set defaults for new ED2IN vars

[Aariq]

Description

Sets some arbitrary defaults for new variables in ED2IN file. These are required for the ED2IN file to be parsed, but I don't think they actually are used. The ED2IN template says "These variables are used to define the additional soil properties needed for SOIL_HYDRO_SCHEME=2." and in this ED2IN file I've set SOIL_HYDRO_SCHEME=0.

Defaults came from googling the description of the variable with the word "typical" and "soil".

Also fixes a mistake in #3035 that added new variables not in the ED2IN template after the $END tag.

Motivation and Context

Required variables for development version of ED2 to run.

Review Time Estimate

• Immediately
• Within one week
• When possible

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Extremely unlikely to break anything, and I can't test if it works until the PR gets merged and the docker container gets built by GitHub actions.

Checklist:

• My change requires a change to the documentation.
• My name is in the list of CITATION.cff
• I have updated the CHANGELOG.md.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[Aariq]

Installed on Welsh server and tested with development version of ED2. Both supplying the new template and supplying new tags with pecan.xml work.

[mdietze]

Not sure I understand why you switch out variables for hard-coded constants. Doesn't this eliminate the ability for PEcAn to set these variables?

[Aariq]

These are new variables that didn't exist in previous versions of ED2IN. I assumed I would need knowledge of soil chemistry to connect these up to PEcAn in some way, but if that's not the case I can take a look at how other ED2IN variables are done and take a crack at this. Also, I'm pretty sure they aren't used unless another hard-coded variable is changed.

[mdietze]

So if the mysl* variables don't exist anywhere else in the code I'm OK with this PR, though I do think the soil.nc files do have most of these variables, if one wanted to set up the ability to specify these via code.

[Aariq]

I'll open an issue as a reminder to add this in the future