Subject: How do I make a form of nitrogen, usable by plants

 I am doing research in my lab and need to know how to make nitrogen in 
the lab. The form must be compatible with potash and phosphorus so that I 
may apply to plants. I realize that it would be the easiest to buy, but I 
would like to know how to burn off the oxygen in the air  and have a 
usable form of nitrogen that is mixable with potash, phosphorus .  thank-
you 

Re: How do I make a form of nitrogen, usable by plants