HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Figures Only Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (28) Citing Articles via Google Scholar Google Scholar Articles by Adriano, D. C. Articles by Weber, J. T. Search for Related Content PubMed PubMed Citation Articles by Adriano, D. C. Articles by Weber, J. T. GeoRef GeoRef Citation Agricola Articles by Adriano, D. C. Articles by Weber, J. T. Related Collections Industrial Waste Soil Chemistry

TECHNICAL REPORT
WASTE MANAGEMENT

Influence of Fly Ash on Soil Physical Properties and Turfgrass Establishment

The Univ. of Georgia, Savannah River Ecology Lab., Drawer E, Aiken, SC 29802

Corresponding author (Adriano{at}SREL.edu)

Received for publication May 17, 1999.

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION GENERAL DISCUSSION REFERENCES

 
A field study (1993–96) assessed the benefits of applying unusually high rates of coal fly ash as a soil amendment to enhance water retention of soils without adversely affecting growth and marketability of the turf species, centipedegrass [Eremochloa ophiuroides (Munro) Hack.]. A Latin Square plot design was employed that included 0 (control, no ash applied), 280, 560, and 1120 Mg ha^-1 application rates of unweathered precipitator fly ash. The fly ash was spread evenly over each plot area, rototilled, and allowed to weather under natural conditions for 8 mo before seeding. High levels of soluble salts, indicated by the electrical conductivity (EC) of soil extracts, in tandem with an apparent phytotoxic effect from boron (B), apparently inhibited initial plant establishment as shown by substantially lower germination counts in treated soil. However, plant height and rooting depth were not adversely affected, as were the dry matter (DM) yields throughout the study period. Ash treatment did not significantly influence water infiltration rate, bulk density, or temperature of the soil, but substantially improved water-holding capacity (WHC) and plant-available water (PAW). Enhanced water retention capacity improved the cohesion and handling property of harvested sod.

Abbreviations: CCP, coal combustion by-product • DM, dry matter • EC, electrical conductivity • PAW, plant-available water • WHC, water-holding capacity

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION GENERAL DISCUSSION REFERENCES

 
THE use of coal to produce electric power or heat requires large quantities of coal annually. In the USA, coal is the most extensively used and most important source of energy, and will probably continue to be so. The production of coal combustion by-products (CCPs) was 68 million Mg in 1983; production for 1997 was at about 97.5 million Mg and is projected to increase (American Coal Ash Association, 1998). The three general types of ash produced are fly ash, bottom ash, and boiler slag (Carlson and Adriano, 1993). Another CCP is flue gas desulfurization (FGD) residue produced by scrubbers to remove greenhouse gases, including sulfur dioxide (SO₂), during coal combustion. Currently, the most widely accepted disposal practices for fly ash are landfilling, stockpiling, and storage in settling ponds. In 1997, only 32% of fly ash was used (American Coal Ash Association, 1998). Main uses of fly ash include partial substitution in cement mixes, roadfills, and bases, and waste stabilization and solidification. This low usage rate ensures vast amounts of fly ash accumulating on land surfaces and therefore interacting with the environment.

The mineralogical, physical, and chemical properties of fly ash depend on the nature of the parent coal, conditions of combustion, type of emission control devices, and storage and handling methods. Thus, anthracite, bituminous, and lignite coals produce ashes of different compositions. Combustion temperature influences the degree to which many mineral elements may volatilize. Storage methods may affect weathering rates, especially under humid conditions where soluble constituents may be leached (Straughan et al., 1978; Adriano et al., 1980). The various mineralogical, physical, and chemical properties of fly ash have been comprehensively reviewed (Fisher et al., 1978; Page et al., 1979; Adriano et al., 1980; Carlson and Adriano, 1993).

Fly ash is a heterogeneous mixture of amorphous and crystalline phases and is generally considered to be a ferroaluminosilicate mineral with Al, Ca, Fe, K, Na, and Si as predominant elements (Adriano et al., 1980; El-Mogazi et al., 1988; Mattigod et al., 1990). Particle size greatly influences chemical composition of fly ash and how it may affect physical properties of soil.

The pH of fly ash can vary from 4.5 to 12.0 depending largely on the S content of the parent coal (Plank and Martens, 1974). Eastern U.S. coals that include anthracite are generally high in S and produce acidic ashes, while western U.S. coals, which include lignites, tend to be lower in S and higher in Ca and produce alkaline ashes (Bern, 1976; Furr et al., 1977; Page et al., 1979; Natusch et al., 1975).

Because of the stagnating usage of CCP, research is now addressing new usage options that could utilize a greater percentage of fly ash produced. Large-scale application on land has been advocated as a promising utilization option. Fly ash has been demonstrated to be effective in reclaiming acid mine spoils (Capp and Spencer, 1970; Fail and Wochok, 1977). The quantities of fly ash used in mine spoil reclamation can far exceed those suitable for cropland application. Because of the liming potential of certain fly ashes and their ability to provide essential nutrients for plant nutrition, fly ashes are being considered for amending agricultural soils to improve both chemical and physical properties (Clark et al., 1995; Nass et al., 1993; Phung et al., 1978; Schwab et al., 1991; Sikka and Kansal, 1995). Reported benefits of adding fly ash to problem soils include improved soil structure for coarse or fine textured soils, improved WHC, and increased pH in acidic soils (Chang et al., 1977, 1989; Carlson and Adriano, 1993). Because of the dominance of silt-size particles in fly ash, this material may often be substituted for topsoil in surface mine lands, thereby enhancing physical conditions of soil, especially WHC.

A number of soil physical properties have been enhanced by the use of fly ash with a concommitant increase in aeration and reduced bulk density from its application of silt-sized particles (Chang et al., 1989). Although enhancement of WHC of some soils has been reported due to fly ash application, it is still unclear whether this beneficial effect translates directly into increased availability of water for plant use. However, banding of ash into a field soil at a 45° angle to the surface produced increases in corn (Zea mays L.) yield, apparently due to increased WHC of ash-banded soils (Jacobs et al., 1991).

Because application of certain fly ashes, especially at high rates, can affect the quality of plant materials and the food chain in general, other application options should be explored. This includes non–food chain areas, such as turf (sod) farms.

The pressure to explore other innovative application and/or disposal options is exacerbated by the ever-increasing expense of disposing and managing fly ash, where the cost may range from $2.43 to $37.64 Mg^-1 (USEPA, 1988). The cost is primarily associated with the ever-escalating cost of constructing new, state-of-the-art landfills. Because of limited use of fly ash on land, about 70% of power generating facilities use landfilling and impoundment as disposal techniques.

Mixing Class F fly ash with topsoil could enhance soil physical properties, especially those either in the clayey or sandy range. In essence, this is creating a new, synthetic soil with enhanced soil–plant–water relations. This strategy could be applied to severely eroded areas or in sod farms where substantial amounts of topsoil can be lost from harvesting operations of grass. In 1992, the growing demand for turf grasses from both residential and business owners resulted in 88355 ha of sod being harvested in the USA, up by 19% from 1987 (USDA, 1997). Such harvesting removes substantial amounts of fertile topsoil from turf fields. For example, 1992 figures indicate that nationally, an annual loss of between 12 and 15 million Mg of topsoil occurs due to sod harvesting. Depleted topsoil needs to be replaced to sustain favorable root environments for future plants.

It is the potential benefits of using unusually large amounts of fly ash that compelled us to explore the possibility of using sod farms as an application venue. The objective of this study was to evaluate the horticultural benefits of applying large amounts of fly ash on sod farms in terms of enhanced physical properties, and to some extent, chemical properties of soil, and more specifically to (i) quantify the effects of fly ash on certain physical properties of soil, including bulk density, infiltration rate, soil temperature, WHC, and PAW and (ii) evaluate effects of high application rates of fly ash on plant germination and initial establishment.

	MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION GENERAL DISCUSSION REFERENCES

 
A field study was begun on 12 July 1993 by establishing a Latin Square design of four treatments (0 [control], 280, 560, and 1120 Mg ha^-1 of coal fly ash). The research area was 1466 m². Each treatment plot (subplot) was 46.5 m², with 3.6 m between each subplot. Ash was piled and spread to the desired thickness for each subplot, then tilled in with a rototiller. Samples of fly ash for analysis were taken from each subplot before tilling. The entire plot was seeded with centipedegrass at a rate of 11.2 kg ha^-1 and rolled for better seed and soil contact. After the initial planting on 14 July 1993, very little germination occurred on the 1120 Mg ha^-1 treatment. This was probably due to insufficient mixing of ash and underlying soil. This probably resulted from the ash desiccating over the 3-d process of establishing subplots to create a powdery ash that could not be tilled adequately into soil. Consequently, plots were retilled on 1 April 1994, reseeded at the same rate, and rolled. After "greening up" each spring, 24 kg ha^-1 of N as 34–0–0 (34% N, 0% P₂O₅, 0% K₂O commercial fertilizer) were applied on plots every 6 wk, three times annually.

The fly ash used in this experiment was from a pulverized coal fire unit burning eastern Appalachian bituminous coal (Type F). The fly ash was conditioned and collected using electrostatic precipitators and stored in a silo. The fly ash delivered to the research area was taken directly from the silo. Soil at the research plot was Congaree silt loam (fine-loamy, mixed, active, nonacid, thermic Typic Udifluvents) with less than 1% slope, well drained, and moderately permeable.

Soil samples were collected throughout the experimental period (22 June 1993, 9 Aug. 1993, 8 Mar. 1994, 22 Feb. 1995, and 8 July 1996). After samples were collected, they were air-dried and passed through a 2-mm sieve. For certain parameters (e.g., bulk density) samples were also weighed (Gardner, 1986), and temperature, EC, and pH (1 solid to 1 water) were obtained in the field using a multirange conductivity meter and a pH/ISE/mV meter with temperature probe.

Field capacity was obtained by saturating plots and allowing them to drain freely for 48 h. Shallow soil samples (0–15 cm) were collected from each subplot, sealed in a zip-lock bag, weighed, air-dried, and weighed again. Percent moisture was calculated (Cassel and Nielsen, 1986).

Bulk density was calculated using a soil sampler of known volume to collect intact soil cores, which were oven-dried and weighed (Blake and Hartge, 1986).

Plant-available water (PAW) was determined by placing intact saturated soil cores on porous plates. A series of pressures were applied for stabilization of 1 wk at each pressure. The PAW was obtained by weighing soil masses at each pressure and calculating the volumes of each mass. An infiltration ring (1.2 m diam.) was employed to determine steady state infiltration rates (Bouwer, 1986). Rain and irrigation water was recorded using weighing buckets, strip chart recorders, and rain gauges. Statistics were obtained by using PC SAS Version 6.12 for Windows TS020 for one-way ANOVA and Tukey's means separations (SAS Institute, 1990).

	RESULTS AND DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION GENERAL DISCUSSION REFERENCES

 
Effect of Fly Ash Application on Selected Soil Properties
The fly ash used in this study had a pH of 7.98 to 8.06 and EC of 2.37 to 3.35 dS m^-1. Unburned organic carbon in the fly ash was considered soil organic matter (Table 1A). Significant increasing amounts of soil organic matter from 0 to 1120 Mg ha^-1 fly ash rates were due to unburned coal in the fly ash and not due to buildup from decay of centipedegrass plant debris (Table 1A). The most significant differences occurred in the 0- to 15-cm layer of soil.

Apparently, fly ash application did not induce any measurable increase in soil temperature in spite of visual darkening of soil color (Table 1C). Dark-colored soils are expected to absorb more radiant energy than light-colored soils, as in the case of low organic matter–sandy soils.

The primarily silt-size prevalence of the fly ash used evidently enhanced PAW and WHC of soil. The large surface area of spherical-shaped fly ash particles is conducive to increasing microporosity of soil, thereby enhancing soil air space, which is tantamount to soil WHC. In addition, some spheres are hollow (i.e., cenospheres) while others (i.e., plerospheres) are filled with smaller amorphous particles and crystals (Adriano et al., 1980), enhancing the microporosity of treated soil. The increase in WHC became significant with the 560 Mg ha^-1 rate of fly ash (Fig. 1) whereas PAW on average became significant only at the highest rate of 1120 Mg ha^-1 (Table 2).

View larger version (32K): [in this window] [in a new window]   Fig. 1. Percent moisture of soil at field capacity (FC) as influenced by the addition of different rates of fly ash. Bars not sharing the same letter are statistically different at P < 0.05 by Tukey's test

Effect of Fly Ash Application on Initial Establishment and Dry Matter Yield of Grass
After planting on 1 Apr. 1994, germination counts of the grass were conducted on four different dates. No significant differences were noted among treatments on the 28th day after planting, indicating the slow germination characteristics of this species (Table 3A). By the 35th day after planting, germination significantly improved for the control and the 280 Mg ha^-1 rate over the two highest rates (560 and 1120 Mg ha^-1). The detrimental effects of high rates of fly ash on germination lingered through the 43rd and 57th days after planting. Apparently, the high EC of the fly ash (i.e., 2.37–3.35 dS m^-1) in treated soil, especially at the two highest rates, was detrimental to germination of this species. For grass species, EC values higher than 3.0 dS m^-1 (3.0 mmho cm^-1) in soil solution, may hinder plant establishment due to increased osmotic potential and salinity (Maas, 1990).

	GENERAL DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION GENERAL DISCUSSION REFERENCES

In addition to enhancing the alkalinity and buffering capacity of soil, one of the most important features of fly ash is its beneficial effect on physical properties of soil. Chang et al. (1977) reported that the texture of fly ash resembles that of silty and loamy soils. The WHC of soils with different texture has been shown to be positively correlated with percentage of fine sand (0.02 to 0.2 mm) and organic C, and negatively correlated with percentage of coarse sand (0.2 to 2 mm) (Salter et al., 1966). Because of the dominance of silt-size particles in the fly ash we used in our study (60%), water-retention capacity in sandy soils and plant–soil–water relations in clayey soils should be enhanced. The WHC and PAW (defined as the amount of water that a soil mass can release between field capacity [0.033 MPa] and permanent wilting point [1.50 MPa]) of the Congaree silt loam in this study were substantially enhanced by fly ash, although the infiltration rate was not improved. In addition to treated soil being less susceptible to drought, the soil held together better when the grass was harvested, a desirable feature that enhances marketability of sod. The latter phenomenon can be attributed to the pozzolanic (ability to cement or aggregate particles) nature of the ash (Table 5).

Unusually high rates of fly ash, ranging from 448 to 1792 Mg ha^-1, incorporated to a depth of 76 cm, substantially increased the amount of soil moisture of two coarse-textured soils by 25 to 70% (Jacobs et al., 1991). The yields of field corn used in their study were consistently increased over controls, due to increased PAW where fly ash bands had been applied. In drought-prone soils (i.e., coarse-textured soils) or soils that exhibit water ponding, fly ash application may induce permanent physical modification of the soil that potentially could increase plant yield. On the Mason Farm, where our study was conducted, sod harvesting usually removes approximately 1 cm of ashed soil annually. Thus, enhanced water retention capacity of treated soil should linger for about 15 yr (i.e., corresponding to the 0- to 15-cm treated depth of incorporation) before treated topsoil could be substantially depleted.

The unweathered fly ash used in our study was spread over each individual plot according to given rates, initially rototilled, and left to weather until the spring of 1994. The ash was again rototilled more thoroughly before planting on 1 Apr. 1994. The ash was subjected to natural weathering before planting to allow leaching of soluble salts, including B, from the treated topsoil. Analyses of soil samples taken on 9 Aug. 1993 (i.e., 27 d after application) indicated very high levels of soluble salts, including B, especially at the 560 and 1120 Mg ha^-1 rates (data not shown). By the next sampling on 8 Mar. 1994, EC and B, especially from the 1120 Mg ha^-1 treatment, had not substantially decreased. This explains the rather poor initial plant establishment even after 57 d, as indicated by germination counts, especially at the 1120 Mg ha^-1 rate. However, this initial detrimental effect, including that by the highest rate, was no longer present during the first biomass harvest on 17 Oct. 1994 (Table 4).

Soluble salt concentrations in unweathered ashes are generally high, which may result in EC values exceeding 13 dS m^-1 (Bilski et al., 1995). These kind of EC values exceed levels considered as the threshold for causing adverse effects on most plant species, including agronomic and horticultural crops (Maas, 1990). Salinity problems usually do not occur in plants until the soil EC values are greater than 1.5 for salt-sensitive, 3.5 for moderately salt-sensitive, or 6.5 dS m^-1 for moderately salt-tolerant species (Maas, 1990). In addition to direct effects on plant establishment by phytotoxic constituents in unweathered fly ashes, indirect effects due to inhibited microbial activity by high pH and nutrient imbalances in plants due to the presence of elevated levels of trace elements (e.g., Cd, Cr, Zn, etc.) and soluble salts (e.g., Ca, S) can also occur (Elliot et al., 1982; Arthur et al., 1984; Cervelli et al., 1987; Wong and Wong, 1986; Pitchel and Hayes, 1990). However, these undesirable effects should substantially diminish upon weathering under field conditions (this may take about 1 yr or so depending on the amount of rainfall) (Schutter and Fuhrmann, 1999).

The very high rates of fly ash applied in our study were used because the initial hypothesis was that the tolerant nature of centipedegrass used at the turf farm would preclude any phytotoxicity from excessive soluble salts. Indeed, normal plant establishment was achieved after spreading the fly ash on experimental plots and allowing weathering to induce leaching of salts.

It was apparent from this study that turf farms appear to be a viable utilization venue for fly ashes and other CCPs due to the following observations: (i) plants grown on treated plots were less subject to drought stress than those grown in control plots; (ii) pH of treated soil was within a favorable range for plant growth; (iii) centipedegrass from treated plots grew normally, producing DM yields comparable with controls; (iv) chemical composition of treated plant tissues did not deteriorate (data not shown); and (v) soil levels of potentially toxic trace elements did not prove to be detrimental to plant growth (Adriano and Weber, 1998).

	ACKNOWLEDGMENTS

 
We wish to acknowledge the following individuals: Dr. Phillip Dixon of SREL for his statistical assistance, Ms. Joan Gariboldi and Jason Durdeen of SREL for technical assistance, Dr. David Radcliffe of the University of Georgia for plant-available water measurements and use of water infiltration rate equipment, Mr. Frank Roe of USDA-NRCS for soil coring, and Mr. Jack Mason of Mason's Tree and Turf Farm for use of his farm and field assistance. This study was conducted through a contract between the University of Georgia and EPRI (WO9023-03) and the US-DOE (Contract DE-FC09-96SR18546).

	REFERENCES

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION GENERAL DISCUSSION REFERENCES

 

• Adriano, D.C., A.L. Page, A.A. Elseewi, A.C. Chang, and I. Straughan. 1980. Utilization and disposal of fly ash and other coal residues in terrestrial ecosystems: A review. J. Environ. Qual. 9: 333–344.[Abstract/Free Full Text]
• Adriano, D.C., and J.T. Weber. 1998. Coal ash utilization for soil amendment to enhance water relations and turf growth. EPRI Rep. TR-111318, WO-9023. Electric Power and Res. Inst., Palo Alto, CA.
• American Coal Ash Association. 1998. Annual report. ACAA, Alexandria, VA.
• Arthur, M.A., T.C. Zwick, D.A. Tolle, and P. Van Voris. 1984. Effects of fly ash on microbial CO₂ evolution from an agricultural soil. Water Air Soil Pollut. 22:443–453.
• Bern, J. 1976. Residues from power generation: Processing, recycling, and dispersal. p. 226–248. In Land application of waste materials. Soil Conserv. Soc. Am., Ankeny, IA.
• Bilski, J.J., A.K. Alva, and K.S. Sajwan. 1995. Fly ash. p. 327–363. In J.E. Rechcigl (ed.) Soil amendments and environmental quality. CRC Press, Boca Raton, FL.
• Blake, G.R., and K.H. Hartge. 1986. Particle density. p. 377–382. In A. Klute (ed.) Methods of soil analysis. Part I—Physical and mineralogical methods. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
• Bouwer, H. 1986. Intake rate: Cylinder infiltrometer. In A. Klute (ed.) Methods of soil analysis. Part I—Physical and mineralogical methods. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
• Brady, N.C. 1984. The nature and properties of soils. MacMillan, New York.
• Capp, J.P., and J.D. Spencer. 1970. Fly ash utilization: A summary of applications and technology. p. 13. Bureau Mines Inf. Circ. 8483. U.S. Dep. Interior, Washington, DC.
• Carlson, C.L., and D.C. Adriano. 1993. Environmental impacts of coal combustion residues. J. Environ. Qual. 22:227–247.
• Cassel, D.K., and D.R. Nielsen. 1986. Field capacity and available water capacity. p. 901–926. In A. Klute (ed.) Methods of soil analysis. Part I—Physical and mineralogical methods. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
• Cervelli, S.G., G. Petruzzelli, and A. Pema. 1987. Fly ashes as an amendment in cultivated soils. I. Effect on mineralization and nitrification. Water Air Soil Pollut. 33:331–338.
• Chang, A.C., L.J. Lund, A.L. Page, and J.E. Warnke. 1977. Physical properties of fly ash–amended soils. J. Environ. Qual. 6:267–270.[Abstract/Free Full Text]
• Chang, A.C., A.L. Page, L.J. Lund, J.E. Warneke, and C.O. Nelson. 1989. Municipal sludges and utility ashes and their effects on soils. p. 125–139. In B. Bar Yosef et al. (ed.) Inorganic contaminants in the vadose zone. Ecological studies. Vol. 74. Springer–Verlag, Berlin.
• Clark, R.B., S.K. Zeto, K.D. Ritchey, R.R. Weddell, and V.C. Baligar. 1995. Coal combustion byproduct use on acid soil: Effects on maize growth and soil pH and electrical conductivity. p. 131–155. In Agricultural utilization of urban and industrial by-products. ASA Spec. Publ. 58. ASA, Madison, Wl.
• Elliot, L.F., D. Tittemore, R.T. Papendick, V.L. Cochran, and D.F. Bezdicek. 1982. The effect of Mount Helen's ash on soil microbial respiration and numbers. J. Environ. Qual. 11:164–166.
• El-Mogazi, D., D.J. Lisk, and L.H. Weinstein. 1988. A review of physical, chemical, and biological properties of fly ash and effects on environmental ecosystems. Sci. Total Environ. 74:1–37.[Medline]
• Fail, J.L., Jr., and Z.S. Wochok. 1977. Soybean growth on fly ashamended strip mine spoils. Plant Soil 48:472–484.
• Fisher, G.L., B.A. Prentice, D. Silberman, J.M. Ondov, A.H. Bierman, R.C. Ragaini, and A.R. McFarland. 1978. Physical and morphological studies of size-classified coal fly ashes. Environ. Sci. Technol. 12: 447–451.
• Furr, A.K., T.F. Parkinson, R.A. Hinrichs, D.R. Van Campen, C.A. Bache, W.H. Gutenmann, L.E. St. John, Jr., I.S. Pakkala, and D.J. Lisk. 1977. National survey of elements and radioactivity in fly ashes: Absorption of elements by cabbage grown in fly ashsoil mixtures. Environ. Sci. Technol. 11:1194–1201.
• Gardner, W.H. 1986. Water content. p. 493–544. In A. Klute (ed.) Methods of soil analysis. Part I—Physical and mineralogical methods. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.
• Jacobs, L.W., A.E. Erickson, W.R. Berti, and B.M. MacKellar. 1991. Improving crop yield potentials of coarse textured soils with fly ash amendments. In Proc. 9th Int. Ash Use Symp. Vol. 3. EPRI GS-7162. Am. Coal Ash Assoc., Alexandria, VA.
• Maas, E.V. 1990. Crop salt tolerance. p. 262–304. In K.K. Tanji (ed.) Agricultural salinity assessment and management. Manual on Engineering Practice no. 71. Am. Soc. Chem. Eng., New York.
• Mattigod, S.V., D. Rai, L.E. Eary, and C.C. Ainsworth. 1990. Geochemical factors controlling the modilization of inorganic constituents from fossil fuel residues: I. Review of the major elements. J. Environ. Qual. 19:188–201.[Abstract/Free Full Text]
• Nass, M.M., T.M. Lexmond, M.L. van Beusichem, and M. Janssen-Jurkovicova. 1993. Long-term supply and uptake by plants of elements from coal flyash. Commun. Soil Sci. Plant Anal. 24:899–913.
• Natusch, D.F.S., C.F. Bauer, H. Matusiewicz, C.A. Evans, J. Baker, A. Loth, R.W. Linton, and P.K. Hopke. 1975. Characterization of trace elements in fly ash. p. 553–575. In T.E. Hutchinson (ed.) Proc. Int. Conf. on Heavy Metals in the Environ., Toronto, ON, Canada. 27–31 Oct. 1975. Vol. 2, Part 2. Univ. of Toronto.
• Page, A.L., A.A. Elseewi, and I. Straughan. 1979. Physical and chemical properties of fly ash from coal-fired power plants with reference to environmental impacts. Residue Rev. 71:83–120.
• Phung, H.T., L.J. Lund, and A.L. Page. 1978. Potential use of ash as a liming material. p. 504–515. In D.C. Adriano and I.L. Brisbin (ed.) Enviromental chemistry and cycling processes. CONF760429. U.S. Dep. of Commerce, Springfield, VA.
• Pitchel, J.R., and J.M. Hayes. 1990. Influence of fly ash on soil microbial activity and populations. J. Environ. Qual. 19:593–597.[Abstract/Free Full Text]
• Plank, C.O., and D.C. Martens. 1974. Boron availability as influenced by application of fly ash to soil. Soil Sci. Soc. Am. Proc. 38:974–977.
• Salter, P.J., G. Berry, and J.B. Williams. 1966. The influence of texture on moisture characteristics of soils. III. Quantitative relationship between particle size composition and available water capacity. J. Soil Sci. 17:93–97.
• SAS Institute. 1990. SAS/STAT user's guide. Version 6, 4th ed., Volume 2. SAS Inst., Cary, NC.
• Schutter, M.E., and J.J. Fuhrmann. 1999. Microbial responses to coal fly ash under field conditions. J. Environ. Qual. 28:648–652.[Abstract/Free Full Text]
• Schwab, A.P., M.B. Tomecek, and P.D. Ohlenbusch. 1991. Plant availability of lead, cadmium, and boron in amended coal ash. Water Air Soil Pollut. 57/58:297–306.
• Sikka, R., and B.D. Kansal. 1995. Effect of fly ash application on yield and nutrient composition of rice, wheat and on pH and available nutrient status of soils. Bioresour. Technol. 51:199–203.
• Straughan, I., A.A. Elseewi, and A.L. Page. 1978. Mobilization of selected trace elements in residues from coal combustion with special reference to fly ash. Trace Subst. Environ. Microbiol. 45: 743–747.
• USDA. 1997. An economic assessment of turfgrass sod. Executive summary report [Online]. Available at http://www.act.fcic.usda.gov/research/turfsod.tx.
• USEPA. 1988. Wastes from the combustion of coal by electric utility power plants. USEPA Rep. 530SW88002. U.S. Gov. Print. Office, Washington, DC.
• Wong, M.H., and J.W.C. Wong. 1986. Effects of fly ash on soil microbial activity. Environ. Pollut. Ser. A 40:127–144.

This article has been cited by other articles:

				C. Barton, D. Marx, D. Adriano, B. J. Koo, L. Newman, S. Czapka, and J. Blake Phytostabilization of a landfill containing coal combustion waste Environmental Geosciences, December 1, 2005; 12(4): 251 - 265. [Abstract] [Full Text] [PDF]

				M. J. Schlossberg, C. P. Vanags, and W. P. Miller Bermudagrass Sod Growth and Metal Uptake in Coal Combustion By-Product-Amended Media J. Environ. Qual., March 1, 2004; 33(2): 740 - 748. [Abstract] [Full Text] [PDF]

				S. M. Pathan, L. A. G. Aylmore, and T. D. Colmer Properties of Several Fly Ash Materials in Relation to Use as Soil Amendments J. Environ. Qual., March 1, 2003; 32(2): 687 - 693. [Abstract] [Full Text] [PDF]

This Article Abstract Figures Only Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (28) Citing Articles via Google Scholar Google Scholar Articles by Adriano, D. C. Articles by Weber, J. T. Search for Related Content PubMed PubMed Citation Articles by Adriano, D. C. Articles by Weber, J. T. GeoRef GeoRef Citation Agricola Articles by Adriano, D. C. Articles by Weber, J. T. Related Collections Industrial Waste Soil Chemistry