Thanks, Susanne, that makes it sound better.
I took "Feld" as meaning that the field which they knew became the battleground red with blood. After it was over, the poppy was again blooming there.
At the last, the interpretation bothered me. Marie Marei, bid be goodnight, sadness will soon be forgotten- did he die in the field (his fortuna)? Then, the other stanza, returning back "to you" would not be right. (I think I am reading more into it than is there).