Sorry this is for Shep, but here's my opinion. To me, it looks really un-uniform and just doesn't seem to flow well with the track itself and the grass thins and thickens too much in places. It really can use some improvement, but to start, it's not bad.
Its looking good, but try to make it flow a little more. As it is right now it's very concentrated into certain lines and i think it'd benefit if you blended it out a little more!