeling and reviewed some models in his book. Hildreth (1976) covered several of the better-known crop models. To organize the existing models for a logical discussion, the classification of Hildreth (1976) was adopted: a) plant function models, b) crop growth and yield models, and c) crop development and yield models. If physical principles are simulated throughout, the degree of complexity generally increases from a) to c). The plant function models concern instantaneous processes. The crop growth and yield models integrate the plant function models at the plant or plant community scale over short time periods. The development models extend the growth models over the growing season, including simulation of physiological events such as flowering and maturity. There do exist crop growth and crop development models that start with empirical observations and that are more simple than the integrated process type. Simulation objectives of the plant function models include radiation interception, photosynthesis rate, respiration rate, translocation or carbohydrate partitioning, leaf energy balance, transpiration rate, and root water uptake. An extensive review of light interception models was given by Lemeur and Blad (1974). Since then, analyses have been made by Sinclair and Lemon (1974), Anderson and Miller (1974), Norman and Jarvis (1974, 1975), Mann et al. (1977), Kimes et al. (1980), Denholm (1981a, 1981b), Oker-Blom and Kellomaki (1982), and Sinclair and Knoerr (1982). Models of photosynthesis have been reported by Chartier (1970), Lommen et al. (1971), Van Bavel (1975), Tenhunen et al. (1976a, 1976b), Enoch and Sacks (1978), and Thornley et al. (1981), with a review by Thornley (1976). Respiration has been modeled by McCree (1970, 1974), Penning de Vries (1972, 1974, 1975), Penning de Vries et al. (1974), Thornley (1976, 1977), Gay (1981), Thornley et al. (1981), and others. For a review and analysis, see Gay (1981). Leaf energy balance was simulated by Gates (1968) and Van Bavel et al. (1973), among others. Models of crop evapotranspiration abound. Thornthwaite (1948), Penman (1948), Blaney and Criddle (1962), Jensen and Haise (1963), Monteith (1965a), and Van Bavel (1966) are examples. A comprehensive comparison of water use models was made for a volume edited by Jensen (1973). Much work has been done on root water uptake, with Lascano (1982) giving an extensive, recent review. In the third category, there exist two major classifications of models, based on the method of simulation. The first is the multiple regression or other statistical method of empirical modeling of crop yield, development, or status, based on environmental variables, usually temperature and rainfall. These will not be further discussed. The second integrates the plant functions in some manner, summing the individual effects to result in growth or yield. A historical perspective of the evolution of crop simulation models is useful. One of the earlier works was by Monsi and Saeki (1953) and Kasanaga and Monsi (1954), who studied the importance of light in dry matter production, and introduced the idea of dividing the canopy into layers. Monteith (1965b), De Wit (1965) and Duncan et al. (1967) reported models of photosynthesis that were based on interception of radiation only, and not on temperature or CO2 concentration. Stewart and Lemon (1969) used the light interception models of Duncan et al. (1967) and De Wit (1965) in the Soil-Plant-Atmosphere Model (SPAM), which considered the microclimate in each layer of a canopy. The work cited above was known at the time of the IBP/PP technical meeting in Trebon, Czechoslovakia. In that meeting, several papers of note were given. De Wit et al. (1970) described the Elementary Crop Simulator ELCROS. Ross (1970), Anderson (1970), and Kuroiwa (1970) reviewed light interception and photosynthesis models. Acock et al. (1970) discussed spatial variability of light in the canopy. Tooming (1970) discussed net photosynthesis and plant adaptation. Monsi and Murata (1970) discussed dry matter distribution in crops. Denmead (1970) and Uchijima (1970) both discussed simulations of transfer processes within canopies. Also, the paper of McCree (1970), listed earlier, was given. After the Trebon meeting, the work started in the Netherlands by De Wit (1965) and De Wit et al. (1970) continued. Goudriaan and Waggoner (1972) described an early version of a model updated and described fully by Goudriaan (1977), and tested by Stigter et al. (1977). The model BACROS, for Basic Crop Simulator, evolved (De Wit et al., 1978). A third model simulated field water use and crop yield (Feddes et al., 1978). In the United States, Chen et al. (1969) started work that evolved into the Nebraska corn model (Splinter, 1973; Splinter, 1974; Childs et al., 1977). A group in Arizona developed a cotton model (Stapleton and Meyers, 1971; Stapleton et al., 1973). In Ohio, Curry (1971) and Curry and Chen (1971) described a dynamic model of plant growth, and Curry et al. (1975) described the soybean growth model SOYMOD I, which was used by Meyer et al. (1981) to simulate reproductive processes and senescence. At Purdue University in Indiana, Miles et al. (1973) and Holt et.al. (1975) developed a model of alfalfa, SIMED. In Texas, Arkin et al. (1976) and Maas and Arkin (1978) described a simulation model of grain sorghum, SORGF. Other models developed in the 1970's include the CORNMOD model of Baker and Horrocks (1974), the model of Phragmites communis reported by Ondok and Gloser (1978a, 1978b), the barley model of Kallis and Tooming (1974), the shortgrass prairie model of Conner et al. (1974), the wheat model of Milthorpe and Moorby (1974), the tobacco model of Wann et al. (1978), and corn model of Russo and Knapp (1976). The descendants of the Duncan et al. (1967) model will now be examined. Three partial tests of their model were reported (Loomis et al., 1968; Williams et al., 1968; and Loomis and Williams, 1969), and an independent test was reported by Keener (1972) and Keener and McCree (1975). Duncan (1971) studied crop architecture and its influence on canopy photosynthesis using the 1967 model, and included a CO2 transport routine to study the vertical profiles of CO2 within a canopy (Duncan and Barfield, 1970, 1971). Duncan also collaborated with the group at Mississippi State University to create SIMCOT and related models of cotton (Hesketh et al., 1971, 1972; Baker et al., 1972). The SIMCOT model series was further documented by Jones et al. (1974), and McKinion et al. (1975), who included the nitrogen balance of the cotton crop. Duncan's coauthors in the 1967 paper developed a model of sugar beet growth, SUBGOL (Fick et al., 1975; Loomis and Ng, 1977; Hunt and Loomis, 1979). Meanwhile, SPAM (Stewart and Lemon, 1969). itself partially based on the 1967 model and also De Wit (1965), was generating excitement in modeling. The initial journal article (Lemon et al., 1971) showed many researchers the potential for modeling the microclimate within crops. Lemon et al. (1973) studied evapotranspiration with SPAM. Shawcroft et al. (1974) described SPAM and a sensitivity analysis. Van Bavel (1974) used part of SPAM and the leaf action model of Van Bavel et al. (1973) to create CANLAM and study the behavior of sunflowers with respect to soil water potential. This combination of SPAM and the leaf action model was used in an optimization study of water use efficiency (Ahmed, 1974; Ahmed et al., 1976). The CO2 assimilation equations of Van Bavel (1975) were incorporated into their model, then named CANLAM2. This was used in simulations of the efficiency of field CO2 enrichment by Takami (1974) and Takami and Van Bavel (1975), and in investigations of the effect of respiration on crop production by McCree and Van Bavel (1977). Takami and Kumashiro (1982) used CANLAM2 to study the effect of canopy architecture on rice photosynthesis. In unrelated work, Sinclair et al. (1977) compared the original SPAM, a simplified version of SPAM, and a "big leaf" model similar to that of Monteith (1965b). Conclusion of Literature Review For the purpose of satisfying the objectives of this thesis, the SG79 greenhouse energy balance model of Van Bavel and Sadler (1979b), and the CANLAM2 model of Takami and Van Bavel (1975) and of McCree and Van Bavel (1977) were selected. The choice of SG79 was simple: it was the only model that considered the energy, water, and CO2 balance of the greenhouse together. Of the crop models, the CANLAM2 model was chosen, in spite of its complexity relative to SG79, because the inputs and outputs were compatible with those in SG79's crop calculation section. In addition, the modification of the code, which was in machine storage here, was more simple than either obtaining another model and modifying it, entering a model from a listing, or building one from the start. ============================================================== E. John Sadler, Ph.D. USDA-ARS sadler@florence.ars.usda.gov Coastal Plains Soil, Water, and Plant Research Center 803-669-5203x112 (voice) 2611 West Lucas St. 803-669-6970 (fax) Florence, SC 29501-1241 U.S.A. ==============================================================
Date: Tue, 30 Sep 1997 14:39:31 -0500 From: "Robert M. Caldwell" (serc018@UNLVM.UNL.EDU) Subject: Re: The history of ag modeling... Thank you John. Dear John Sadler, and other list members, Thank you for sending the literature review on early model development. You have referenced some great literature. Anyone have opinions on the key technology developments that helped drive those early modeling activities? The availability of CSMP on IBM mainframes is one, given the importance of the language to the early research. What were some others? Note also the importance of the International Biological Programme (IBP). Any other projects or groups that should be mentioned? Sincerely, Bob Caldwell, Cropping Systems Specialist, Dept. of Agronomy/SEREC/NEREC University of Nebraska - Lincoln 204 Mussehl Hall, P.O. Box 830714, Lincoln, NE 68583-0714 serc018@unlvm.unl.edu Phone: (402) 472-3674. FAX: (402) 472-3858.
Date: Tue, 30 Sep 1997 16:28:30 -0500 From: "E. John Sadler" (sadler@SUNBRN.FLORENCE.ARS.USDA.GOV) Subject: Key developments Greetings to the list, Key developments should certainly include CSMP, as a lot of the early 70's work used it, especially de Wit's group at Wageningen. The PUDOC publication lists are very useful, as are several dissertations published there. Developments in the 80's would be the migration of simulations from mainframes to PCs. A simulation now can be done faster than the CPU time usage on the 1980-vintage mainframe, to say less of the clock-on-the-wall time. The majority of the earlier models were in FORTRAN or CSMP; what are the current versions written in? Most distributed software is compiled for the PC, so development software is not such a big issue, which may be important enough to mention. Integration into specialized database managers such as decision support systems, GIS, and others (Cite Caldwell's symposium at ASA this year) is becoming important. The groups working in the 70's should include Duncan's, Lemon's, Stapleton's, Curry's, Jones', and van Bavel's (and probably others) in the USA. The 80's saw Ritchie, Hanks, Don Baker, Ken Boote, and others, with the CERES/DSSAT suite, Gossym, Glycim, and some others resulting. Groups active in the 90's should be available from Robert Caldwell and MC Fortin or from Gerrit Hoogenboom after the two related symposia at the Amer. Soc. Agron meetings at Anaheim. Perhaps they would fill these in, to provide a start to current work. My summary earlier today was clearly directed toward the solution needed for my dissertation work. There are likely some groups and citations missed. If anyone is seriously interested in compiling a history, ask this vast and unpaid reseearch group (this list) for the things missing from it. Bob, have there been responses to your request that went directly to you and not via this list? If so, could you summarize and distribute? Thanks John ============================================================== E. John Sadler, Ph.D. USDA-ARS sadler@florence.ars.usda.gov Coastal Plains Soil, Water, and Plant Research Center 803-669-5203x112 (voice) 2611 West Lucas St. 803-669-6970 (fax) Florence, SC 29501-1241 U.S.A. ==============================================================
Date: Fri, 03 Oct 1997 03:49:35 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 30 Sep 1997 to 2 Oct 1997
Date: Fri, 3 Oct 1997 03:49:35 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 30 Sep 1997 to 2 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There are 3 messages totalling 114 lines in this issue. Topics of the day: 1. More on history 2. available for long/short term projects 3. Modelling History
Date: Wed, 1 Oct 1997 17:21:00 -0700 From: "Vera, Raul (3363)" (R.VERA@CGNET.COM) Subject: More on history Let me add my 5 cents worth. In my view, some important early references to modelling and simulation are as follows: Naylor,TH (1966): Computer Simulation Techniques, London:Wiley. Van Dyne,GM (1966): Application and integration of multiple linear regrtession and linear programming in renewable resource analyses. Journal of Range Management 19, 356-362. Duncan,WG et al. (1967): A model for simulating photosynthesis in plant communities. Hilgardia 38, 181-205. von Bertalanffy,L (1968): General system theory. Foundations, development, applications. G. Braziller, New York. Maslow,AH (1971): The farther reaches of human nature. Penguin, New York. Arcus,PL (1963): An introduction to the use of simulation in the study of grazing management problems. Proceedings of the New Zealand Society of Animal Production. 23, 159-168.
Date: Wed, 1 Oct 1997 21:16:57 -0700 From: Tom Hodges (thodges@TRICITY.WSU.EDU) Subject: available for long/short term projects My position with the USDA-ARS is now ended so I am looking at other opportunities. I am available to help with various sorts of short or long term projects until I find other long term employment (or possibly decide to stay with free-lancing). I can contribute to model application and development projects, data analysis, experiment design, web page development, new crop evaluation, irrigation and fertility assessment, etc. More details are available thru my web page. Tom Tom Hodges, Cropping Systems Modeler 3030 W 4th Ave, #27 Kennewick, WA 99336 USA email: thodges@tricity.wsu.edu voice: 509-786-9207, 509-783-3792 Fax: 509-786-9370, 509-786-9277 HomePage http://www.tricity.wsu.edu/htmls/hodges
Date: Thu, 2 Oct 1997 10:09:03 +0200 From: Abraham Singels (singels@AQUA.CCWR.AC.ZA) Subject: Modelling History Hallo Agmodellers Modelling effort in South Africa A lot of work has been done by the Department of Agrometeorology, University of the Free State led by Jimmy de Jager since 1976. The effort started with the maize crop. A lot of effort was put into the water balance. Models are applied for irrigation management, crop forecasting, drought monitoring and production risk assessment. Workers from several institutions over South Africa supplied data and expertise for the development and validation of these models. The PUTU family of models consists of models for maize, wheat, natural grassland and a generic water balance model and is housed in a Windows-based shell. The models are written in Basic. When I started (1981) we had a Hewlett Packard desk top with 64k RAM and a tape reader. We started in Msbasic and "progressed" to QuickBasic. Unfortunately not all of the developments were published in English. Here are two references: 1) Singels, A. and De Jager, J.M., 1991. Refinement and validation of the PUTU wheat crop growth model. 1. Phenology. S.A. J. Plant and Soil 8: 59-66 2) Singels, A. and De Jager, J.M., 1991. Determination of optimum wheat cultivar characteristics using a growth model. Agric. Systems 37: 25-38 For more details and references contact Jimmy de Jager at Jimmy@landbou.uovs.ac.za Geoff Inman-Bamber developed the Canegro model based on Ceres - Maize. This model is currently included in the Dssat package. We are continuing with the Canegro modelling effort at S.A. Sugar Ass. Experiment Station. 1) Inman-Bamber, N.G., 1991 A growth model for sugarcane based on a simple carbon balance and the Ceres-Maize water balance. S.A. J. Plant and Soil 8: 93-99. (Geoff.Inman-Bamber@tag.csiro.au) Regards Abraham Singels Crop Modelling S.A. Sugar Association Experiment Station Mount Edgecombe South Africa Tel: 27 31 593205 E-mail: singelsa@sugar.org.za
Date: Sun, 05 Oct 1997 03:47:52 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 2 Oct 1997 to 4 Oct 1997
Date: Sun, 5 Oct 1997 03:47:52 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 2 Oct 1997 to 4 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There is one message totalling 36 lines in this issue. Topics of the day: 1. More on history
Date: Fri, 3 Oct 1997 09:15:56 -0500 From: "E. John Sadler" (sadler@SUNBRN.FLORENCE.ARS.USDA.GOV) Subject: Re: More on history Greetings, Raul Vera has contributed some important citations, apparently mostly from the range science direction. These would have been generally under-represented in my work, and generally not available in most computer searches. The Duncan et al 1967 Hilgardia work is the one I mentioned, but the rest are new to me. Has anyone found a historical treatment of ecological modeling? Or forestry, entomology, or wildlife? Keep up the discussion. Cheers John ============================================================== E. John Sadler, Ph.D. USDA-ARS sadler@florence.ars.usda.gov Coastal Plains Soil, Water, and Plant Research Center 803-669-5203x112 (voice) 2611 West Lucas St. 803-669-6970 (fax) Florence, SC 29501-1241 U.S.A. ==============================================================
Date: Tue, 07 Oct 1997 03:49:54 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 4 Oct 1997 to 6 Oct 1997
Date: Tue, 7 Oct 1997 03:49:54 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 4 Oct 1997 to 6 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There are 2 messages totalling 47 lines in this issue. Topics of the day: 1. Equation for plant growth (2)
Date: Sun, 5 Oct 1997 13:52:53 +0000 From: drake@EROLS.COM Subject: Equation for plant growth Have the results of any research been used to formulate an equation for plant growth? For example, the basic "water + CO2 + light energy = growth" formula; has there ever been a calculated ratio of CO2/light energy (x amount CO2/y amount of lumens, for example)? If such a ratio and equation do exist, have any been formulated that take into account temperature and nutrients? For instance, in the above equation iron would play a role. Any help with finding this information would be greatly appreciated. Thank you.
Date: Mon, 6 Oct 1997 14:41:34 -0500 From: Ranjan Muttiah (muttiah@BRCSUN0.TAMU.EDU) Subject: Re: Equation for plant growth Park Nobel (Biophysical plant physiology and ecology) has the efficiency at slight below an average of 34%: 8 photons of intercepted light per mole of CO2. Mostly light in the red range is used (680 nm = 4.41 x 10^14 hz): by E = hv = 176 kJ/mol. For 8 photons, 8*176 = 1408 kJ/mol. Net Gibbs energy change H2o + co2 reaction is 479 kJ/mol for glucose. Therefore "efficiency" = 479/1408 ~= 0.34 If you change the environment (temperature mostly) the Gibbs free energy will change. There is a detailed theory on photosynthesis in the latest Physics Today article (using Excitons in QM). Ranjan
Date: Wed, 08 Oct 1997 00:03:25 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 6 Oct 1997 to 7 Oct 1997
Date: Wed, 8 Oct 1997 00:03:25 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 6 Oct 1997 to 7 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There is one message totalling 32 lines in this issue. Topics of the day: 1. Re[2]: Equation for plant growth
Date: Tue, 7 Oct 1997 08:40:31 +0100 From: Laurence Benjamin (laurence.benjamin@HRI.AC.UK) Subject: Re[2]: Equation for plant growth In response to the enquiry re equations for plant growth, you may be interested in knowing that my colleague and I published an equation for the growth of individual plants relating the growth of each plant to specific environmental factors;- light, temperature, etc. The equation was based upon ohm's law with each factor considered as one of a series of conductances for growth in series. The model gives good fits to the growth of isolated plants and those in communities. Aikman and Benjamin (1994) A model for plant and crop growth, allowing for competition for light by the use of potential and restricted projected zone crown areas. Annals of Botany 73 185-194. Laurence Benjamin Horticulture Research International Wellesbourne Warwick CV35 9EF United Kingdom tel direct line +44 1789 472024 tel switch board +44 1789 470382 fax +44 1789 470552 email laurence.benjamin@hri.ac.uk http://www.hri.ac.uk
Date: Thu, 09 Oct 1997 03:49:01 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 7 Oct 1997 to 8 Oct 1997
Date: Thu, 9 Oct 1997 03:49:01 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 7 Oct 1997 to 8 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There is one message totalling 68 lines in this issue. Topics of the day: 1. References
Date: Tue, 7 Oct 1997 13:22:21 +0100 From: Federico Preti (preti@UNITUS.IT) Subject: References Excuse me, how can I write to all the AG-MODELS list? Some time ago it was possible for me... Thanks, Federico Preti I would like to send them the following message: Dear colleagues, ) please, someone could give me the correct version of the following )References: ) ) ). Hoffman, Rhoads and others (???) in ASAE monograph "Management of Farm )Irrigation Systems" ) ). Kanwar, R.S., (???), "Agrochemicals and water management", ???, 367-387 ) ). ASA and/or SSSA handbook on "Irrigation of agricultural lands" ) ). ASA and/or SSSA handbook on "Soil Analysis Methods" ) )Thanks a lot! )Federico At 10.22 25/09/97 -0600, you wrote: )You are not authorized to send mail to the AGMODELS-L list from your )preti@TUS001.UNITUS.IT account. You might be authorized to send to the list )from another of your accounts, or perhaps when using another mail program which )generates slightly different addresses, but LISTSERV has no way to associate )this other account or address with yours. If you need assistance or if you have )any question regarding the policy of the AGMODELS-L list, please contact the )list owners: AGMODELS-L-request@CRCVMS.UNL.EDU. ) )------------------------ Rejected message (33 lines) -------------------------- )Received: from tus001.unitus.it by crcvms.unl.edu (PMDF V5.1-7 #17254) ) with SMTP id (01IO2176B564007OMO@crcvms.unl.edu) for agmodels-l@LISTSERVER; ) Thu, 25 Sep 1997 10:22:08 CST )Received: from [193.205.144.142] by tus001.unitus.it; ) (5.65v3.2/1.1.8.2/20Jun95-0126PM) id AA07909; Thu, 25 Sep 1997 17:21:05 +0200 )Date: Thu, 25 Sep 1997 17:06:42 +0200 )From: Federico Preti (preti@tus001.unitus.it) )Subject: help for references )X-Sender: preti@tus001.unitus.it )To: AGMODELS-L@crcvms.unl.edu )Message-id: (3.0.1.32.19970925170642.006ab280@tus001.unitus.it) )MIME-version: 1.0 )X-Mailer: Windows Eudora Pro Version 3.0.1 (32) )Content-type: text/plain; charset="us-ascii" ) )
Date: Fri, 10 Oct 1997 00:03:18 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 8 Oct 1997 to 9 Oct 1997
Date: Fri, 10 Oct 1997 00:03:18 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 8 Oct 1997 to 9 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There are 2 messages totalling 96 lines in this issue. Topics of the day: 1. question about [NO3] in the stream from a natural watershed (2)
Date: Thu, 9 Oct 1997 11:04:23 -0400 From: wk14@CORNELL.EDU Subject: question about [NO3] in the stream from a natural watershed Dear Friends, I am working on simulation of soil-nitrogen dynamics in a natural, small watershed (15ha, and only permanent vegatation) in the Northeast US. However, I only have experimental [NO3]-data in the stream during the summer season for comparison. I would like to know the nitrate behavior during the winter also. Would you please help me for the following questions about [NO3] in the stream? (1) Is [NO3] roughly constant throughout the year for a natural watershed (assuming that there is no input from agriculture or industry)? (2) Generally, is [NO3] in winter heigher than that in summer, or the other way around? Thank you very much. I appreciate any information. Wen-Ling Kuo Agricultural & Biological Engineering Cornell University Ithaca, NY14853 wk14@cornell.edu
Date: Thu, 9 Oct 1997 08:54:18 -0700 From: Tom Hodges (thodges@TRICITY.WSU.EDU) Subject: Re: question about [NO3] in the stream from a natural watershed Are you thinking of total N (grams/day) or concentration (grams/liter) in the stream? After heavy rain or during rapid thawing there will be a lot of water and N may be diluted. During a hard freezing period (assuming there is any stream flow), I think little N will be leached from the soil as it will be frozen several inches deep (unless there is thick snow cover?) and any stream flow will come from deep ground water. This would be the period with the least total N (gm/day) as it would only be coming from ground water thru year round springs. During the rest of the year total N would fluctuate based on 2 factors - (1) net NO3 released by soil microbial activity (this activity constantly releases and immobolizes NO3), and (2) volume of water movement thru the soil to the stream. Concentration of N in the stream will fluctuate wildly depending on the volume of water flow and will be hard to relate to total N. Tom Tom Hodges, Cropping Systems Modeler 3030 W 4th Ave, #27 email: thodges@tricity.wsu.edu Kennewick, WA 99336 USA voice: 509-786-9207 Fax:509-786-9370, 509-786-9277 == HomePage http://www.tricity.wsu.edu/htmls/hodges == On Thu, 9 Oct 1997 wk14@CORNELL.EDU wrote: ) Dear Friends, ) ) I am working on simulation of soil-nitrogen dynamics in a natural, small ) watershed (15ha, and only permanent vegatation) in the Northeast US. ) However, I only have experimental [NO3]-data in the stream during the ) summer season for comparison. I would like to know the nitrate behavior ) during the winter also. ) ) Would you please help me for the following questions about [NO3] in the ) stream? ) ) (1) Is [NO3] roughly constant throughout the year for a natural watershed ) (assuming that there is no input from agriculture or industry)? ) ) (2) Generally, is [NO3] in winter heigher than that in summer, or the ) other way around? ) ) Thank you very much. I appreciate any information. ) ) ) Wen-Ling Kuo ) Agricultural & Biological Engineering ) Cornell University ) Ithaca, NY14853 ) wk14@cornell.edu )
Date: Sat, 11 Oct 1997 00:01:23 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 9 Oct 1997 to 10 Oct 1997
Date: Sat, 11 Oct 1997 00:01:23 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 9 Oct 1997 to 10 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There is one message totalling 70 lines in this issue. Topics of the day: 1. ANNOUNCEMENT: PhD opportunity in NZ: Grasslands modelling
Date: Fri, 10 Oct 1997 22:23:59 +1300 From: Graeme D Buchan (BUCHAN@TUI.LINCOLN.AC.NZ) Subject: ANNOUNCEMENT: PhD opportunity in NZ: Grasslands modelling Greetings from New Zealand. I am distributing the `advert' below (for a PhD project in NZ) to the AGMODELS-L Discussion Group, since the project will involve development of models for grasslands, including extension of models we have recently developed here describing the energy balance/ soil temperature regime of grasslands. **************************************************************** Announcing...... a Prospective PhD project: ** `Grasslands in a CO2-enriched World' ** Lincoln University in collaboration with AgResearch NZ are seeking a graduate to commence in 1998 a well-supported project investigating the effects of climate change (especially elevated CO2) on any of the following aspects of grasslands: * surface energy exchanges * plant water use * plant development and forage supply The project will involve: i) modelling; and ii) field measurements at AgResearch's major new `FACE' installation (i.e. the `Free Air CO2 Enriched' site, near Palmerston North), and also at sites with naturally-occurring CO2 springs in Northland. We are seeking a versatile science, engineering or other graduate qualified in environmental or agricultural science, plant science/plant physiology, or any related discipline. Prospective funding (to be applied for) will include a 3-yr Doctoral Scholarship, which will (if awarded) include stipend (NZ$ 16,000 p.a.) and tuition fees, BUT with the fees AT NZ RESIDENT LEVEL ONLY. N.B. To qualify for NZ resident fees, applicants must be either residents of NZ or Australia. (Though some French or German graduates may also qualify). In other cases, the (high!) fees of NZ$ 28,500 p.a. levied on overseas students would regrettably not be covered by the scholarship. Please direct enquiries AS SOON AS POSSIBLE (before 25 Oct '97) to: Dr Graeme Buchan, Reader in Environmental Physics, Dept of Soil Science, PO Box 84, Lincoln University, Canterbury, New Zealand Fax: (64) 3 3253 607 Email: Buchan@lincoln.ac.nz ********************************************************** Dr Graeme D Buchan, Reader in Environmental Physics & Environmental Education, Dept. of Soil Science, PO Box 84, Lincoln University, Canterbury, New Zealand (Citizen of Scotland and NZ) email: Buchan@Lincoln.ac.nz Tel. (64) 3 3252 811 Fax (64) 3 3253 607 **********************************************************
Date: Tue, 14 Oct 1997 00:02:30 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 10 Oct 1997 to 13 Oct 1997
Date: Tue, 14 Oct 1997 00:02:30 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 10 Oct 1997 to 13 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There is one message totalling 102 lines in this issue. Topics of the day: 1. FW: Position vacant - Agrometeorological data modeller
Date: Mon, 13 Oct 1997 18:15:00 +0200 From: "Gommes, Rene (SDRN)" (Rene.Gommes@FAO.ORG) Subject: FW: Position vacant - Agrometeorological data modeller ---------- From: owner-climlist To: CLIMLIST Subject: Position vacant - Agrometeorological data modeller
Date: 13 October 1997 10:44 Return-Path: (owner-climlist@lists.psu.edu)
Date: Mon, 13 Oct 1997 10:44:00 -0400 From: John Arnfield (johna@GEOGRAPHY.OHIO-STATE.EDU) Subject: Position vacant - Agrometeorological data modeller Sender: CLIMLIST Climatology Distribution List (CLIMLIST@lists.psu.edu) To: CLIMLIST@lists.psu.edu Reply-to: John Arnfield (johna@GEOGRAPHY.OHIO-STATE.EDU) MIME-version: 1.0 X-Mailer: ELM [version 2.4 PL23] Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit ------------------------------------------------------------------------ ---- -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= CLIMLIST Mailing Number 97-10-21 Forwarded From: aus.ads.jobs,sci.geo.meteorology,sci.math Origin: Alan Beswick (alanbe@dpi.qld.gov.au) ))))) DO NOT USE REPLY FUNCTION ((((( ))))) REPEAT - DO NOT USE REPLY! ((((( =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= AGROMETEOROLOGICAL DATA ANALYST QUEENSLAND CENTRE FOR CLIMATE APPLICATIONS. Resource Sciences Centre, Indooroopilly, Brisbane AUSTRALIA. PO3 - $40,444-41,161 p.a. VRN: DNR 350/97. The position is temporary until 30/6/2000. Key Duties: Undertake scientific and statistical research on issues pertaining to the development of interpolated data surfaces from sparse agrometeorological data, the development of synthetic weather and climate generators, and the production of agrometeorological data and hydrological data from various climate forecasting models. Skills/Abilities: Degree in Science, Meteorology, Mathematics or equivalent. Demonstrated knowledge of meteorological science the use of agrometeorological and hydrological data in agricultural simulation modelling and decision support the interactions of climate on biophysical systems. Demonstrated experience with statistical analysis techniques including multivariate methods, splines, and kriging development of interpolated data surfaces from sparse data points development of statistical weather generators the quantitative analysis of meteorological and spatial data. Extensive knowledge of scientific computing techniques Position Description: (07) 3406 2904 International: +61-7-3406 2904 WWW http://www.dnr.qld.gov.au/longpdk/QCCA_positions Enquiries: Mr Alan Beswick (07) 3896 9741 International: +61-7-3896-9741 email alan.beswick@dnr.qld.gov.au Closing Date: 5.00PM, Monday 5th November
Date: Wed, 15 Oct 1997 00:03:00 -0600 From: Automatic digest processor (LISTSERV@crcvms.unl.edu) Subject: AGMODELS-L Digest - 13 Oct 1997 to 14 Oct 1997
Date: Wed, 15 Oct 1997 00:03:00 -0600 Reply-To: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) Sender: Agmodels-L Discussion List (AGMODELS-L@CRCVMS.UNL.EDU) From: Automatic digest processor (LISTSERV@CRCVMS.UNL.EDU) Subject: AGMODELS-L Digest - 13 Oct 1997 to 14 Oct 1997 To: Recipients of AGMODELS-L digests (AGMODELS-L@CRCVMS.UNL.EDU) There is one message totalling 39 lines in this issue. Topics of the day: 1. Experience with UN-SCAN-IT?
Date: Tue, 14 Oct 1997 12:26:55 -0400 From: "Daniel P. Knievel" (dpk@PSU.EDU) Subject: Experience with UN-SCAN-IT? Dear AgModels Subscribers: Have any of you had any experience with the digitizing software "UN-SCAN-IT"? About two years ago I obtained a demo disk of the software, but it was unconvincing. It worked with internal data sets and the demo user could not imput their own data. I couldn't tell whether the demo ran a "canned" routine or whether it actually utilized the software to digitize a real scanned image file. I want to use "UN-SCAN-IT" to prepare graph materials for classroom presentation Thanks to anyone in advance for supplying evaluation comments. -DPKnievel ********************************************** Internet: dpk@psu.edu Web: http://www.cas.psu.edu/docs/CASDEPT/AGRONOMY/People/Faculty/KnievelDP.html U.S. Mail: Daniel P. Knievel 116 Agricultural Sciences & Industries University Park, PA 16802-3504 USA Phone: Office: (1-814) 865-1547 FAX: (1-814) 863-7043 **********************************************

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