Besides nitrogen fixation what other process can be used to strip/capture nitrogen from the atmosphere.

You can do it biologically (I think that's what you're referring to by "nitrogen fixation"), or chemically -- as in synthetically creating ammonia (the Haber-Bosch process). Any reaction involving nitrogen gas will "fixate" nitrogen.

Well, there are quite good information from this site:

The Nitrogen Cycle (http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/NitrogenCycle.html)