Group of C++ classes that are used to write or read the field operations to be used in NitroEurope Component 5. The file cropOpReader.cpp provides entry to a simple program that reads the file that provides the detailed ecosystem models with field operation data. The program creates instances of classes specific to individual field operations (e.g. tillage, harvesting). These classes contain functions that access operation-specific data (e.g. amount of nitrate applied in a fertiliser application). The program outputs the year, Julian day, operation name and operation code to console.