thanks for thr forum whats do you thinks abouts this paper

https://www.mcs.anl.gov/~emconsta/Repository/Papers/Zeng_2013.pdf

Thanks for sharing this paper. I will get back to this soon.

Thank you so much for this forum and this forum is much helpful for young researcher and crop modeler also

Hi, I hope you are doing well, I have a question regarding GCMs and down scaling Can we use marksim (the link below) to obtain the RCPs data.

http://gismap.ciat.cgiar.org/MarkSimGCM/

Hi,

I think MarkSim has been recognized by many international institutes. Crop modellers have been using this to simulate/generate weather data for a long time.

Cheers!

Hi Jaime Cuauhtemoc Negr,ete,

I am reading the paper now you shared. On what aspect you want to have comments?

Cheers!

Happy to join in this forum and also discuss about the crop modeling issues, which have been put forth. Looking forward for effective discussion.I have been following the crop models for more than 15 years. Even though several research, review papers are there in these lines, just I wish to know whether such models are being used in real implementation in the field any where by stake holders ( viz., Government Departments, Farmers, Policy makers etc) ? If so kindly post those details .

Hi currently i am working on temperature. If we increase temperature by 1.5 degree C, how can we feed this increment in temperature in model either we should add 1.5 to the daily met data or we will incorporate this 1.5 in environmental modification option in DSSAT?

Muhammad Bilal , Hello dear, I am also working on these aspect of DSSAT SUBSTOR Potato model, we can not directly increased the temperature by 1.5 degree C by adding the value in daily met data. We should go for environmental data option and then we select the range of temperature then it would be rise according to the monthly and seasonal mean of temperature.

Yogesh Kumar See the screen shot and please specify me that where we should add the temperature to be increased by 1.5 or 2 oC....

Muhammad Bilal If you put direct 1.5 degree C in maximum temperature it does not considers this and you are trying to changed the generalized way of weather modification and i will send the images of how to add the values regarding environmental modification in DSSAT

Yogesh Kumar Ok dear thank you very much for guidance

Do anyone of you have the setup of WOFOST model for the sensitivity analysis of Basmati Rice

Because the links given on the official websites does not have proper programme/software like we install DSSAT on the PC.

Or WOFOST does not run on windows?

https://www.wur.nl/en/Research-Results/Research-Institutes/Environmental-Research/Facilities-Products/Software-and-models/WOFOST/Downloads-WOFOST.htm

@Abilash Singh Chauhan, I have the set up of WOFOST Model but I am not sure about there is an inclusion of sensitivity analysis.

Okay

Dr Saab Yogesh Kumar

I will contact you soon.

Yogesh Kumar I am waiting dear.....

@Muhammad Bill, sorry for delay, I have sent the pictures of environmental modification in DSSAT very soon.

@yogesh Kumar Thanks dear

@Muhammad Bilal, First of all sorry for delay response but at that time we look forward and trying to find out your query.

Firstly select the simulation start date carefully and then proceed the simulation process by selecting Runs, Replication, Random number seed and crop module .....then proceed all the steps for simulation but we are mainly focussed in environmental modification ...... first you can add the three levels (either they are varieties and planting dates) then you select the simulation date in which you can select it growing season (from sowing to Harvest) then back to the environmental module and add the application including maximum and minimum Temperature or precipitation and co2 or Other parameters from its Normal during entire season (the effect of change in weather parameters from normal during whole season in any crop) that is key facts for environmental modification. If you didn't consider it in whole season and you put direct value in environmental modification Application then it doesn't consider it. Hope you understand but if there is any help from my side then most welcome. I have attached some photos which might be helpful for understanding the procedure of environmental modification

Hi Abhilash Singh Chauhan and Yogesh Kumar

Regarding sensitivity analysis in WOFOST, if it doesn't have an inbuilt tool, you may check with the developers if you can use any other software or if you can bypass (outsource) the process using some available programs online (such as R).

Cheers!

Uttam

Hello!

Has anyone used a model developed in tropics for temperate conditions, particularly for the regions of higher latitudes where the day length can go as much as 22 hours and maximum temperature has more weightage in the 24 hour cycle. Such conditions may affect the phenology computations for tropical regions or close to tropical regions by the models with routines majorly relying on thermal time.

Thank you.

Uttam

Uttam Kumar : If you are looking for models that are developed for regions where heating degree days pose a constraint, then Canadian models are good choices. In our case, the crop growth models rely on Growing degree days instead of the hour cycle. Not sure your question is geared towards this.

Dr. Arumugam Thiagarajan : Thanks for your comment.

Sorry If I was not clear before.

I will try that now.

I wished to have discussion, thoughts and comments on the following:

Major point: what happens when a tropical model is applied for higher latitudes?

In my earlier comment, I meant what is the performance of a crop model, developed by using tropical data, for higher latitudes, particularly for phenology predictions, considering all the factors involved; temperature, daylength and vernalisation.

In most crop models, the concept of degree days are incorporated as removing base temperature from the mean. In tropics where the day lengths can be around, example, 16 hours or less. In those regions that computation of degree days works fine, as the mean ((Tmax+Tmin)/2) is still representative of the whole day. But in higher latitudes days can be as long as 22 hours and the weightage of Tmax is much higher. Does the above concept of degree day computation still works in higher latitudes. What about the long long day lengths (22hr), does the tropical crop models handle this much long days (photoperiod effect and radiation effect)? The plant get exposed to less duration of Tmin in those regions; and how do the the tropical models handle the cases of vernalisation requirements? In these regions maintenance respiration is less (very short nights), what happens with the partitioning rules.

I am diving into those questions. and maybe more in the future.

Cheers!

@ Uttam Kumar ..... Thank you so much for bypass in WOFOST MODEL

Hello

Has anyone calibrated coefficients of vernalisation and photoperiod for phenology? What are your approaches in the situations when intuitive adjustment is the only option available?

Thanks

Uttam

Developmental stages are simulated when the accumulation of thermal development units (TDU) reaches pre-determined levels as specified by coefficients defined either for groups of similar cultivars (‘ecotypes’) or for individual cultivars. Daily TDUs are calculated as:

DTDUs = DTT x [(Minimum (VF, DF)]

where DTT (degree days, °Cd) is the daily thermal time, VF (0–1) is a vernalization factor and DF (0–1) is a day length/photoperiod factor. Terminal spikelet is reached when TDU reaches 400 °Cd. The duration from terminal spikelet formation to anthesis is assumed to be affected only by temperature, with the TDU requirement being provided as an input parameter in a file of ecotype characteristics. The default TDU requirement we used was to assume the equivalent of 5 phyllochrons (3 to end of leaf growth and 2 to more to anthesis), equivalent to 425 °Cd when the phyllochron is 85 °Cd per leaf.

Hi, I hope all of you will be fine. Anyone having idea of Using Integrated farm System Model (IFSM) or Holos model ar GLEAM???

Kindly share me

Muhammad Bilal Here is the email link for the HOLOS model; [email protected]

There is good support for the model. Dr. Roland Kroebel actively develops this project. Good luck

@ Muhammad Bilal

Thanks for your comment.

You say it what I did not specifically explained in my question.

Achieving the pre-determined degree days is easy. But I intended to get more information on the experiences of VF and DF calibration. Have you ever played with coefficients (0-1) of these two while doing a calibration?

" DTDUs = DTT x [(Minimum (VF, DF)] " this equation is very similar to liebig's law of the minimum. It means there is no sophisticated interaction among DTT x VF x DF. The degree days (DTT) of the day is adjusted with what is minimum for a certain day and becomes degree days of the day (DTDUs). This equation is same in most crop models. It's an established phenology simulation tool based on thermal time.

Uttam Kumar Dear I told what i understand...

and if it not helpful i apologize

Dr. Arumugam Thiagarajan Thank you very much for your comment

Muhammad Bilal

Discussions are always useful. So no worries.

Have a nice day.

Thank you:D

Hi

Does anyone has this book? Predicting crop phenology-Tom Hodges.

If you do, please share it in my personal inbox . Not sure if there is any copyright issue.

Thanks

Hello everyone

Does anyone knows about the similarity in DSSAT, INFOCROP and WOFOST model. What is the common factor in all three models Except its Weather file and Management file for common crops. Please explain with certain illustration and citation, if possible.

Hello again,

Does any one have questions and comments on the phenology simulation mechanisms in the crop models?

Hi Yogesh Kumar

About the similarities in DSSAT, INFOCROP, and WOFOST. If you have not recieved any helpful reply yet, probably I can try to suggest some whcih could help.

If you could explain what's your objective or what kind of similarities you are looking for (example; structural or functional) then I could zoom-in accordingly.

Uttam

@Uttam Kumar thank you for attention in my question I am looking about to know the functional similarities in above models. Could you explain in brief because I have given a interview then experts ask me to the similarities of above three models

@ Yogesh Kumar

Some general suggestions that you can look for:

1) Check the biomass generation mechanisms (radiation, transpiraiton, CO2)

2) Check the phenology algorithms and their components

3) Partitioning (is it supply and demand base or just a ratio)

4) Nutrient availability (interaction of soil organic matter, moisture and temperature)

5) Methods to decompose root, crop stubbles or other organic matter

6) Nitrogen partitioning to different organs

7) Cohort formation mechanisms

8) Mechanisms to simulate evapotranspiration

You will find a lots of similarities on those points, at least for INFOCROP and WOFOST as both have same pedigree. DSSAT could be a bit different.

When you have compiled those points then we can disscuss again, if you want.

Cheers

Uttam

@Uttam Kumar thank you for insightful information regarding comparison. I am work on it when I get some conclusion then I will share it in this forum. Regarding your view of similarities in WOFOST and INFOCROP model are right but components of model building and it's verification are entirely different from the DSSAT model. But again thanks for your kind response....... cheers

Hi all,

I have a question:

How much model evaluation (or validation) is critical and important? And In what cases it should be avoided or included?

Your thoughts and references on this particular matter are welcome.

Thanks

Hi all,

I have a question regarding the soil data input in the experimental file in DSSAT.

In DSSAT we need to add soil_ID along with soil texture, depth, however, these parameters are included in the soil file. Can we replace the information as -99 and DSSAT reads this information directly from soil file?

Hi, It's been a long time since I worked on DSSAT. I can't cleary say, but I would guess that you need to tell the interface which soil file or which location's soil it should take in. And if it is true, soil_ID could be the identifier and the bridge between the interface and the soil file. So you would, atleast, need that, I guess.

Uttam

Just to say Hello and keep it rolling.

I would like to put forth two questions for discussion:

1. What are the different ways to address current (or extreme) climate variabilities in crop production with the crop models? Considering that the produciton depends on various factors, what's best one to address that?

2. On the plant mechanism side; which traits could be included in the above quesiton? This will again depend on the crop and interested climate factors and their interactions.

If you have quesitons and would like to have others thoughts on those, please raise them here.

Cheers

Uttam

To find the diractions to the answer of above queasiton I suggeste these papers:

1) Temperatureextremes:Effectonplantgrowthanddevelopment.

Jerry L.Hatfield n, JohnH.Prueger: WeatherandClimateExtremes10(2015)4–10

2) Simulating the impact of extreme heat and frost events on wheat crop

production: A review

K.M. Barlow,∗, B.P. Christy, G.J. O’Leary, P.A. Riffkin , J.G. Nuttall: Field Crops Research 171 (2015) 109–119

3) Translating large-scale climate variability into crop production forecast in Europe. Gabriela Guimarães Nobre , Johannes E . Hunink, Bettina Baruth, Jeroen C. J. H. Aerts & Philip J. Ward . Scientific Reports | (2019) 9:1277 | https://doi.org/10.1038/s41598-018-38091-4

Thanks

Uttam