Sentence:  Part of your job would be to learn tractor ploughing and the use of planters, <WSD>harrows</WSD>, and cultivators. 
Meaning of the word marked with <WSD> tags:  A device consisting of a heavy framework having several disks or teeth in a row, which is dragged across ploughed land to smooth or break up the soil, to remove weeds or cover seeds; a harrow plow.