Using WinEPIC V6

[Erik Feuer]

Hello,

I'm using WinEPIC for yield calculation in Germany.

now i got two questions 1st i have daily timelines for the weather and want to use them for the simulation time, whrer and how can i implement them in WinEPIC
and the second one i want to adjust the plant growth parameters and found no place where i can set the PHU for my plants.

Greetings Erik

[Luca]

Dear Erik,

To import weather data in the WinEPIC database (managed by Microsoft Access) you can use the Weather Import tool that is downloadable from the Blackland website (link: https://epicapex.tamu.edu/model-executables/weather-import/).
I have not tested it recently so, give it a try and do not hesitate to contact me if you have any problem.

For your second question, you can set the PHU in the management window. When you schedule a planting operation scroll the window on the right and look for the column called GDUs.

Let me know if you need more help.
Cheers,
Luca

[Erik Feuer]

Thx Luca,

I want to give it a try but now i got another problem, there is MJ/m² used but i only have W/m² my idea was to transform it like 1 MJ/m² = 11.57 W/m² would you say this is correct?

Cheers,
Erik

[Luca]

Hi Erik,

This is a kind of tricky conversion and time ago I spent some time on it (and from time to time I still have to revise the steps...).
Anyway, first of all here you can find information form the USDA-NRCS website about the solar radiation conversion. I started from there to do some calculation and I ended up with a conversion factor of 0.0864 to convert W/m2 to MJ/m2/day.

Time ago I found a nice explanation on internet but I can't find the web page now so I am going to type here the content but I can't cite the source.

"No power and energy conversion is possible, but

E=Int(t1,t2) P dt; Int representing the integral from t1 to t2

Average solar energy fluxes during sufficiently small periods (e.g. 20 minutes) are sufficient to estimate daily solar energy amount using sums during the periods.
E.g., suppose global solar energy flux averages centered at shown times are:

10:10 500 W/m^2
10:30 530 W/m^2
10:50 270 W/m^2

Time period is 20 min = 12 sec, then total solar energy amount during the hour is:

E = (500)(1200) + (530)(1200) + (270)(1200) = 1560000 J = 1.56MJ/m^2  "
End of the citation.

As consequence we can multiply the solar radiation reported for one day for the number of seconds in one day (86400) and then we can divide the result by 1,000,000 to convert J to MJ. Or, in one step, we can multiply the solar radiation (W/m^2) times 0.0864.

Please, verify if this make sense to you.
Luca

[Erik Feuer]

thx Luca,

this is the same factor i calculated
1 MJ/m² = 11.57 W/m² or
0.086 MJ/m² = 1W/m²

thx for the validation
Erik

[Erik Feuer]

ok now i got some other problems.

maybe you could help me i run some simulations but now the Grain yield is much to smal as i need them now is my question where could this result from.

now as loger i try to find the mistakes the less is running, maybe someone of you could check my *.mdb file if i made any mistakes. at least i want to use it very simple but i'm afraied it needs mor input as i thought

thx for help

if any helper needs some more detailed info about my settings just ask me.

[Luca]

Erik,

We cannot run your dataset because at least the DLY file is missing.
Moreover, have you checked your output file to understand why the yield is low. For instance in the .ACY file (or in the annual crop yield table if you are using the output database) you can look at the columns that report information on the crop stress. This might help you in understanding why the model is simulating a low yield.

Then, if the model is crashing, we must be able to replicate the error in order to help you.

Let me know if you find out something about the stress and if you have tried something to reduce the stress and increase the crop yield.

Luca

[Erik Feuer]

Luca

because i don't know which data you'll need, so i hope i took the rigt one

I thought about and I think it could be helpful if you check my Data/Setup settings, if i made them all correct.
because of this you schould know my thoughts.
i'm only interested in the yield of some crops, which are: Potatoes, Corn, Canola Polish, Corn Silage, Spring Wheat, Winter Wheat and Shugar Beets.
as Soil I added 4 new different types Named: S, Sl, Ul and Us under the Archer, TX template
I'm not interested in costs, Fertilizers or Pesticides only wont to make shur there is no Nutrient stress.

the idea is to adjust the growth parameters of the crops to fit to the real yield. and there was the problem for example Potatoes whre Epic simulated 0.2 t/ha grain yield and i need around 9 t/ha i tried to adjust the parameters but the yield did not change.
and the other stress parameters were very low or nearly did not exist.

I hope you can help me in some way.

an other problem was that winter wheat is listet twice in the Crop Data and i can't change the parameters of this crop.

and the cras occures every time i want to run m added runs and the massage is :Field 'Batch_Error.Comment' cannnot be a zero-length string.frmRun2 (cmdRunEpic_Click)

Erik

[Luca]

Erik,

Several files are still missing. The best thing you can do is to run the model from the WinEPIC interface and using the setup that is giving you the error, copy the entire EPIC folder located in the WinEPIC directory, remove the executable from the EPIC folder, compress the EPIC folder and upload it. If it is too big for the forum, please find a different way to send it.

Then, as general comments:
1) the crop growth parameters should be the last parameters to adjust unless you have specific reason to do modify them (observed data, or if you want to simulate different varieties of the same species...). This is because adjusting the crop parameters you can obtain the right answer for the wrong reason. This means that adjusting the crop parameter you can force the model to give you the numbers you want for the crop yield or crop biomass without considering the dynamics involved in the entire system.
For instance, the simulated yield is lower than the observed one because of nitrogen stress caused by a bad simulation of the nitrogen dynamic. If you change the radiation use efficiency, the model will simulate a higher crop yield but the simulation of the nitrogen dynamic will be still wrong. Again, this is an example of how you can get the right answer (good simulation of crop yield) for the wrong reason (unrealistic radiation use efficiency instead of adjusting the nitrogen dynamic).

2) For the potato yield, check if the crop biomass is reduced by the operation you have right before the harvest operation. Moreover, keep in mind that all the yield simulated by the model are reported as dry weight.

Luca

[Erik Feuer]

Luca,

ok i tryed this one hope you can now open and run the files

https://drive.google.com/open?id=0BxrXQGdEJcCBSms0Qk43a0hnTlU

Erik

[Luca]

Looking at your data, I think that in your simulation the problem is created by more than one factor.

I have seen that in your simulation, the potato is planted in late January but, because of the cold weather, it germinates only around May 10. Then, every year it is harvested on June 5, so the plant has a growing season of only one month. Unfortunately, there is not much you can do about this. You can reduce the number of heat units required for the germination (crop parameter GMHU), but doing so it is probable that the crop will suffer temperature stress because of the low temperature.

Somehow related to this point, I have see you are using 1075.41 PHUs and, because of the short growing season, it is impossible to accumulate such amount of heat units (or GDU). As consequence, the biomass accumulated by the crop is limited. You can consider to reduce the PHU to replicate the actual growing season of potato in Germany. Eventually, you can see the definition of PHU in the EPIC user manual.

Another point is about the plant population. You have set a plant population of 3 plants/m2 (that sounds reasonable to me), while in the crop table (file crop.dat) the values of PPLP1 and PPLP2 are 18.47 and 30.77 respectively (see the EPIC user manual for the description of these crop parameters). These values looks high to me and, for sure, they are way too high compared to the plant population you are using in your simulation. You can revise the value of these parameters according to the data related to the normal plant population used in your area and the leaf area index development curve.

Let me know how if you manage t improve the result of your simulation.
Luca

[Erik Feuer]

thx Luca,

may I ask you if you could check my general settings for cropping systems and management if i made every thing right there for Potatoes, Corn, Corn Silage, Canola Polish Spring Wheat, Winter Wheat and Sugar Beets, because i just took a tamplate and just switched the Crop, so I'm not shure if this is all correct. and could you eventually link me an explanation for the PPLP Parameters, cause I'm not quite shure how to use them.

because you mentioned the dry weight which percentage of water is this dry weight? and do you have an faktor for Potatoes and sugar beets to get the wet/field weight?

Erik

[Luca]

Erik,

You can find information about the PPLP parameters in the EPIC user's manual. You can download it from this link: http://agrilife.org/epicapex/files/2015/10/EPIC.0810-User-Manual-Sept-15.pdf

About the dry weight, the model consider dry weight as 0% of water. I don't have values for average water content of potatoes and sugar beets but I am quite sure it is above 60%. I am sure you can find plenty of scientific literature doing a simple search on internet.

Last thing, what do you mean with "check the general setting for cropping system and management"? Are you concern about any specific value? If you used a template with the same crops you need for your simulation, this could not be enough. In fact, some other inputs may require to be adjusted to reflect the condition of the field/area you want to simulate. An example of these inputs is: planting and harvesting dates, potential heat units required by the plant to reach maturity, and plant population.

Luca

[Erik Feuer]

Luca,

may it be possible that we could make an skype/teamviewer meeting to solve some of my problems, because i got always the same errors and have no idea to solve them.

Erik

[Luca]

Hello Erik,

What are the errors you are having? Can you take screen shoots with the windows showing the error message?

Luca

[Erik Feuer]

Hello Luca,

after i reinstalled it worket a bit but now the same Errors and new occure

Erik

PS: because I'm running out of time is there an easy way to convert my settings fro WINEPIC to the EPIC 0810 and try to work with this?

[Luca]

Erik,

You can easily move from WinEPIC to EPIC0810. In fact, WinEPIC is only an interface to run EPIC.
To run EPIC, open the WinEPIC installation folder, you will find a sub-folder named EPIC. Inside the EPIC folder you will find the EPIC0810.exe executable and several text files with different extensions such as .DAT, .DLY, etc. These files are created by the WinEPIC interface when you execute the model, therefor the data contained in these text files are referred to the last simulation you run with WinEPIC (the interface overwrites these files every time you run the model).
You can run EPIC directly from this folder or, better practice, you can copy and paste all the files in a different folder and work from there. You can edit the text files using any text editor and run EPIC with a simple double click on the executable (or run it using the command prompt).
While using the text files, be aware that the format and "width" of each variable is usually important! Are you familiar with the concept of free and fixed format?

Let me know if you need more information.
Luca

[Erik Feuer]

Luca,

sorry that i answer one month later, I extended my working time by two more months, do you have any suggestions for my posted errors? what i could do to fix them. or would it be better using the way you just explained?

and i'm not familiar with free and fixed format.

Erik

[Luca]

Erik,

It is impossible to tell what is causing the error looking at the Word files you have attached.
This is what we can try to do, run the simulation that is giving you the error. Go the WinEPIC installation folder and make a copy of the EPIC folder. From the EPIC folder you have copied, delete the EPIC executable. Compress the folder you have copied and share it with me using something like Dropbox or Google Drive.
In this way, I can try to replicate your error on my computer to understand what is causing this issue.

Luca

[Erik Feuer]

Luca,

as i copied the WinEPIC Folder my anti Vir found something:
it said, SMRCLAS.exe contains 'TR/Rogue.1338738' could this cause some problems?

and attached i send you my whole WinEPIC Folder, because i can't run any of the defined runs any more the list where to choose is completly empty.
https://drive.google.com/open?id=1DaruRIMlpKlrMd1a4vFjclMKhIexAzeF

Erik

[Luca]

Erik,

I am sure it is not the problem. That executable is created during the installation process and it is in my WinEPIC folder too.

I was not able to replicate the error shown in the attached Word document. I ran all the spring wheat - dryland - conventional tillage managements you have in the database and everything worked fine. What you can do is to tell me the number of the run that is giving you the error.
One more thing, looking at your results, it seems that you are planting and harvesting corn, even if the management is called spring wheat. Is it what you wanto to do? Moreover, most of the time the corn is harvested in December.

Luca

[Erik Feuer]

Luca,

this seems that there is an unkown problem with my computer, because you were not able to replicate my errors.

do you have an idea how we could solve this?

I want tu start any run out from WinEpic and always get the same result: "Field 'Batch_Error.Comment' cannot be a zero-length string.frmRun2 /cmdRunEpic_Click)"
and then it crashes

Erik

[Luca]

Copy your database somewhere in your computer, uninstall WinEPIC and install it again. Copy your database back in the WinEPIC folder and try to re-run the simulation that is giving you the error.

Luca

[Erik Feuer]

Luca

ok i'll write to you tomorrow it seems my notebook got some bad issues will fix this first

Erik

[Erik Feuer]

Luca,

I reinstalled Win EPIC but I get the attached Batch errors, and i have no idea why
If i use the other weatherstation i get no problem.

and i got an other question where and how do I set the used crops for my runs because this is not explaind in the manual. like you said before it is not my intension to simulate spring wheat with corn.


Erik

[Luca]

Erik,

I can't help you with the error looking at the database. I will need yourinput files to understand what is causing the problem. Since you say that the model works fine using a different weather station it seems that the weather data is the culprit.
Is the required DLY file in the EPIC folder? Is it formatted properly?

For your second question I am not sure what you mean. You set the crop when you build or edit the management file.

Luca

[Erik Feuer]

Luca,

I solved some of this issues but now i have the problen, the Plant is using twice the aviable water which should be there, because of this there is no differenc in the yield of the two areas. and an other question is which factor can i use to increase the yield i expect around 48 t/ha but the simulation is only 3,7 t/ha.

the only big difference from the last one are only the *.mdb Files so you can use the rest from the Drive link https://drive.google.com/open?id=0BxrXQGdEJcCBSms0Qk43a0hnTlU.

Hope you have som suggestions for me

Erik

[Luca]

Erik,

For the simulation of the yield, keep in mind that the yield reported in all the output files is reported as dry weight. Maybe you are comparing dry weight with the weight of biomass that included moisture.

To check your files, could you please refresh my mind? What are you trying to simulate? What are you testing or what are your treatments? As you can see I am dealing with several users here and I can't remember the simulation of alllof you :)

Thanks,
Luca

[Erik Feuer]

Luca,

atm I just want to compare two different weather stations one with more the other with less rainfall, but I don't find an real difference, because for the drier one there should be water streff for the plants but the simulations don't show them.
and the available water is much too high as i thought.

Erik

[Luca]

Are the two weather stations different?
Are you applying irrigation?
Which crop are you simulating and what is its growing season?

We need more information in order to be able to help you.

Luca

[Erik Feuer]

Ok Luca,

here are more detailed Informations:
the two weatherstations have a rainfall like 383mm to 173mm from May till October,
i don't apply irrigation, but after looking on the results there is no need for irrigation.
and i'm simulating Corn

but i think the error occous from "Mo Root zone soil water" because there is not really less than 80mm.
and i got an Sand which should normaly run out of water fast.

maybe you got some ideas where i could fix the problem.

Erik

[Luca]

Could you send the .OUT file of your simulation?

Luca

[Erik Feuer]

because it is over 300 MB here is the link for the OUT and
input database
https://drive.google.com/open?id=0BxrXQGdEJcCBSms0Qk43a0hnTlU

for an better understanding how is "Root zone soil water" defined in EIPC is this the water content (in mm) in the root zone for corn 2,5m deep, or is this completly aviable water for the plants.

could you check the Soil_tables too, because there should be an equal homogenious soil for the whole area, just simple sand. I think there occures some mistakes too.

Erik

[Luca]

Erik,

Could you please send me just the .OUT file, not the entire database of your simulation. Just run the model for the simulation you want me to check, then send me the .OUT file that you will find in the EPIC folder that is inside the WinEPIC installation folder.

For the root zone soil water, it is the amount of water (in mm) that is available to the crop (above wilting point) considering the minimum depth between maximum root depth of the crop and soil depth.

I am not sure about what you mean / what you are asking about the soil table. If this is the soil you want to use in your simulation, I should be able to check it directly in the .OUT file.

Luca

[Erik Feuer]

Luca,

ok now i understand which file you ment, in this OUT file is FC SW (m/m) the Soil water content at Field Capacity if yes there schould only be 11% and WP SW (m/m) for the wilting Point, there should only be 3% how can i make EPIC to use MY input data and not calculating something miracle out of them. because if SW is the "Root zone soil water" there is my problem coming from.

hopefully this is now helping you to help me solving my problem.

for the soil table is there an automated operation for the upper soil layers by calculating the plow?

another question where could it come from that the date of harvest differs from the date in the management?

Erik

[Luca]

Erik,

Yes, this is the file I need. I think this simulation is the one based on the weather station with the larger amount of precipitation (it seems that the average total precipitation for the period May-October is about 395 mm).
Now, could you please run the model using the weather station with the low precipitation and send me the resulting .OUT file? In this way I can make a comparison between the two simulations.

One thing I can see is that the soil you are working with is very deep (5.41 meters, but it seems that you are using the same input data for all the layers you have.

I will keep an eye on this when you will send the second OUT file.

Luca

[Erik Feuer]

Luca,

here is the second one with the other weather station.

the soil parameters are all the same for the whole area, because i should simulate for an homogeneously sand with an far away Groundwater that's why, do you think the soil is set to deep?

my Problem with the soil is, i have an watercontent at wilting point with 0.03 m/m and Field Capacity of 0.11 m/m these two are insert as input parameters but in the OUT File they are much too high. because it is an sand and should dry out very fast.

Erik

[Luca]

Erik,

Are you providing information on the wilting point (WP) and filed capacity (FC)? If yes, you have to change the method by the model to estimate those values.
In fact, in your previous message you said that WP and FC are 0.03 and 0.11 respectively, while from the output you sent I can see that the model is using the dynamic Rawls method to estimate those data with values between 0.392 and 0.411 for FC and 0.194 and 0.204 for WP.

If you are providing those data you want to use the option "inputted wilting point and field capacity". You can do so changing the value of ISW (Field Capacity/Wilting Point Estimation) in the control table.

Let me know if this helps.
Luca

[Erik Feuer]

Luca,

thank you this help me so much, now i want to add auto irrigation so i get for one simulation no water stress and then comparing it with no irrigation, what would you recomend that i should use especially for BIR under the view of scientific citation like what stands Plant Water Stress factor stands for. i checked some literature and found 1500 kPa as starting point for water stress, i implemented this value but i see no change. now i decided that the irrigation should start every time when the program starts to count water stress, so my plants don't get any water stress. because i want to compare the two runs one with no irrigation and water stress and the other with irrigation to prevent any water stress.

and because it is working now i want to add additional crops, now i need to know where to find the column for the yield for potatoes and shugarbeets

Erik

[Luca]

Erik,

 

You can think of the plant water stress factor as the severity of water stress allowed by the automatic irrigation scheme. The more severe is the stress allowed, the less water will be applied and vice versa.

In EPIC the water stress is calculated considering the actual plant water use (affected by the available water) and the potential water use. A BIR value of 1 will apply water to eliminate water stress (if other parameters related to automatic irrigation allow to apply enough water).

You can get some extra information from the APEX theoretical documentation (https://agrilifecdn.tamu.edu/epicapex/files/2017/03/THE-APEX0806-theoretical-documentation-Oct-2015.pdf)

Yield for potato and sugar beet should be reported as forage yield in the ACY file.

Let me know if you have problems with this.

Luca