With maya.env File
The Maya.env file enable to specifiy some environment variables to be set when Maya is launched.
You can learn more where to find it and how to modify it in Maya documentation: Setting environment variables using Maya.env
For example if you did not install the package locally on each render nodes, you need to specify the Maya Module Path in this file.
As stated in the Autodesk documentation: "The variables set in the operating system take priority over any settings in the Maya.env file".
Which means that if one variable is already defined in the system, even if you define it in the Maya.env by replacing or appending something to its value, it will not be taken into account (except for some particular variables like MAYA_MODULE_PATH)... You should then be very cautious when using the Maya.env method and check that your environment variables values are really taken into account.