Interception of aerially applied ammonium nitrate by hardwood and softwood trees

Abstract

The quantities of ammonium and nitrate nitrogen (N) in stemflow and throughfall samples collected from hardwood and softwood stands were determined before and after aerial application of ammonium nitrate. Distribution of fertilizer reaching the ground during the aerial fertilization of the area was determined daily during the operation.Before fertilization, the concentrations of nitrate and ammonium N in stemflow and through-fall samples from both hardwood and softwood stands were negligible. Although more fertilizer prills per unit area were recovered in the hardwood than in the softwood stands, N levels in the stemflow and throughfall samples collected were higher in the softwood than in the hardwood stands. It was, therefore, concluded that the softwood trees intercepted larger quantities of aerially applied ammonium nitrate than did the hardwood trees.