I see that you have mapped a lot near Gungu, Kwilu Province, DR Congo. Looks like you have already invested quite a bit of time in this project of remote mapping. I am not an expert in this region, but it seems to be great, meritious work!
I took a brief look and think that the Bing aerial picture data quality/solution in that area might be good enough to map smaller parcels of land used for farming (“substantial crops” as you said) within a kind of mixed “scrub”/“wood” land separately. It would be good and necessary to send us a link to the relevant object(s). Based on the screenshot you sent it is not possible to answer your question in a good qualified way. What is the zoom level (scale) of the screenshot?
I’m doing a lot of research and also some analysis about the Congo in the context of my study. When I read about several projects to renew roads and airports in the country I decided to start mapping since the rgc data OSM uses (roads, ferries and airports) appears to be from the 1970s or 80s and is extremely inaccurate (better than nothing though).
Well, I meant “crops of subsistence farming” - sorry about my English.
The position of my screenshot is -5.435101, 19.016720. The zoom level was low, probably 17 or 16.
Interestingly I just came across another problem: These crops aren’t perennial, that means they may be abandoned for several years for the ground to recover (Can be seen when comparing the BING and Google imagery). That makes it unbelievably hard to decide what to map and what not. Also your suggestion to actually map the crops should lead to some enduring work since there are so many of them.
Hope you’ll find all the material you need for an answer
To map that quickly, I suggest you to use JOSM to edit OSM. In JOSM you instal the fast_draw pluguin that allow you to draw lines only moving the mouse. I tag “wood” only to dense areas of woods. In the image you posted seems to have farmlands, woods, meadow and isolated trees (natural=tree).
Look at this video: https://www.youtube.com/watch?v=xqDd-Crk3o4