Black?
Yes! Murzynka.
Scythes knocking together?
Nope, I said it is a hollow sound while metal makes clanking noise. Not wheat or other grains coz I said it has lasted for 3 weeks, while a combine harvester deals with crops in 1 hectar in 30 minutes.
Hint - it is veg harvest.
knocking together the heads of incalcitrant farm labourers.
:):) Sorry, no, none of my neighbours employs workers, the family does the job. Except adult children who refuse to work in the fields. They prefer cleaner jobs.