Nutrient Uptake and Removal by Christmas Tree Harvest

Writing nutrient management plans for Christmas tree production requires accurate values for nutrient removal and harvest records.  To obtain such data, freshly cut trees were collected from several commercial plantations in New Jersey.  A total of nine market-size trees consisted of thee trees per each of   Norway spruce (Picea abies ), Canaan fir (Abies balsamea var. phanerolepis), and  Douglas fir  (Psuedotsuga menziesii).  Minimum, maximum, and mean cut tree size measurements were as follows for height (m): 1.98, 2.69, and 2.33, respectively; basal diameter (m): 1.30, 2.72, and 1.66, respectively; volume (m³): 0.87, 4.88, and 1.83; area (m²): 1.28, 3.43, and 1.96; fresh weight (kg/tree): 5.23, 51.29, and 21.98, respectively.  Mean tree moisture content at harvest was 53.89%.  Three whole tree plants per species were cut into smaller pieces, oven-dried, and ground for determining dry weight, nutrient concentration, and nutrient removal per given area. Nutrient contents were calculated for whole trees and there were no significant difference in nutrient uptake values among species.  Assuming a tree row spacing and within row spacing of 1.5 m x 1.5 m for a population of 4,302 trees per ha, a clear cut harvest would be projected to remove on average (kg/ha) 560 N, 60.87 P, 168 K, 243.51 Ca, 37.75 Mg, 28.25 S, 0.54 B, 3.39 Fe, 4.74 Mn, 0.11 Cu, and 2.79 Zn, 2.92 Al, 105.85 Cl, 0.02 Mo, and 1.44 Na.  Nutrient removal estimates for wider row spacing can be recalculated based on the number of trees harvested from a unit land area.  Cities that collect Christmas trees after the holiday and shred them for mulch may also find the nutrient content values useful.