Black horses drive a mower through the weeds,
And there, a field rat, startled, squealing bleeds,
His belly close to ground. I see the blade,
Blood-stained, continue cutting weeds and shade.
-"Reapers," Jean Toomer
In this passage from "Reapers" Toomer is lamenting the mechanization of farming that was rapidly taking place around him at the start of the 20th century. The "Black horses" deliver the connotation of the blacks horses, often associated with the Four Horsemen of the Apocalypse, indicates an extreme and lasting death, in this case, of nature. The idea of death is further pursued by Toomer by the graphic depiction of the death of the "field rat". In this sense Toomer is depicting the literal death of nature while also suggesting to the reader that this is just one instance of death and that the death of nature will continue because of the blades that "continue cutting weeds and shade."
Toomer also seems to feel a personal connection to the death of nature through the mechanization because of the use of the personal pronoun "I." Toomer uses this in the context of "I see the blade." He is actively seeing the death of nature and yet the speaker of the poem does not seem to be doing anything to stop this death, possibly because of the inevitability of the death as suggested again by the blades that "continue cutting weeds and shade."
Toomer also points to the irony of this death of nature through the use of the horses. The horses are the things pulling the mower through the weeds and causing the destruction of the rat, and in turn nature. As humans we are exploiting one part of nature, the horses, in order to destroy another part, the rat and the weeds.