TY - JOUR T1 - Comparison of Trunk Injected and Soil Applied Macronutrients JF - Arboriculture & Urban Forestry (AUF) SP - 322 LP - 324 DO - 10.48044/jauf.1991.071 VL - 17 IS - 12 AU - E. Thomas Smiley AU - Bruce R. Fraedrich AU - Donald C. Booth Y1 - 1991/12/01 UR - http://auf.isa-arbor.com/content/17/12/322.abstract N2 - Macronutrients (N,P,K,) deficient willow oaks (Quercus phellos) grown in parking lot islands were fertilized by trunk or soil injection. Foliar nitrogen levels improved significantly in soil fertilized trees. Foliar color improved most in the soil fertilized trees and not at all in the controls. ER -