Image Processing - Cleaning up

Hey Guys! I was trying to segment the crops from the soil as seen in the following image('Segmentation.JPG').

I tried using a median filter to clean up the noise but I am not able to get a clear distinct segmented image.

This is the best I could get after using a median filter('median_filter.jpg')

How do I go about achieving a clear segmented image something of this sort? ('clear_segmented.jpg')