Your First Run

This page assumes you have never used the wrapper before. Follow it top to bottom.

0. What you need first

DSSAT installed on your computer. On Windows this is usually a folder like C:\DSSAT48 that contains DSCSM048.EXE and crop folders (Wheat, Maize, …).
R (4.1 or newer).

The R packages the wrapper uses. Install them once:

install.packages(c("DSSAT", "dplyr", "tidyr", "lubridate", "DBI", "RSQLite"))

1. Load the wrapper

You only ever source one file — it loads the rest for you:

source("R/DSSAT_omniwrapper.R")

(Use the full path if you are not in the repository folder, e.g. source("C:/Users/you/DSSAT-wrapper/R/DSSAT_omniwrapper.R").)

2. Run a shipped example (copy–paste)

Every DSSAT install ships example experiments. Here we run the wheat one. You do not need to know the model name — the wrapper figures it out from your DSSAT install (this is "auto-detection").

result <- DSSAT_omniwrapper(
  model_options = list(
    DSSAT_path   = "C:/DSSAT48",                       # <- your DSSAT folder
    DSSAT_exe    = "DSCSM048.EXE",                      # the DSSAT program
    project_file = "C:/DSSAT48/Wheat/KSAS8101.WHX",    # an experiment file (.??X)
    suppress_output = TRUE                             # hide DSSAT console spam
  ),
  situation = "KSAS8101_1",   # which treatment: <experiment name>_<number>
  var       = "GSTD"          # the variable you want back (here: growth stage)
)

3. Look at what you got back

result is a list with two parts:

result$error                       # FALSE means the run succeeded
sim <- result$sim_list[["KSAS8101_1"]]   # the data for your situation
head(sim)                          # a data frame: Date + the variable you asked for
nrow(sim)                          # how many daily rows came back

A good first run means: result$error is FALSE, nrow(sim) is greater than 0, and your variable (GSTD here) is one of the columns.

4. Run it for YOUR OWN data

Change three things in model_options:

DSSAT_path → the folder where DSSAT is installed on your machine.
project_file → your experiment file (a .??X file, e.g. .SBX soybean, .MZX maize, .WHX wheat). It can be inside the DSSAT crop folder or your own.
situation → "<experiment file name without extension>_<treatment number>", e.g. the first treatment of MYEXP01.SBX is "MYEXP01_1".

If you want a different output variable, change var (e.g. "CWAD" for above-ground biomass, "HWAM" for yield). You can also use a friendly name like "biomass" or "yield" — the wrapper maps it to the right column for that crop.

5. If something goes wrong

Run the self-check first — it tells you exactly which file or setting is missing before you blame the model. See Self-Check and Validation.

DSSAT-wrapper Guide