Frost Folding

“The Winter Fields”
“Winds here, and sleet, and frost that bites like steel.
The low bleak hill rounds under the low sky.
Naked of flock and fold that fallows lie,
Thin streaked with meagre drift. The gusts reveal
By fits the dim grey snakes of fence, that steal
Through the white dusk. The hill-foot poplars sigh,
While storm and death with winter trample by,
And the iron fields ring sharp, and blind lights reel.
Yet in the lonely ridges, wrenched with pain,
Harsh solitary hillocks, bound and dumb,
Grave glebes close-lipped beneath the scrouge and chain.
Lurks hid the germ of ecstacy-the sum
Of life that waits on summer, till the rain
Whisper in April and the crocus come.”

What does this poem mean?
Who is the Author writting the poem about?
What is the theme of this poem?

Your help analyzing this wonderful poem is appreciated thank you!