I have downloaded Open Street Map data from Geofabrik, where they provide relatively large chunks. Although I did recently have an issue where the downloaded data didn’t contain all of the streets that I could see in an OSM basemap in ArcGIS, and I’m not sure why there was such a difference, but it’s worth comparing if you use this data source.
We often extract agricultural areas from a land use/land cover map, so you could look for a provincial or national map that appears to represent your area well. If these aren’t available, you can try global land cover maps like MODIS MCD12Q1 or from the European Space Agency, and again really check their accuracy since they are both, as with all global data, imperfect.