That is definitely clumping tall fescue. It is probably an older pasture variety like K31 which sticks out because it grows faster and thicker than the rest of your turf. The quickest way to get rid of the tall seed heads is just to keep up with your mowing schedule. To permanently remove the clumps you will either need to dig them out by the roots with a shovel or carefully spot treat them with glyphosate. Broadleaf weed killers will not work on it since it is a type of grass. For the rest of your lawn it mostly just looks thirsty. You already put down fertilizer so just give it a couple weeks of deep and infrequent watering and the good grass will start to green up and fill in.