Effect of land application of fluidized-bed combustion residue on soil and plant characteristics of reclaimed surface-mined pastures, performance and mineral status of grazing steers and nutrient balance by sheep fed the forage

Fluidized-bed combustion residue (FBCR) results from mixing coal with limestone during the combustion process. This by-product may be used as a liming agent. A grazing trial was conducted on an acidic mine soil to compare FBCR to dolomitic limestone and no amendment (control). Six steers per treatment were grazed rotationally on three replications (rep) of three .8 ha pastures. Both materials increased soil pH similarly, and reduced plant uptake of Fe, Zn, Mn, and Ni similarly. Calcium concentration increased in forages by both amendments, Mg increased with limestone and S with FBCR application. Cell wall components decreased, while ash and lignin increased with both amendments. Serum mineral levels of cattle were normal except Cu was low. Animal tissues reflected differences in mineral concentration observed in forages. Hay harvested from one rep was used in a mineral balance trial with 18 wethers. Apparent digestibility of dry matter, crude protein and fiber components, and N retention were not affected by treatment. Control animals were in negative Ca balance. Apparent absorption of Mg was higher (P < .01) for limestone treatment animals; S absorption was higher for the FBCR group; and, Zn absorption was higher for controls. Serum mineral levels of sheep were normal except Cu was low. No appreciable accumulation of heavy metals occurred in forage or animal tissues. Low Cu levels observed for all treatment groups indicate a problem inherent of the study site. FBCR appears to be a safe and efficient soil pH amendment.