First steps
The goal of the Rcentury R package is to run the CENTURY soil dynamics simulation from R on a command window. Since we do not provide any external software with this R package, you first need to download and install the Fortran version of the CENTURY 4.7 software locally. This can be done directly from the web site https://www.soilcarbonsolutionscenter.com after filling out a form. Two zip-files are automatically downloaded, which must then be unzipped into a local folder of our choice. The uncompressed folders contain all the necessary files, plus several user manuals and examples. Any question related to CENTURY must be addressed directly to the creators of that software. See contact information on the https://www.soilcarbonsolutionscenter.com web page.
The CENTURY Fortran executable can be used as a stand-alone software to be run on a Windows command-prompt console. To do so, just follow the instructions in the accompanying documents. Additionally, a series of ASCII files must also be prepared in advance, which will then be read when CENTURY is executed. Those files include:
- A set of up to 11 option files with extension ‘.100’, containing a large set of parameters. The name of these files is fixed.
- A single site file, also with extension ‘.100’, containing site-specific parameters. The name of this file can be chosen at will.
- A weather file, with extension ‘.wth’, that includes monthly data for precipitation and minimum and maximum temperature for the site.
- A schedule file, with extension ‘.sch’, which details the timing and sequence of all events in the simulation.
All these ASCII files, together with the executable ‘.exe’ programs, must exist in the same folder.
CENTURY 4.7 example files can be used as starting templates to prepare our own parameter files. Those example files are located in three sub-folders that are created when unzipping the CENTURY downloaded files:
- Grassland with grazing simulation ran for a site in Xilingol, Mongolia (sub-folder “/Century+Examples/Century Examples/1.soil_texture_ppt”).
- Plant production for different grass types with different relative temperature growth curves (sub-folder “/Century+Examples/Century Examples/3.plant_production”).
- DUke and Harvard forests (sub-folder “/Century+Examples/Century Examples/4.forest”).
In those folders we can also find the two executables century_47.exe and list100_47.exe that we will use in the simulations.
What is Rcentury for?
Editing and then saving on disk each of those input ASCII files individually is an extremely tedious and challenging task, particularly when our goal is to apply the CENTURY model to a large number of different sites, and/or under a variety of different climatic and land management scenarios. This manual process is also highly susceptible to errors, given the vast number of parameters that must be carefully tuned-up and adjusted.
Therefore, it is a significant improvement in workflow to be able to perform all these file operations from within a comprehensive software environment like R. As mentioned above, the goal of package Rcentury is thus to run CENTURY 4.7 (version Fortran) from within R. That includes preparing all files (treatments, schedule, weather and site characteristic), and then read and load the result files into our R session as a data.frame. Notice that Rcentury is NOT an implementation of the CENTURY equations in R code. Rather, it is an interface between the original CENTURY Fortran code and R, which guarantees that calculations are done via the actual CENTURY code.
How to set up the Rcentury session
To run CENTURY from a R session with the Rcentury package we may proceed as follows. First, package Rcentury must be install on our local computer. The package is publicly available at github and can be easily fetched:
devtools::install_github("https://github.com/emf-creaf/Rcentury.git")
#> Using GitHub PAT from the git credential store.
#> Downloading GitHub repo emf-creaf/Rcentury@HEAD
#> ── R CMD build ─────────────────────────────────────────────────────────────────
#> checking for file 'C:\Users\Roberto\AppData\Local\Temp\Rtmpuy8arK\remotes44a43da03685\emf-creaf-Rcentury-425a058/DESCRIPTION' ... ✔ checking for file 'C:\Users\Roberto\AppData\Local\Temp\Rtmpuy8arK\remotes44a43da03685\emf-creaf-Rcentury-425a058/DESCRIPTION'
#> ─ preparing 'Rcentury': (5.7s)
#> checking DESCRIPTION meta-information ... ✔ checking DESCRIPTION meta-information
#> ─ checking for LF line-endings in source and make files and shell scripts
#> ─ checking for empty or unneeded directories
#> ─ building 'Rcentury_0.0.0.9000.tar.gz'
#>
#>
#> Installing package into 'C:/Users/Roberto/AppData/Local/R/win-library/4.4'
#> (as 'lib' is unspecified)Then, we load it into our R session:
This ensures that all package functions are available at the R session.
Access to those folders is granted by using the R function “system.file”:
# Get paths.
path_in <- c(system.file("extdata/1.soil_texture_ppt", package = "Rcentury"),
system.file("extdata/3.plant_production", package = "Rcentury"),
system.file("extdata/4.forest", package = "Rcentury"))
# Check folder content.
# sapply(path_in, dir)Example files
There are two main ways to prepare the ASCII files that are required to run a simulation successfully, namely doing it from scratch or using the example files available with the compressed ‘.zip’. Hereby we will be concerned with the latter case.
As mentioned above, the Rcentury package includes the example files that accompany the ‘.zip’ file that we may download from the
Prepare a CENTURY simulation
The steps to follow to prepare a CENTURY simulation with the Rcentury package are as follows:
Download the CENTURY 4.7 files as two compressed zip files (as of October 2025) from the web site.
Unfold the zip files into a local folder. You will end up with a series of subfolders which enclose manuals and example files.
Next, create a directory where you will hold all required CENTURY files and the results of your own simulations. Those files include the 4 types of files described above.
Open RStudio
There are three example simulations that accompany the CENTURY ‘.zip’ files.
The ASCII files that are required by the CENTURY software can be read and write with functions that are provided with the Rcentury package:
- read_100/write_100: to read/write all CENTURY files with extension ’*.100’ save for site files.
- read_site/write_site: to read/write ers to create input site files (extension ‘.100’) for the CENTURY soil model.
- read_weather/write_weather:
- read_schedule/write_schedule: read/write *.sch CENTURY files.
- read_lis:
These functions allow us to first read the example files provided with the CENTURY software, change the parameters at will and then write the modified dataset on disk.
Once those files are available in the same directory where they two ‘.exe’ files are located, we can run CENTURY with the ‘century_run.R’ function. Internally, ‘century_run.R’ runs sequentially ‘century_47.exe’ and ‘list100_47.exe’, creating first a ‘.bin’ file and then an ASCII ‘.lis’, which finally be read with the ‘read_lis.R’ function. The output of the latter is, finally, a data.frame that can be manipulated and analysed within R.