Fluidized bed combustion residue from a calcitic limestone source (FBCRC), a by‐product of scrubbing SO2from fossil fuel fired boilers using the FBC technique was evaluated as a source of calcium for pecan (Carya illinoensis(Wang.) K. Koch) seedlings. Fluidized bed combustion residue produced following injection of calcitic limestone into the combustion chamber was more effective in neutralizing soil acidity and increasing extractable soil Ca levels than agricultural calcitic limestone. The Ca concentration in the pecan leaves was increased linearly by Ca rates for both 12‐ and 24‐week growth periods, but stem and petiole Ca concentration was increased linearly for the second 12‐week growth period. Macronutrient concentrations were affected by Ca rates for both 12‐ and 24‐week growth periods, but no effect was observed with Ca source. The primary difference was between the control and all other Ca rates. Leaf concentrations of Mn and Zn were decreased linearly by Ca rates and source for the first 12‐week growth period, but only by Ca rates for the second 12‐week growth period. Aluminum, Mn, and Zn concentrations in stems and petioles were generally reduced linearly during the second growth period by increasing Ca rates with r2values <0.4. Terminal shoot length was not affected by Ca rates or sources although cross‐sectional area was significantly increased by Ca sources for the first 12‐week growth period, and by Ca rates for both the 12‐ and 24‐week growth periods. FBCRC may be applied to pecan trees without any adverse affect on pecan nutrient or induced nutrient imbalances or toxicity from the heavy metals contained in the FBCRC.