Textures do not render in not so long distances,Textures do not render in not log distances

Hi im developing a minecraft-like game from scratch. Im using a Ulint/Texture material with an atlas, and in the runtime i add uvs to mesh. The problem is the texture is not being displayed as expected in distance. In this picture the ground should be all bedrock, but as you see it is rendered brown a little distanced from the camera! Note that the texture is being displayed correctly on the dirt blocks that are not on the ground level. also if i jump the viewport on the ground gets extended. Right now to hide this brown area i am using a heavy fog, but that needs to be too heavy to hide this issue!

Is there a way to increase this viewport?