Boron accumulation by maize grown in acidic soil amended with coal combustion products

Coal combustion products (CCPs) have potential for use as soil amendments o n acidic soils. One concern for plants grown on acidic soils amended with C CPs is boron (B) toxicity, since many CCPs contain considerable B. Maize (Z ea mays L.) was grown (greenhouse) on acidic soil [Umbric Dystrochept, pH 3 .9 (1 soil:1 10 mM CaCl2)] amended with 15 CCPs [two fly ashes (FAs), three fluidized bed combustion products (FBCs), one calcium (Ca) oxide (CaO) mat erial, six high Ca sulfite (CaSO3) flue gas desulfurization products (FGDs) , and three high Ca sulfate (CaSO4) FGDs] at different levels to determine accumulation of B in shoots. Plants were also grown in soil amended with Ca carbonate (CaCO3, lime) and chemical grade CaSO4 and CaSO3 as controls. Am ong the CCPs tested, FAs contained the highest B levels. Shoot B concentrat ions were as high as 500 mg kg(-1) without reductions in dry matter (DM) fo r plants grown on soil amended with one FA. Plants grown with one FBC had s ufficient B to suspect potential B toxicity, and plant DM was greatly reduc ed or died when grown with > 0.5% of this material. Relatively high shoot B concentrations were noted in plants grown with the highest levels of high CaSO3 FGDs. High shoot B concentrations (similar to 300 mg kg(-1)) were not ed for plants grown with > 5% levels of one high CaSO4 FGD, and DM declined after reaching these levels. Plants grown on soil amended with CaO had low shoot B. Some of the CCPs used in this study contained sufficient B to pot entially induce B toxicity in plants grown on the acidic soil amended with the various CCPs. Maize growth was generally enhanced when grown on soil am ended with the CCPs at appropriate levels. Published by Elsevier Science Lt d.