“while the tall grass fell behind the cutter bar in long green swathes”
-cutter bar: a cutter bar is a piece of equipment in some machines like harvesters, lawnmowers, or other machines used for cutting some material. The cutter bar is some kind of long bar which contains the blades normally.
–swathes (sing. ‘swath’): the grain or grass cut after the scythe or harvester has passed and which is left on the path in the field which is also called swath.
“Then the hay would be hoisted, sweet and warm, into the big loft ”
-loft: attic, storage place under the roof of a house