FLY ASH-AMENDED COMPOST AS A MANURE FOR AGRICULTURAL CROPS

Homemade organic compost prepared from lawn grass clippings was amende d with fine fly ash collected from a coal-fired power plant (SRS 484-D , Savannah River Site, Aiken, SC) to investigate its usefulness as a m anure in enhancing nutrient uptake and increasing dry matter yield in selected agricultural crops. Three treatments were compared: five crop s (mustard, collard, string beans, bell pepper, and eggplant) were eac h grown on three kinds of soil: soil alone, soil amended with composte d grass clippings, and soil amended with the mixed compost of grass cl ippings and 20% fly ash. The fly ash-amended compost was found to be e ffective in enhancing the dry matter yield of collard greens and musta rd greens by 378% and 348%, respectively, but string beans, bell peppe r, and eggplant did not show any significant increase in dry matter yi eld. Analysis of the above-ground biomass of these last three plants s howed they assimilated high levels of boron, which is phytotoxic; and this may be the reason for their poor growth. Soils treated with fly a sh-amended compost often gave higher concentrations than the control f or K, Ca, Mg, S, Zn, and B in the Brassica crops.