The speaker asks us to look at the ground, and then does something surprising: compares it to a sex organ. The comparison suggests that earth is both intimate and overwhelming, something we can neither hold onto nor let go of. "Too much to keep or to part with" captures that tension well. The ground is bound up with life and desire, and with the way we depend on it.
The second stanza softens the tone. The earth is "having almost a mind," as if it sits just short of consciousness, and it "has" rain that leaves the fields "sweet and full." The word "having" repeats, so the soil seems to possess and receive things the way a body does.
The mood is quiet, curious, and a little awed. The speaker doesn't sound shocked by the comparison. They sound fascinated, treating the land as alive, fertile, and slightly beyond understanding.