I have some textures for you that might help.
A "Plank" Texture.
This texture is 512px X 512px so it's a little small but I've used it for everything from docks to wooden floors.
A "Road" Texture
This is also 512 X 512 but is one of my favorite "dirt" textures as it has just a little grass in it to differentiate it from a "gravel" road. I hope you can use these and Good Luck.