If you are wanting to work with nature and landscape, you will find the 50mm prime to be both too limiting and not wide enough on a DX body. For a starter lens with this kind of photography (which I primarily do myself) you will get much more mileage on a "superzoom" style lens as you learn. Nikon 18-300mm (more expensive) or Tamron 18-270mm (not a bad choice and less expensive) would be on my short list. I use the Tamron 18-270mm a lot. If you don't work at the extreme ends of the zoom, the optical artifacts are controlled.
When I started checking on my compositions after some time, I found I was shooting in the 25mm-35mm range more often than not. But the long reach of the zoom is good for the occasional animal you get opportunities to shoot. And you will find subjects like sunrises/sunsets work better on a longer zoom to give the illusion of a larger sun. Really the first prime lens I would recommend for a DX body is the Nikon 35mm DX f1.8. It is a "normal" on a DX body and works great for candid indoor photography as well as some landscape photography in lower light settings.