Hi Lessic,
Yes, I'm Bulgarian and as you can see my English is far from the best. The translation, you've posted, is a good one. It was found that the both things are involved - darkness and Mracho (male name, that I've never heard before).
I'll make a try with my personal translation (nevertheless I'm "lost in translation"):
Don't you, darkness, benight me on this big field, (that was) ploughed 3 days by nine pairs of wild oxes, (because) when I return to the village, my mom will ask me: "With whom, Radka are you benighted? With whom, Radka, did you meet the down?". Mracho(???) says to Radka:" Say to her (to your mom), say to her: "Mom, I was benighted with (my) dear brother, (but) I met the down with (my) dear sweetheart (lover). If you come, mom, you'll see, (that) where we both (Radka and her lover) have lain, the wheat was reaped by itself and the sheaves were bound by themselves.""
Thanks for the links. I had a look at it and saw that this dance is called "Trakijska rachenitsa" (i.e Rachenitsa from Thrace). I suppose you know that Thrace is in the central and eastern part of Southern Bulgaria. I wish, I could dance it!
"Pozdravi" means greetings, regards (if I'm not wrong - "Salute " in Italian).
Ciao