Download Dry Grass and Mud Photo-Texture Free Unity. 

10 HQ (Smoothness(A)) Photo-Texture Dry Grass and Mud for the standard Unity Terrain.
All textures seamless with a resolution of 2048×2048 .Albedo texture formats TGA(Smoothness(A))
Normal map formats PNG
Textures made specifically for the terrain shader Unity(Built in Standard Metallic)
Textures are aimed to create AAA quality games