Article Figures & Data
Tables
- Table 1.
A chronological summary of selected shade tree nitrogen nutrition field studies conducted in the United States during the 20th century. The publications have been grouped by author(s).
Year initiated Tear published Duration (years) Author(s) Species Spacing Treatment Selected findings Ground cover N rate (#) Method of application 1929 1929 NA* Beilmann NA NA NA NA NA Literature review. 1929 1934 5 Beilmann Fraxinus Juglans nigra Aesculus glabra Carya ovata Quercus palustris various sod 024–2.5/tree broadcast, crowbar, liquid injection Formula for fertilizer application based on tree volume; describes deep root feeding by liquid injection. 1929 1936 7 Beilmann same as 1934 various sod 0.24–2.5/tree same as 1934, trenching, post hole Same as 1934, 10-8-6 best fertilizer; fertilize before July 1, “shade trees cannot be overfed.” 1930 1936 5 Wyman Quercus palustris 12 by 12 ft sod 0.2/in.caliper broadcast, crowbar Ammon-phos better than ammonium sulfate; fertilized trees had more secondary growth than unfertilized trees. 1930 1937 7 Pridham Quercus palustris 12 by 12 ft sod not described not described Continuation of Wymann study; no fertilizer effects at age 7. 1934 1939 5 Pridham Ulmus americana not described sod 0.1/in/ caliper broadcast, drilled holes Decreasing growth with age; no response to fertilizer application. 1936 1941 5 Pridham Quercus rubra not described sod 0.13/in. caliper broadcast, drilled holes No clear tree growth response; delayed fall color development; sod growth luxuriant. 1931 1934 3 Chadwick Ulmus americana ‘Moline’ 8 by 12 ft none 36 lb/1,000 ft2 0.25 lb/in. caliper broadcast Limited fertilizer response, but fall application better than spring; adequate soil moisture needed for fertilizer response. 1931 1936 5 Chadwick Ulmus americana 8 by 12 ft none 0.25 lb/in. caliper broadcast Ample soil moisture seems more important for stimulating growth in good soil than additional application of fertilizer; fall fertilizer applications best. 1941 1950 7 Chadwick Acer platanoides 8 by 8 ft sod 1 /4 lb/in. caliper broadcast, punched holes, fertigator, Aero-fertil N most limiting nutrient; broadcast is best method of application. 1947 1962 4 Curlin Cornus florida single tree plots forest 0 to 297 lb/ac broadcast Two-year response to N application. 1959 1966 5 Finn and White Liriodendron tulipifera 25 tree plots on 6 by 6 ft Spacing weed 336 lb/ac broadcast Height increase 100%, diameter 85%, leaf color greener, delayed leaf abscission. 1956 1965 2 Neely, Himelick, and Crowley Quercus palustris Fraxinus americana Gleditsia triacanthos var. inermis 15 by 15 ft and 8 by 8 ft sod 61b/l,000ft2 broadcast, drill, liquid injection, foliar N applications stimulated growth; similar growth response to different application methods. 1956 1970 5 Neely, Himelick, and Crowley Quercus palustris Fraxinus americana Gleditsia triacanthos var. inermis 15 by 15 ft and 8 by 8 ft sod 61b/l,000ft2 broadcast, drill, liquid injection, foliar Continuation of 1965 study N applications stimulated growth; similar growth response to different application methods; April better than October for fertilizer application. 1972 1990 18 Smith Tilia cordata ‘Select’ Malus ‘Snowdrift’ Acer saccharum ‘Monumental’ 20 by 20 ft sod 0, 3, 6, or 9 lb/1,000 ft2 once per 3 years broadcast, drill Response to N fertilizer muted with age as did the effect of application method. ↵*Not applicable.