Why should any crop rotation include a leguminous crop?

Leguminous crops are desirable in crop rotation because they contain a bacteria called rhizobium in their roots which help in fixing nitrogen in the air and break it down into nitrates and nitrites, which provides nutrients to the plant and also helps the soil in regaining its fertility.

The limitations of forensic drug chemistry is (1) they cannot create drugs out of wht they learned in chemistry although they can create one, (2) theire line of expertise is limited to the illegal drugs and crime committed acts.