My copy of the Compact OED (which is the full text but reproduced micrographically - these days I need a magnifying glass to read it) gives two meanings for the verb 'to sheave'. The first, which I would have said was *relatively common usage to a UK national of a certain age(!), is:

To bring together, collect, gather or put up (corn etc) into a sheaf or sheaves.

The second is new to me:

To back a boat, to work the oars backwards. I have done this, but never guessed there was a word for it!

Regarding the first meaning; when the crop had been cut the reapers gathered and tied it, stem downwards, into large bundles, sheaves, or stooks, and left the bundles standing in rows of golden yellow pyramids across the field. A cart followed behind and the sheaves were picked up using a hay-fork and tossed onto the cart. The cart then took the crop to a suitable area for storage where, if it was for animal fodder, it was piled into haystacks. These were solid stacks of hay perhaps fifteen feet high and fifteen by thirty feet in plan and shaped like a house with a shallow sloping roof formed from the top layers of hay to shed the rain. I haven't seen this done since I was a boy; in fact I remember the first time I saw a field with rolls of hay across it, instead of the usual stooks, and being amazed at the mechanisation of the process.