Lots of grass growing on 2nd year alfalfa please help

Okay so one of my buddies planted some round up ready alfalfa last fall and it started off yielding good nice hay but this season more and more grass has been popping up over the alfalfa and not letting it regrow properly. What should i suggest he should do about this problem? What can he spray to make the alfalfa come back? It's only the 2nd year of it and it has tons of grass. Thanks for the advice in advance

Lots of grass growing on 2nd year alfalfa please help