custom activity

I suggest you add at least one customisable menu item in the "add activity" list:

There are many activities that happen in fields other then the ones listed that a landowner might want to keep records of. Examples are Rock picking, Fence repair, Tillage, Dug out maintenance, Custom grazing duration, grazing of own livestock, etc... If this is going to be the program to track my field activity, it should be able to track that. I suggest you create a list item "Other" which then could be labeled by the use as desired for different activities.