GROWTH AND ELEMENTAL COMPOSITION OF CORN AND BEAN SEEDLINGS AS INFLUENCED BY SOIL APPLICATION OF COAL ASH

Analyses of 0.1 N HCl extracts of ash (slag + fly ash) samples from bituminous coal revealed high concentrations of K, Ca and Fe and intermediate concentrations of P, Mg, Cu, Mn and Zn. Of the elements analyzed, the extractable concentrations increased as particle size decreased from > 1000 .mu.m to < 105 .mu.m. The slightly acidic ashes were mixed with Troup sandy loam (Grossarenic Paleudults) at rates of 5, 10 and 20% (fine ash) by weight and equilibrated in a glasshouse for 1 mo. before planting. Coarse ash was used at only the 10% rate. Corn (Zea mays L.) and bush bean (Phaseolus vulgaris L.) yields from ash-amended soils were statistically equal to yields from a control treatment (no fertilizer or ash added) but significantly lower than fertilized (N-P-K) treatment. Corn exhibited P deficiency symptoms while symptoms characteristic of B toxicity occurred in beans. Analyses of tissues of both crops indicated that P concentrations were at deficiency levels while Cu, Mn and Zn were deficient to marginal. Fe, however, apparently was in the normal range. Salinity as indicated by EC [electrical conductivity] of leachate of 3 mmhos/cm or greater, B excess as indicated by the toxicity symptoms in beans and P deficiency as indicated by low P concentrations in plant tissues could limit crop growth in ash-treated soils.