Progress 10/01/02 to 09/30/03
Outputs
Biosolids recycling has increased significantly during the past ten years. The benefit of land applying biosolids is its ability to effectively enhance agricultural crop production by increasing the amount of organic matter and nutrients to the soil. Due to this enhanced production, municipal wastewater treatment plants now commonly use environmental biosolids management systems. The presence of contaminants such as heavy metals in small, bioavailable quantities give reason for concern and may pose a health threat due to accumulation in the food chain. The general public continues to question the safety of land applying biosolids due to these concerns. In the present study, a matrix of biosolids, biosolid-treated soils, and untreated soils from 7 sites from different geographic locations throughout the US were collected and analyzed. Chemical extractants (0.05 M CaNO3, 1.0 M NH4Oac, 0.005 M DTPA, and PBET) were selected to evaluate the concentrations of metals they
extract to determine which are the most sensitive to changes in metal loading in soils with a range of chemical physical properties. Five of the sites are managed by municipalities and follow Part 503 guidelines (US EPA 1993). The remaining two sites received high applications of contaminated sewage sludge prior to Part 503 rules. Extraction metal concentrations were also compared to measured biotoxicity to see if a correlation between metals from biosolid amendments and toxicity could be established.
Impacts
The chemical extractants evaluated in this study will be used to help evaluate the potential or residual toxicity of soils amended with biosolids. Several of the extractants, particularly the calcium nitrate and DTPA, had high correlation with total metal loads. The PBET test has been shown by others to be an excellent means of predicting uptake of Pb and As by mammals after ingestion of contaminated soils. Therefore, these tests and the data generated in this project have the potential to be used in a broad array of applications.
Publications
- No publications reported this period
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Progress 10/01/99 to 09/30/02
Outputs
The Clean Water Act requires that municipalities treat wastewater to allow safe return of this resource to the environment. Wastewater treatment generally produces biosolids, a byproduct that has a high water content and is nutrient-rich. Biosolids can be recycled and applied to crop land to improve soil quality and productivity because of the nutrients and organic matter that they contain. Once called sewage sludge, the term biosolids is now the preferred to emphasize that this recyclable material can have a beneficial use. In addition to a high water content, biosolids are often solids and dissolved substances that were present in the wastewater or were added during treatment processes. The annual generation of municipal biosolids in the United States has dramatically increased from approximately 4.6 million dry tons in 1972 (Bastian, 1997) to 6.9 million dry tons in 1998. Wastewater treatment plants treat both wastewater and the resulting biosolids, often using
different technologies designed specifically for each treatment process. The regulatory requirements found in The Standards for the Use or Disposal of Sewage Sludge (Title 40 of the Code of Federal Regulations [CFR], Part 503), which was published in the Federal Register in 1993, established the regulations limiting the pollutants and pathogens in biosolids. Municipal biosolids may be applied to agricultural land if the biosolids conform to CFR Part 503 and if land applications do not exceed guidelines of annual nitrogen applications and total accumulations of heavy metals. Despite the extensive efforts and experience that were essential to the establishment of Part 503 regulations, concerns still exist that the biosolid applications are not protective enough. In response to these concerns, a series of protocols were developed to screen soils amended with biosolids for potential metal toxicity. A guidance document has been prepared that details the procedures to be used for sampling
soils, preparing samples, conducting the toxicity protocols, and interpreting the results.
Impacts
The chemical extractants evaluated in this study will be used to help evaluate the potential or residual toxicity of soils amended with biosolids. Several of the extractants, particularly the calcium nitrate and DTPA, had high correlation with total metal loads. The PBET test has been shown by others to be an excellent means of predicting uptake of Pb and As by mammals after ingestion of contaminated soils. Therefore, these tests and the data generated in this project have the potential to be used in a broad array of applications.
Publications
- Parrish, Z.D., M.K. Banks, and A.P. Schwab. 2004. Effectiveness of phytoremediation as a secondary treatment for polycyclic aromatic hydrocarbons (PAHs) in composted soil. Phytoremediation 6:119-137.
- Parrish, Z.D., M.K. Banks, and A.P. Schwab. 2004. Effect of Root Death and Decay on Dissipation of Polycyclic Hydrocarbons in the Rhizosphere of Melilotus officinalis and Festuca arundinacea. J. Environ. Qual.
- Sonon, L. and A.P. Schwab. 2004. Transport and persistence of nitrate, atrazine, and alachlor in large, intact soil columns under two levels of water saturation. Soil Sci. 169:541-553
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Progress 10/01/01 to 09/30/02
Outputs
Despite the passage and enforcement of U.S. EPA 503 regulations, concern still exists about potential long-term contamination and health effects of metals in biosolids applied to soil. This project was initiated to investigate the potential impacts and toxicity associated with applying biosolids (sewage sludge) to soils. Five municipalities were identified from across the U.S. to participate in this project. They were chosen to give a broad sampling of geographic location and soil types. Our research team visited each city, and we sampled the biosolids, soil amended with biosolids that year, soil amended with biosolids for 5 or more years, and clean soil. All facilities were following the guidelines of the 503 regulations. In addition, we sampled a soil from a large city that had received non-compliant (high metal) biosolids for 20 years, and a soil that had received 20 tons/acre of high metal sludge 25 years ago. Bioavailability and chemical lability of metals were
evaluated using earthworm tests (mortality, weight gain, and reproduction), lettuce germination, microbial respiration, nematode toxicity, and extractability with a series of chemical solutions. In all cases, the application of sludge did not impact significantly any of the bioindicators relative to the clean, control soils. Extractability of the metals likewise was unaffected by a single year's application of biosolids. However, five years or more of biosolid application resulted in approximately 5 to 10% more extractable metals than in the absence of application. The high-metal sludges had slightly elevated metal concentrations. Our conclusion from this study is that metal toxicity is not an issue for field application of these biosolids because nitrogen and phosphorus are limiting the quantity of material that may be applied. Only in cases in which N and P are low will metals limit the rate of application, and higher levels of potentially toxic metals may be possible. Even under
those circumstances, it seems unlikely that the metals will reach toxic levels.
Impacts
The applicability of this research may be found in our conclusion that the U.S. EPA 503 regulations were adequate to protect soils from contamination and to minimize negative health impacts. Thus, despite the ongoing concern about whether or not the regulations are conservative enough, following the guidelines over the short-term (one to five years) will protect the environment.
Publications
- No publications reported this period
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Progress 10/01/00 to 09/30/01
Outputs
The overall objective of this research is to develop an integrated series of bioassays to evaluate the potential toxicity of biosolids and/or biosolid/soil matrices. Individual bioassay tests have been modified from accepted protocols and evaluated in the laboratory for ease of use, relative costs, and sensitivity. The bioassays consist of microbial, earthworm, and seedling assessments. In addition, we are developing chemical extractants to provide semi-quantitative data on bioavailability and potential toxicity of specific chemicals. Twenty land application sites were evaluated for field validation. These sites were chosen at different geographic locations throughout the U.S. Each site uses biosolids generated from municipal anaerobic sludge treatment with polymer dewatering. Toxicity assessment data on a representative matrix of biosolids and soils are being conducted. The toxicity tests selected include earthworm growth/reproduction; seedling emergence and
contaminant uptake; nematode vigor and reproduction; nitrification; and microbial respiration. A preliminary screening was performed on sewage sludge from 20 municipalities in California, Oregon, Missouri, Texas, Illinois, Ohio, Iowa, Nebraska, Wisconsin, North Carolina, Colorado, and Indiana. Respiration was not influenced by biosolids. Lettuce emergence for biosolid treated soil was statistically equivalent to untreated, control soils for all but one site. Nitrifier activities were reduced on two treated soils. In contrast, earthworm biomass was significantly lower after incubation in treated soil compared to controls. Earthworm mortality was observed in one soil. Negative treatment impacts did not overlap for any of the tests. In the next phase of the research, we will be selecting 5 sites for more detailed study. The sites will maintain geographical diversity and will be chosen to represent a range in toxicities. If toxicity to any biological indicators is observed, we will
attempt to determine the cause of the toxicity. Also, the chemical extraction tests will be brought into focus.
Impacts
The impact of applying biosolids (sewage sludge, manure, and other wastes) to soils is being investigated with respect to toxicity to soil-borne organisms. We have tested sewage sludge from 20 cities and found that even fresh applications have limited effects. Earthworms are proving to be the most sensitive indicators.
Publications
- Hutchinson, S.L., A.P. Schwab, and M.K. Banks. 2001. Phytoremediation of aged petroleum sludge: effect of irrigation techniques and scheduling. J. Environ. Qual. 30:1516-1522.
- Hutchinson, S.L., M.K. Banks, and A.P. Schwab. 2001. Phytoremediation of petroleum sludge: impact of inorganic fertilizer. J. Environ. Qual. 30:395-403.
- Siciliano, S. D., Fortin, N., Mihoc, A., Wisse, G., Labelle, S., Beaumier, D., Ouellette, R. R., Whyte, L. G., Banks, M. K., Schwab, P., Lee, K., and C. W. Greer. 2001. Selection of specific endophytic bacterial genotypes by plants in response to soil contamination. Applied Environmental Microbiology. 67:2469-2475.
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Progress 10/01/99 to 09/30/00
Outputs
Land application of biosolids has proven to be beneficial because organic matter and nutrients can be used effectively for enhancement of agricultural crop production. There is concern, however, about the potential for degradation of soil quality. A research project was established this year to investigate the impact of biosolids application on potential soil toxicity. The overall objective of this research is to develop an integrated series of bioassays to evaluate the potential toxicity of biosolids and/or a biosolid/soil matrices. To meet this objective, we have established the following subobjectives: 1) Individual bioassay tests will be selected from modifications of accepted protocols and evaluated in the laboratory for ease of use, relative costs, and sensitivity. The bioassays will consist of microbial, earthworm, and seedling assessments. In addition, we will use a chemical extractant or extractants to provide semi-quantitative data on bioavailability and
potential toxicity of specific chemicals. 2) After each protocol has been developed, a number of land application sites will be evaluated for field validation. These sites will be chosen at different geographic locations throughout the US. We will focus on sites using biosolids generated from municipal anaerobic sludge treatment with polymer dewatering. 3) Toxicity assessment data on a representative matrix of biosolids and soils will be provided to WERF and all interested parties. In addition, step-by-step procedures for each protocol will be provided in detail. We will select protocols using organisms that have reasonable sensitivity to soil contaminants, a proven track record, and provide representative toxicity data. This will be approached in two phases as shown in Figure 3. In Phase I, we will execute a laboratory-based study to develop an integrated biotoxicity procedure that is composed of a series of bioassays. The toxicity evaluations will be selected or modified from
existing procedures and applied to biosolids. A chemical extractant or extractants will be selected or developed to provide semi-quantitative data on potential toxicity of specific chemicals. We will be cooperating with approximately 20 WERF utility subscribers who will provide biosolids samples. We plan to work with WERF staff and our advisory team to identify likely candidates. Based on the initial toxicity screening, 5 cities will be chosen for further participation in the project. Phase II of this research is a field validation study. A matrix of biosolids, biosolid-treated soils, and untreated soils from the 5 sites will be collected and analyzed for biotoxicity and target contamination.
Impacts
Although the applied of biosolids to soils is regulated and closely monitored, controversy and concern exists concerning the loading of heavy metals onto agricultural soils. The data generated in this project will address some of the specific issues in this debate, particularly the release of metals from the organic matrix upon weathering. This may provide further insight into whether or not the current regulations are adequate or need further refinement.
Publications
- No publications reported this period
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Progress 10/01/98 to 09/30/99
Outputs
In 1976, municipal sewage sludge was applied at various rates to a large set of plots at the Agronomy Farm in West Lafayette, Indiana. The sludge had fairly high concentrations of heavy metals (concentrations in mg/kg): 284 Cd, 2040 Ni, 6800 Zn, 1200 Cu, and 1070 Pb. The sludge was applied at rates up to 448 metric tons per hectare. The plots were permanently marked and cropped in wheat, oats, soybean, and corn for the past 22 years. We have intensively sampled the soils from these plots and have begun the process of quantifying the distribution of metals with depth. A chemical fractionation scheme will be used that will yield total concentrations as well as water soluble, exchangeable, and more recalcitrant fractions. An index of availability will be determined by the DTPA extraction procedure. The soils also will be thoroughly characterized for chemical and physical properties to determine any residual impact of the sludge applications. In addition, we will be
measuring plant uptake (leaves and grain) of heavy metals for several growing seasons and with different crops. This measure of plant availability will be correlated with the metal concentrations determined in the procedure given above to determine a) residual bioavailability of the metals in the sludge after two decades of cropping, and b) the ability of the soil-chemical extraction procedures to predict plant uptake.
Impacts
Although the applied of biosolids to soils is regulated and closely monitored, controversy and concern exists concerning the loading of heavy metals onto agricultural soils. The data generated in this project will address some of the specific issues in this debate, particularly the release of metals from the organic matrix upon weathering. This may provide further insight into whether or not the current regulations are adequate or need further refinement.
Publications
- No publications reported this period
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Progress 10/01/97 to 09/30/98
Outputs
Efforts to minimize wastes and be effective stewards of soil and water resources has resulted in application of animal manure as a nutrient sorce and an increased use of treated effluents for irrigation. These practices, though resource conservative, may have a number of shortcomings. The use of treated effluents for irrigation has been postulated to facilitate movement of soil-borne pesticides. Factors that may result in enhanced downward movement of pesticides include complexation with dissolved organic material (DOM) present in effluent, coating of soil surfaces with effluent DOM, effluent-induced increases in soil-solution pH, effluent-induced decreases in pore-water velocity, and effluent-induced changes in microbial ecology. The potential of municipal wastewater effluent and swine-derived lagoon effluent to enhance the mobility of prometryn, atrazine, chlorpyrifos, and metabolites was evaluated using batch, column, and modeling techniques. For chlorpyrifos,
soprtion was reduced and apparent retardation factors decreased in the presence of animal-derived effluents as a function of the amount and polarity of DOM present. Although transport may be enhanced by effluent irrigaiton, mobility of chlorpyrifos is still considerably limited. Effluent-induced increases in soil-solution pH did enhance movement of chlorpyrifos metabolites (3,5,6-trichloro-2-pyridinol)in acidic soils due to the pH-induced shift towards the more mobile organic anion. Given the moderate polarity of triazines, facilitated transport of pesticide is most likely not due to complexation with effluent DOM. However, effluent-induced increases in soil-solution pH and decreases in pore-water velocity indicated that there was some potential for enhanced transport under treated-effluent irrigation. Coupled impact of decreased pore-water velocity with wetting and drying event on enhanced pesticide mobility was dependent of soil texture, drying period, and climate conditions.
Potential P based land application limits for animal manure mandate the development of simple, rapid, and reliable laboratory techniques for estimating potential edge of field losses of soluble and bioavailable P. We evaluated relationships among soil test P methods for soils with elevated P levels due to previous manure applications, and related these values to i) soluble P concentration (SPC) and bioavailable P (BAP). Of the soil test P methods evaluated, Bray P1 was most highly correlated to SPC and BAP. SPC was approximately 0.1, 0.25, 0.5, 1.0 and 2.0 mg P/L when Bray P1 exceeded 50, 75, 150, 200 and 500 mg P/kg, respectively. Amorphous Fe contents directly influence the relationship between BAP and Bray P1. We have adapted the SPC procedure for routine soil test purposes because it also is well related to BAP.
Impacts
(N/A)
Publications
- Baxter, C.A., B.C. Joern, and O. Adeola. 1998. Dietary P management to reduce soil P loading from pig manure. In D. Franzen (ed.) Proceedings of the Twenty-eighth north central extension-industry soil fertility conference.
- Brokish, J.A. 1998. Threshold phosphorus levels for Indiana Soils. M.S. thesis. Purdue University, West Lafayette, IN.
- Moore, P.A., B.C. Joern and T.L. Provin. 1998. Improvements needed in environmental soil testing for phosphorus. pp. 21-30. In J.T. Sims (ed.) Soil Testing For Phosphorus: Environmental Uses and Implications. Southern Coop. Series Bull. No. 389. (A publication of SERA-IEG 17 USDA-CSREES Regional Committee: Minimizing Agricultural Phosphorus Losses for Protection of the Water Resource).
- Sims, J.T., R.R. Simard, and B.C. Joern,. 1998. Phosphorus losses in agricultural drainage: historical perspective and current research. J. Environ. Qual. 27:277-293.
- Baxter, C.A., B.C. Joern, O. Adeola, and P.A. Moore. 1998. Phosphorus excretion by pigs as influenced by high available phosphorus corn and phytase. Agron. Abstr. P. 349.
- Brokish, J.A., and B.C. Joern. 1998. Soluble and bioavailable phosphorus in soils: a methods comparison. Agron. Abstr. P. 348.
- Seol, Y. 1998. An Inquiry into the phenomenon of enhanced transport of triazines with treated effluents. Ph.D. Thesis. Purdue University, West Lafayette, IN.
- Huang, X. 1998. Impact of animal waste lagoon effluents on the fate of chlorpyrifos and metabolites in soils. Ph.D. Thesis. Purdue University, West Lafayette, IN.
- Brokish, J.A., B.C. Joern, and T.L. Provin. 1997. Using soil properties to predict soluble phosphorus losses from Indiana soils. Agron. Abstr. P. 329.
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Progress 10/01/96 to 09/30/97
Outputs
Recent trends in agribusiness have led to large concentrations of animal production facilities which produce huge quantities of animal manure. As a biological treatment process, the use of lagoons to degrade organic matter derived from feed, bedding, and body byproducts is most common in the Midwest. Lagoon supernatants from livestock facilities are then typically applied on nearby land by sprinkler or surface irrigation. Although the minimization of odor, surface runoff, and the accumulation of undesirable levels of nutrients and toxic materials in the soils and plants have been of concern, no attention has been given to the effect that these amendments may have on pesticide degradation/transport and subsequent risks to groundwater quality. Our research is directed towards identifying the effects of lagoon effluents on pesticide degradation and transport. Our work has primarily been with chlorpyrifos because of its common use to kill a wide variety of insects, the
use of lagoon effluents for irrigation at a Purdue University Research Farm where chlorpyrifos is extensively applied, and the fact that the major metabolite 3,5,6-trichloro-2-pyridinol (TCP) has both toxicity and efficacy similar to the parent compound. Our approach includes incubation experiments with effluent and effluent-moist soil, and column leaching studies where several parameters are measured including chlorpyrifos, metabolite, dissolved organic matter concentrations, pH, and electric conductivity. Chlorpyrifos degradation was significantly enhanced when incubated with lagoon effluents. In the presence of soil, lagoon effluents had much less impact on the rate of chlorpyrifos degradation. However, large differences in the rate of degradation were observed between soils with degradation being much greater on the higher pH soil. The transport of TCP was facilitated under animal effluent irrigation as a result of the pH-induced shift in the speciation of TCP. The potential
practical applications of these research results include the potential to optimize irrigation schemes as a function of soil and pesticide type; and the potential to use animal lagoon effluent as a source of microbes and nutrients for enhancing bioremediation.
Impacts
(N/A)
Publications
- Huang, X. and L.S. Lee. 1996. Enhanced transport of chlorpyrifos by effluents from animal waste lagoons, Amer. Soc. Agronomy, CA (October 26-30, 1997), p. 325.
- Huang, X. and L.S. Lee. 1997. Fate of chlorpyrifos and metabolites in fields irrigated with animal waste lagoon effluent. 20th Midwest Environmental Chemistry Workshop, Indiana University, Bloomington, IN, (November 8-9, 1997).
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Progress 10/01/95 to 09/30/96
Outputs
The movement of the livestock industry toward centralized confinement facilitieshas caused significant increases in extractable soil phosphorus (P) in the area surrounding these facilities. Excessively high levels of extractable P increases the potential for contamination of surface waters. Eleven surface soils and their respective subsurface horizons (42 total horizons) were incubated in the laboratory with 25, 50, 100, and 200 mg P kg-1 soil for one year. Following incubation, soils were analyzed for Bray P1, resin-exchangeable P, and water soluble P. Results from the Bray P1 soil test was the single factor most highly correlated to water-soluble phosphorus (r-0.864). Correlations between P solution concentrations and Bray P1 test levels improved (r=0.947) with inclusion of exchangeable Ca. The use of such correlations will improve our ability to predict the potential for phosphorus contamination from surface runoff and tile drainage from animal manure fields.
Impacts
(N/A)
Publications
- Moore, P.A., B.C. Joern, and T.L. Provin. 1997. Environmental soil test methods for phosphorus. In: J.T. Sims (ed.) Soil testing for phosphorus: Environmental uses and implications. Southern Regional Special Bulletin (In press).
- Provin, T.L. 1996. Phosphorus retention in Indiana soils. Ph.D. Dissertation, Purdue University, West Lafayette, IN.
- Sims, J.T., and R.R. Simard. 1996. Phosphorus losses in agricultural drainage: Historical perspective and current research. Amer. Soc. Agronomy, Indianapolis, IN, (November 3-8, 1996), p. 294.
- Sims, J.T., and R.R. Simard. 1997. Phosphorus losses in agricultural drainage: Historical perspective and current research. J. Environ. Quality. 26:(in press).
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Progress 10/01/94 to 09/30/95
Outputs
The movement of the livestock industry toward centralized confinement facilitieshas caused significant increases in extractable soil phosphorus (P) in the area surrounding these facilities. Excessively high levels of extractable P increases the potential for contamination of surface waters. Eleven surface soils and their respective subsurface horizons (42 total horizons) were incubated in the laboratory with 25, 50, 100, and 200 mg P kg-1 soil for one year. Following incubation, soils were analyzed for Bray P1, resin-exchangeable P, and water soluble P. Solution P levels exceeded 0.1 mg P L-1 (reported critical value for algae blooms) when Bray P1 soil test levels exceeded approximately 50 mg P kg-1 (r2=0.68). Correlations between P solution concentrations and Bray P1 test levels improved (r2=0.88) with inclusion of exchangeable Ca and Mg, organic carbon, and oxalate-extractable P, Al, and Fe. The use of such correlations will improve our ability to predict the
potential for phosphorus contamination from surface runoff and tile drainage from animal manure fields.
Impacts
(N/A)
Publications
- Provin, T.L., R.R. Banda, and B.C. Joern. 1995. Extractable-phosphorous, Water-soluble Phosphorus, and Phosphorous Leaching in Incubated and Field Soils. Agron. Abst., p 346.
- Provin, T.L., B.C. Joern, D.P. Franzmeier, and A.L. Sutton. 1995. Phosphorus retention in selected Indiana soils using short-term sorption isotherms and long-term aerobic incubations. pp. 35-42. In: Impact of Animal Waste on the Land-Water
- Provin, T.L. and B.C. Joern, 1995. Soil Application of Aluminum Industry By-product: Influences on Soil Chemistry and Plant Nutrition. Abst., 50th Industrial Waste Conf., Purdue Univ., May 8-10, 1995, p. 43-44.
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Progress 10/01/93 to 09/30/94
Outputs
Minimizing inadvertent additions of phosphorus to surface and groundwater by non-point agricultural sources requires a fundamental understanding of phosphorus dynamics in soils. The physical and chemical properties controlling phosphorus (P) sorption by Indiana soils are being assessed. Phosphorus sorption isotherms have been performed on several surface soils and their respective subsurface horizons. Individual soil horizons were incubated for one year with phosphorus additions between 0 and 200 mg P kg(superscript -1). Initial and final Bray P(subscript 1) and water soluble P levels showed tremendous differences in P retention between soil series and within soil horizons for a given soil. Results are being evaluated as a function of pH, particle size analysis, total surface area, total P, exchangeable bases, and clay mineralogical properties.
Impacts
(N/A)
Publications
- PROVIN, T.L. and JOERN, B.C. 1993. Phosphorus sorption capacities of selected Indiana soils. Abstract, Amer. Soc. Agronomy, Madison, WI, p 234.
- PROVIN, T.L. and JOERN, B.C. 1994. Soil chemical and physical properties controlling solution phosphorus in Indiana soils. Abstract, Amer. Soc. Agronomy, Seattle, WA, (Nov. 13-18, 1994).
- RAO, P.S.C., LEE, L.S., AUGUSTIJN, D.C.M., and WOOD, A.L. 1994. Environmental fate and transport of organic contaminants in soils at waste disposal sites. Environmental Soil Science Conference Proceedings, Canadian Soil Science Society Ann.
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