We call them grass burs in these parts. (AKA sand burs.) The ones in the wiki links we call goat heads. The grass burs are hard to get rid of and don't respond to anything but a very expensive pre-emergent. (See link below.) And it doesn't work that well since you need to know where they are to treat the area. They'll pop up two feet away and the cycle starts over again. We've been battling them for the last 20 years here. About all you can do is mow short and mow often--Don't let them go to seed. If you have a grass catcher on a lawn mower, that helps to collect the seeds and you can dispose of that cycle. Keep your lawn in good health and it will eventually chook out the grass burs.
I've tried a lawn sweep and dragging old blankets around to collect them. Nothing works better than keeping the good grass healthy and mow, mow, mow.
And there's nothing you can do to keep them off tractor tires. Use a lawn mower in the area until you get them under control.
The scoop on grass burs:
Sandbur or Grassbur Control | Archives | Aggie Horticulture