Pulse crops, or grain legumes, have become an important rotational crop in the Great Plains region. While consumption of these crops is low in the region, their international demand as human and livestock food have provided farmers with an excellent marketing opportunity. Environmental conditions in the Great Plains region support successful production of these crops, with minimal disease damage to the harvested seed. Health benefits from consuming grain legumes come from the substitution of a plant protein for animal protein. An interesting agronomic characteristic of grain legumes is their nitrogen (N) fixation capability, and ability to grow for the most part in the absence of added fertilizer N. The crops not only fix most of their N requirements, but crop residues high in N reduce N immobilization, build soil microbial communities, and increase N supply to subsequent crops in rotation. Understanding the role of N fixation in crop production, residual nutrients and greenhouse gas emissions will be reviewed.