Plant uptake of major and trace elements from soils amended with a high-calcium dry flue gas desulfurization by-product

- Increasing rates of a DFGD by-product increased plant tissue concentrations of nutrients and trace elements.
- Soil pH, and concentrations of nutrients and trace elements increased with increasing application rate.
- The high-Ca DFGD by-product used in this experiment was an effective nutrient source and liming material.
- Caution should be used to avoid over liming the soil and increasing tissue Se concentrations above limits deemed safe for grazing cattle.

Coal combustion by-products (CCBs) are a potentially valuable source of essential plant nutrients, but CCBs also frequently contain trace elements. The objective of this greenhouse study was to evaluate the effects of soil and application rate of a high-calcium (Ca) dry flue gas desulfurization (DFGD) by-product on Bermudagrass (Cynodon dactylon L.) growth and plant tissue and soil composition. Surface horizons of two soils with contrasting texture were mixed with a high-Ca DFGD by-product at rates of 0, 2.5, 5, 10, and 15 Mg ha−1. Bermudagrass was allowed to grow in the soils for 119 days. Concentrations of plant nutrients and selected trace elements were determined in soil and plant tissue. Plant dry matter and tissue concentrations of Ca, Mg, B, Se, Rb, and U increased as DFGD application rate increased. Concentrations of Mehlich-3-extractable soil P, Ca, Mg, S, Na, Fe, and B and strong-acid-extractable V and Hg increased with increasing application rate. Soil pH increased with application rate and electrical conductivity was only greater than that in the control at the 15 Mg ha−1 application rate after 119 days. The DFGD by-product used in this study can be beneficially reused as a soil amendment provided soil pH and plant tissue Se concentrations are closely monitored.