Hi All,

I am new to DSSAT and crop modelling in general. I plan to use DSSAT v4 software to model maize production in North-Western Nigeria using weather data from 1975 - 2005.

However, the data I have are all monthly averages (from Jan-Dec for each year) of Tmax, Tmin, SRad, and Rainfall for all the weather stations that I have got. Please how can I generate weather data to fill in the missing dates (gaps) - (e.g., Jan 1st to 31st, Feb. 1st to 28, etc.).

Kind regards,

Nasir Anka Garba

________________________________________
From: DSSAT - Crop Models and Applications [[log in to unmask]] on behalf of Boote,Kenneth J [[log in to unmask]]
Sent: 19 January 2011 18:51
To: [log in to unmask]
Subject: Re: Using Xbuild to make many (i.e.) FileX files.

Steve,

Let me ask if you are trying to do with for specific management (different sowing date, N fertilization, cultivar) for each year.  OR, if you are trying to look at carry-over of water and N for cotton (in which case SEQUENCE is the only way to do it, as Kelsey Brandt advised in his email response).

BUT if you don't need differing management per year, then the best way to do this, is to use SEASONAL.  Just use a typical sowing date, typical N fertilization, and typical cultivar and sowing density.  In that case, create an SNX file that just sequentially takes the weather that you created for a given weather station.  You specify number of years to run.  So, all you would need to create is 4 SNX files.

If you want specific management (different sowing date, N fertilization, cultivar) for each year, then you will need to use File X, but you can have one File X per site, but 30 lines in the treatment section, each calling for 30 lines in the sowing date section, and maybe 30 lines in the Simulation Control Section (giving "start of simulation").

I hope you are planning to use the latest V4.5, as the V4.02 version for cotton is not all that well calibrated.  It was one of the most recently added crops and also one of the modeled crops that encountered the most change going from V4.0 to V4.5.

If you have not taken the DSSAT training course, it is offered at IFDC, Muscle Shoals, AL on May 9-18.  You would learn many of these skills there.

Good luck with this.
Ken Boote

-----Original Message-----
From: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] On Behalf Of Steven Mauget
Sent: Tuesday, January 18, 2011 2:51 PM
To: [log in to unmask]
Subject: Using Xbuild to make many (i.e.) FileX files.

Dear DSSAT Users:

I¹m planning to use DSSAT4 to model cotton production using 30 years of
weather data from  4 sites in west Texas ­ 120 cropping years total.  My
problem is that in reading the DSSAT4 Vol2 pdf and the Xbuild help file it
seems that creating the 120 COX Filex files necessary for all those model
runs  might be kind of labor-intensive. That is, in my reading of how Xbuild
works, I¹ll have to assign one weather file to each Filex file, and repeat
this for all of the 4 station¹s 30 cropping years. Or, I might create a
single template COX file and edit it to assign the different year¹s data for
each of the 4 weather station sites. But either way I use Xbuild 120 times
to create 120 COX files. I was wondering (hoping) if there was some way that
Xbuild could loop over the 30 years of  weather data for each of the
stations to create 30 COX files at once, but  the instructions and the
Xbuild GUI do not suggest that is possible.

Am I reading the instructions wrong? If not, does anyone have any
suggestions for creating 120 FileEX files that involves less work?

Thanks for the help and advice,

Steve Mauget