This is very good work.  I really thought it was written by someone who served and was a prisoner in WWII until I looked at your profile.  Your character comes across as quite real.

  Instead, the sentence is deemed to be that of limbo – a purgatory worse than the everyday hell. No longer is he relying on his own skill and luck combined with that of his company, but he is at the will of the enemy and their observance to rules and conventions.  There is no longer a gun in his hands, but rather a shovel instead. He has left one field to travel through another and end up in a third, even though they are worlds apart. An impoverished West Virginia breaking its back in fields of coal has given way to the equally broken fields of Europe where first he aimed to bury rather than uncover and now is digging for potatoes in the hard and rocky German soil.

         I had a little trouble understanding that your MC is a prisoner of war in this paragraph.  Although I like the descripton  of limbo - a purgatory....  and I'm not sure I follow all three of the fields your MC has traveled. 

In your last paragraph you allude to your MC getting sick and dying after twenty five years.  I'd like to know more about his illness  Is it mental or physical?  I think it would be interesting to read how he fared after his imprisonment.  I once knew a man who was a Korean War vet and he wouldn't eat rice if it was the last food on earth.  Then of course we have John McCain, the epitomy of  war hero.

I really like this work.  You've written a piece that many people across a spectrum of ages can and will relate to.  War does indeed change people and it also affects and in many ways changes the people they love.

I would really like to read more from this character.

Thanks for writing and sharing it so close to Memorial Day.    

and he prays that his gaze rests on his final destination because hell can’t be worse than here and now

This line felt a little obscure to me because it's an abstract idea rather than a clearcut image.

Agonizingly, as if in slow motion, he raises himself from the ground and further observes his surroundings.

This early in the story, I would rather "He stood up."

The men he has come to know in the previous months and years are either mimicking his cautious actions or lying broken on the earth. Shielding his eyes from the sun he stands and moves with his company as they leave those lost and proceed toward their own precarious fate.

It's written competently, but for clarity's sake I would simplify this so that the reader gets clear visual images in his/her mind, especially since we're in the first paragraph.

His hands are shaking as they grip the rifle he carries, and he cannot remember the last time they were still.

I'd recommend shorter sentences. A period after "carries." This is just a stylistic preference of mine, but given the tone of this story and the state of mind our protagonist is in, I think it's more appropriate to have shorter, simpler thoughts.

Every movement, every sound inspires fear and contemplation.

...a line like this removes intimacy. We know it's being written much later from an omniscient author. It's your choice, but I think it would evoke more emotion in the reader if we experienced it through the protagonist. "His heart pounds, his senses alert, leaping at the slightest movement or sound." Since it's written in present tense, the reader expects it to be happening, now, rather than past tense "Every moment, every sound inspired fear and contemplation" which lets us know it happened a long time ago.

This may be the end with death imminent, or it might be yet another temporary respite in a long chain of chances that could culminate in permanent safety. Days pass, rife with thousands of these soul wrenching, heart stopping sounds until those chances finally seem to end. However, the death that appears so imminent does not come. Instead, the sentence is deemed to be that of limbo – a purgatory worse than the everyday hell. No longer is he relying on his own skill and luck combined with that of his company, but he is at the will of the enemy and their observance to rules and conventions.

This exposition is perfectly appropriate for an elegy. I'm not sure exactly what you're going for. But it doesn't really "put me into the moment," if you get what I mean.

There is no longer a gun in his hands, but rather a shovel instead. He has left one field to travel through another and end up in a third, even though they are worlds apart. An impoverished West Virginia breaking its back in fields of coal has given way to the equally broken fields of Europe where first he aimed to bury rather than uncover and now is digging for potatoes in the hard and rocky German soil.

I'd pare this down for clarity, but the digging for potatoes concept is really interesting.

The sounds that stirred such fear in the past are yearned for as silence has become the norm, and interminable waiting the only thing to look forward to. Hope has all but gone. Hope of rescue, hope of peace, hope of home.

I think this can be cut.

The "Red Cross" line is good, because it evokes a familiar image.

Responses are made and assurances of health given; white lies to give comfort to those safe and ignorant.

Would this soldier really be aware of this? Or are we are of this simply because we look back at it in history? I think soldiers in WWII would've trusted the Red Cross and their government.

Two years have passed. Two years of shovels and dirt, potatoes and brown bread, dirty water and more German and Italian than he has ever heard. Sometimes the sun will shine, casting a rosy hue over the landscape. The irony that beauty can exist in such a broken and bleak reality is not lost on him, despite his Eighth grade education. He prays in the morning, to get through one more day, to find that all hope has not evaporated. When resignation has all but set in, and faith is nearly gone the tides change and Russian voices enter the fray. Saviors have arrived, and although the journey is not done, the Atlantic is beckoning.

I think this paragraph needs some setting. Otherwise the reader might unwittingly assume the narrative is leaping in time. "He recalls the two years that have passed" would at least let us know he's pausing for a moment to think. As it is now, these thoughts are being 'told' to us by the narrator with no context of when it's being thought.

His hands will stop shaking and his strength will return. Laughter will be possible again and the sunshine will not be rued for existing. The images will never fade, however, of those that were broken and abandoned. The roar of the explosions and bullets will forever haunt him. Potatoes will disgust him, and brown bread makes him pause. The permanent safety he thinks he has found, however, will prove to be only an illusion. The battle will never end and although one foe has been overcome, after 25 years another will breed from within, perhaps because of that dirty water, perhaps not. His chances will end, and death will come.

Some of the words like "broken, abandoned" "roar, explosion, bullets, battle" however pertinent here feel somewhat cliched. We know it's war. We've read about it before. I think this could stand some editing out of those familiar words describing war, not because they're not important but because it's unnecessary. There's an expression in music that goes, "Listen to the notes he's not playing." The same goes here.

Also, the really fascinating part of this is the potatoes and brown bread, the dirty water! That's powerful stuff. Since your title is "Digging for Potatoes," I think it could use some "you-are-there" descriptions to evoke the feeling that the reader is there, in the skin of this soldier, digging for potatoes out of sheer hunger and desperation.

Hope this helps.