RT Journal Article SR Electronic T1 Fertilization and Other Factors Enhancing the Growth Rate of Young Shade Trees JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 33 OP 37 DO 10.48044/jauf.1981.009 VO 7 IS 2 A1 Hendrik van de Werken YR 1981 UL http://auf.isa-arbor.com/content/7/2/33.abstract AB Shade tree research at the University of Tennessee, Knoxville, Tennessee showed that non-established, bare-root planted, shade trees did not respond to nitrogen fertilization but responded vigorously after establishment. Phosphorus and potassium levels above medium did not significantly increase growth. Growth rate increase due to nitrogen applications did not affect wood density and fiber length. Trees grown in high density groves and mulched with pea gravel on plastic had a higher growth rate than those in low density groves with grass as groundcover. Survival of bare-root transplanted shade tree species was not determined by type and amount of fertilization nor by method of application. On phosphorus deficient soils slow release 14-14-14, applied broadcast, gave a higher growth index for 5 out of 6 species tested than 14-14-14 applied in holes. Application of 20-20-20 soluble fertilizer was less effective. On soils containing sufficient phosphorus, surface application of nutrients was more effective than subsurface application while ammonium nitrate and 20-20-20 were equally effective.