Beyond personal preference and convenience, choice of liquid or solid sources of nitrogen depends mainly on the costs of materials, or application itself and of any application and storage equipment necessary.
Heady, Earl O.; Smith, Wesley G.; and Stritzel, J. A.
"What Cost for Liquid or Dry Nitrogen?,"
Iowa Farm Science: Vol. 13
, Article 8.
Available at: https://lib.dr.iastate.edu/farmscience/vol13/iss1/8