Journal of Environmental Quality 32:909-915 (2003)
© 2003 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America
TECHNICAL REPORTS
Heavy Metals in the Environment
Surface Runoff Losses of Copper and Zinc in Sandy Soils
Mingkui Zhanga,
Zhenli He*,a,b,
David V. Calvertb,
Peter J. Stoffellab and
Xiaoe Yanga
a Dep. of Natural Resource Sciences, College of Natural Resource and Environmental Sciences, Zhejiang Univ., Huajiachi Campus, Hangzhou 310029, China
b Univ. of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945-3138
* Corresponding author (zhe{at}mail.ifas.ufl.edu)
Received for publication July 18, 2002.
 |
ABSTRACT
|
|---|
Increased anthropogenic inputs of Cu and Zn in soils have caused considerable concern relative to their effect on water contamination. Copper and Zn contents in surface soil directly influence the movement of Cu and Zn. However, minimal information is available on runoff losses of Cu and Zn in agricultural soils, and soil-extractable Cu and Zn in relation to runoff water quality. Field experiments were conducted in 2001 to study dissolved Cu and Zn losses in runoff in Florida sandy soils under commercial citrus and vegetable production and the relationship between soil-extractable Cu and Zn forms and dissolved Cu and Zn concentrations in runoff water. Five extraction methods were compared for extracting soil available Cu and Zn. Concentrations of dissolved Cu and Zn in runoff were measured and runoff discharge was monitored. Mean dissolved Cu in field runoff water was significantly correlated with the extractable Cu obtained only by 0.01 mol L-1 CaCl2, Mehlich 1, or DTPA–TEA methods. Dissolved Zn in runoff water was only significantly correlated with extractable Zn by 0.01 mol L-1 CaCl2. The highest correlations to dissolved Cu in runoff were obtained when soil-available Cu was extracted by 0.01 mol L-1 CaCl2. The results indicate that 0.01 mol L-1 CaCl2–extractable Cu and Zn are the best soil indexes for predicting readily released Cu and Zn in the sandy soils. Both runoff discharge and 0.01 mol L-1 CaCl2–extractable Cu and Zn levels had significant influences on Cu and Zn loads in surface runoff.
Abbreviations: DTPA, diethylenetriaminepentaacetic acid • TEA, triethyl amine
|
INTRODUCTION
|
|---|
IN RECENT YEARS, INCREASED ANTHROPOGENIC inputs of heavy metals in soils have caused considerable concern relative to their effect on water contamination (Purves, 1985; Alloway, 1995; Moore et al., 1998). Although heavy metals are generally considered to be relatively immobile in most soils, their mobility in certain contaminated soils may exceed ordinary rates and pose a significant threat to water quality (Scokart et al., 1983; Jorgensen, 1991; Alva, 1992; Maskall et al., 1995; Bunzl et al., 2001). Organic manure, municipal waste, and some fungicides often contain fairly high concentrations of heavy metals. Soils receiving repeated applications of organic manures, fungicides, and pesticides have exhibited high concentrations of extractable heavy metals (Payne et al., 1988; Kingery et al., 1994; Sims and Wolf, 1994; van der Watt et al., 1994; Li et al., 1997; Moore et al., 1998; Han et al., 2000) and increases in heavy metal concentrations in runoff (Moore et al., 1998). Copper and Zn are consistently added to soils in the form of fertilizers, pesticides, livestock manures, sewage sludge, and industrial emissions (Adriano, 1989). Both of these metals have moderate mobility under slightly acid soil conditions (Elliott et al., 1986; Jorgensen, 1991; Hesterberg et al., 1993). Copper and Zn concentrations in the runoff water from a field were as high as 0.7 and 0.1 mg L-1 following long-term application of poultry litter (Edwards et al., 1997). These studies indicate a potential for nonpoint-source metal pollution from fields and the possibility of Cu and Zn transport from soil to water. Copper and Zn accumulate in soils in water-soluble, exchangeable, carbonate-associated, oxide-associated, organic-associated, and residual forms. Copper and Zn present in these categories have different mobility (Iyengar et al., 1981; Sims and Kline, 1991; Moore et al., 1998). Water-soluble and exchangeable fractions would be readily released to the environment, whereas the residual fraction is immobile under natural conditions. Previous studies indicate that metal contents of surface soil directly influence the movement of metals, especially in sandy soils (Scokart et al., 1983; Edwards et al., 1997; Moore et al., 1998; Cezary and Singh, 2001). The concentrations of heavy metals in runoff were related to status of heavy metals in soil near urban highways (Turer et al., 2001). Unfortunately, minimal information is available on runoff losses of dissolved Cu and Zn in agricultural soils. The relationship between overland flow and metal transfer is not well documented. The objectives of this study were to investigate Cu and Zn surface runoff losses in Florida sandy agricultural soils and explore the relationship between extractable Cu and Zn forms and dissolved Cu and Zn concentrations in field runoff water.
|
MATERIALS AND METHODS
|
|---|
Eleven field sites (seven at commercial citrus groves and four at vegetable production farms) in St. Lucie and Martin Counties, Florida were selected to monitor Cu and Zn losses in surface runoff in 2001 (Table 1). Portable autosamplers (SIGMA 900MAX; American Sigma, Loveland, CO1) were installed at the drainage outlet for each site. Rainfall and runoff flow rate were recorded every 10 min. All sites were distributed in the Indian River area of Florida with flat landscape (<5% slope) and shallow water table (30–80 cm) where the dominant hydrological pathways were an extensive network of artificial drainage ditches. The soils of the experiment sites were representative for commercial citrus and vegetable production systems in the Indian River area. They included Wabasso sand (sandy, siliceous, hyperthermic Alfic Alaquod), Waveland fine sand (sandy, siliceous, hyperthermic, ortstein Arenic Alaquod), Ankona sand (sandy, siliceous, hyperthermic, ortstein Arenic Ultic Alaquod), Winder variant sand (fine-loamy, siliceous, superactive, hyperthermic Typic Glossaqualf), and Nettles sand (sandy, siliceous, hyperthermic, ortstein Alfic Arenic Alaquod). General characteristics of the study sites are given in Table 1. In addition to application of N, P, and K, it has been common for the citrus and vegetable producers in the areas to routinely apply micronutrient fertilizers (annual foliar application of Cu and Zn ranged from 2.2 to 5.6 kg ha-1 as copper sulfate, 2.2 to 4.5 kg ha-1 as zinc sulfate, or 0.8 to 1.1 kg ha-1 as chelated zinc), Cu- and Zn-containing pesticides, and fungicides (such as copper hydroxide) that accelerate Cu and Zn accumulation in the soils (Simonne and Hochmuth, 2001). Total rainfall during the experiment (1 Jan. 2001–30 Dec. 2001) for the 11 sites ranged from 1203 to 1572 mm. Rainfall varied seasonally, and most of the rainfall occurred from May to October (Fig. 1)
.
Runoff samples from each field of the sites were collected in 1-L bottles placed inside each autosampler during each rainfall event. The autosamplers were programmed so that six individual surface runoff samples were taken per 24 h. The first three samples were collected in the first 2 h after the sampling process was trigged, each for 40 min in sequence. During the first 40 min the sampler collected three subsamples (one subsample every 13 min and 20 s) that were combined as Sample 1. The remaining three combined samples were collected into another three bottles, each for 7 h and 20 min in sequence. The autosamplers were checked daily to ensure proper performance and to collect surface runoff samples, if available. Data of rainfall and flow recorded in the autosamplers were transferred weekly into a laboratory computer with a data logger. Water samples collected from the autosamplers were immediately transported to the laboratory. A portion of the samples was filtered through Whatman (Maidstone, UK) #42 filter paper. Concentrations of total dissolved Cu and Zn in water were determined with inductively coupled plasma–atomic emission spectrometry (ICP–AES) (Ultima; Jobin Yvon Horiba, Edison, NJ). The number of runoff water samples obtained from each field site varied from 6 to 113 due to differences in rainfall, soil infiltration condition, field slope, and land use among the different sites.
For each site, two composite soil samples were taken across each experimental field in July 2001. Each composite sample was composed of a mixture of four samples taken at a depth of 0 to 150 mm from four locations within each field. All soil samples were air-dried and ground to <2 mm before chemical analysis. Soil pH and electrical conductivity (EC) were measured in water at a soil to water ratio of 1:1 with a pH–ion conductivity meter (Accumet Model 50; Fisher Scientific, Pittsburgh, PA). Total carbon (C) was determined with a C and N analyzer (Vario MAX CN Macro Elemental Analyzer; Elemental Analysensystem GmbH, Hanau, Germany). Particle composition of the soil sample was determined with the micropipette method (Miller and Miller, 1987). Soil surface pH varied greatly across the 11 sites, and ranged from 4.4 to 8.1 (Table 2). Clay content of the soil samples ranged from 19 to 81 g kg-1. Dissolved Cu and Zn loads in runoff for each runoff event were determined as a product of mean metal concentration and discharge rate of the runoff event.
Five different extraction methods were used to extract soil labile Cu and Zn: (i) 0.01 mol L-1 CaCl2–extractable Cu and Zn (1:10 ratio of soil to 0.01 mol L-1 CaCl2; 60-min reaction time; Kuo, 1996), extracting only water-soluble Cu and Zn; (ii) Mehlich 1–extractable Cu and Zn (1:4 ratio of soil to 0.05 mol L-1 HCl + 0.0125 mol L-1 H2SO4; 5-min reaction time; Reed and Martens, 1996), including water-soluble, exchangeable, and partially CaCO3–associated Cu and Zn; (iii) DTPA–TEA-extractable Cu and Zn (1:2 ratio of soil to DTPA–TEA extraction solution; 120-min reaction time; Reed and Martens, 1996), including water-soluble, exchangeable, and partially organic–associated Cu and Zn; (iv) 1 mol L-1 NH4OAc–extractable Cu and Zn (1:4 ratio of soil to 1 mol L-1 NH4OAc extraction solution; 60-min reaction time; Reed and Martens, 1996), including water-soluble and exchangeable Cu and Zn; and (v) Mehlich 3–extractable Cu and Zn (1:10 ratio of soil to Mehlich 3 extraction solution [0.2 mol L-1 CH3COOH + 0.25 mol L-1 NH4NO3 + 0.015 mol L-1 NH4F + 0.013 mol L-1 HNO3 + 0.001 mol L-1 EDTA, pH 2.0]; 5-min reaction time; Mehlich, 1984), including water-soluble, exchangeable, partially CaCO3, and organic–associated Cu and Zn. After each extraction, the suspension was centrifuged at 7500 x g for 30 min and then the supernatant was passed through Whatman #42 filter paper. Copper and Zn concentrations in the supernatant after centrifugation were determined by the ICP–AES. The detection limits of the ICP–AES are 2.50 and 0.60 µg L-1, respectively, for Cu and Zn. Data analyses were conducted with SAS program procedures (SAS Institute, 1998).
|
RESULTS AND DISCUSSION
|
|---|
Extractable Soil Copper and Zinc
Extractable soil Cu and Zn concentrations varied greatly with soils and extractants (Table 3). Extracted Cu and Zn concentrations with five extractants decreased in the order of Mehlich 1 > Mehlich 3 > DTPA–TEA > 1 mol L-1 NH4OAc > 0.01 mol L-1 CaCl2. Mean extracted metal concentrations with 1 mol L-1 NH4OAc, Mehlich 3, DTPA–TEA, Mehlich 1, and 0.01 mol L-1 CaCl2 were 25, 20, 9.4, 0.5, and 0.2 mg kg-1 for Cu and 19, 7.7, 2.4, 0.6, and 0.5 mg kg-1 for Zn, respectively. The highest extracted Cu and Zn concentrations occurred at Site 11, whereas the lowest extracted metal concentrations occurred at Site 7 for 0.01 mol L-1 CaCl2–extractable Cu and Zn, and Site 10 for 1 mol L-1 NH4OAc–, Mehlich 3–, DTPA–TEA-, and Mehlich 1–extractable Cu and Zn.
Copper and Zinc Concentrations in Runoff
Dissolved Cu concentrations in the runoff water in 2001, ranging from nondetectable to 1475 µg L-1, varied between sampling sites and among the runoff events (Fig. 2)
. Among all 697 runoff water samples, 8% of the samples exceeded the highest value (280 µg L-1) of Cu observed in a published assessment of natural surface waters of the USA (Manahan, 1991), 82% of the samples had dissolved Cu < 150 µg L-1, while 1% of the samples had dissolved Cu > 1000 µg L-1, a limit value for Cu in drinking water (United States Public Health Service, 1962). Mean dissolved Cu concentration of all runoff water samples was 112 µg L-1, which was much higher than the average (15 µg Cu L-1) for natural surface waters in the USA (Manahan, 1991). Mean dissolved Cu concentrations for each sampling site varied from a low of 5 µg L-1 (Site 4) to 550 µg L-1 (Site 10) (Fig. 2). The dissolved Cu concentration in runoff water samples within an individual site varied greatly, with coefficients of variation from 17% (Site 1) to 120% (Site 4). Dissolved Zn concentrations in runoff water for all samples ranged from 1 to 720 µg L-1 with a mean of 50 µg L-1. This mean value is slightly below the average (64 µg Zn L-1) for natural surface waters in the USA (Manahan, 1991). All samples had Zn < 5000 µg L-1, the maximum permissible value for Zn in U.S. drinking water (United States Public Health Service, 1962). About 73% of the samples had dissolved Zn < 50 µg L-1. There was a significant correlation between concentrations of dissolved Cu and Zn in the runoff water (r = 0.77, significant at the 0.01 probability level; n = 697), probably due to simultaneous accumulation of Cu and Zn in the soils.
View larger version (24K):
[in this window]
[in a new window]
|
Fig. 2. Variations of Cu and Zn concentrations in runoff from 11 field sites in 2001. The term n refers to the number of water samples. Standard deviations are placed above each bar.
|
|
The variation of Cu and Zn concentrations in runoff water was probably associated with differences in soil-extractable Cu and Zn levels and rainfall for each runoff event. The differences in dissolved Cu and Zn concentrations in the runoff water among 11 sites (Fig. 2) may partially be explained by the variation in extractable Cu and Zn levels (Table 3). Changes of mean dissolved Cu and Zn in six sequentially collected runoff water samples for 11 and 13 complete runoff events at Sites 1 and 9 are presented in Fig. 3
. Mean dissolved Cu in runoff from either Site 1 or Site 9 tended to decrease slightly with the sampling sequence, whereas mean Zn concentration tended to increase slightly with sampling sequence (Fig. 3). However, the differences in the mean Cu and Zn concentrations among the six sequentially collected runoff water samples were not significant. The variation among six sequential samples was much smaller, as compared with variation of dissolved Cu and Zn concentrations among 11 runoff events (Site 1) or 13 runoff events (Site 9). These results suggest that variation of dissolved Cu and Zn concentration at the same site result mainly from different rainfall events, probably affected by rainfall intensity, volumes of runoff, agricultural practices (spraying or fertilization), and seasonal variation (dry season or rainy season).
View larger version (22K):
[in this window]
[in a new window]
|
Fig. 3. Mean soluble Cu and Zn concentrations in six sequential samples of runoff water. The term n = 11 and 13 for Sites 1 and 9, respectively. Bars represent standard deviations.
|
|
Copper and Zinc Concentrations in Runoff in Relation to Extractable Soil 9Copper and Zinc
The correlation coefficients (r) between extractable Cu and Zn and mean dissolved Cu and Zn concentrations in runoff are presented in Table 4. The correlation between extractable Cu and Zn and dissolved Cu and Zn in surface runoff depended on the extraction methods. The extractable Cu obtained by 0.01 mol L-1 CaCl2, Mehlich 1, and DTPA–TEA extraction methods were significantly correlated with mean dissolved Cu in field runoff water. The highest correlations of dissolved Cu concentrations in runoff were obtained when soil Cu was extracted by 0.01 mol L-1 CaCl2 (r = 0.89, Table 4). The extractable Cu obtained by 1 mol L-1 NH4OAc and Mehlich 3 extraction methods was not significantly correlated to dissolved Cu in field runoff water. Dissolved Zn in field runoff water was only significantly correlated with extractable Zn by 0.01 mol L-1 CaCl2 (r = 0.89, Table 4). There were no significant correlations between dissolved Zn in site runoff water and extractable Zn by Mehlich 1, DTPA–TEA, 1 mol L-1 NH4OAc, and Mehlich 3 extraction methods (Table 4). The results suggest that soils with higher dissolved Cu and Zn have a greater potential to release Cu and Zn into runoff waters. This may be due to a fact that the 0.01 mol L-1 CaCl2 test is the closest approximation of the "pool" of Cu and Zn in the soil that is susceptible to loss. Apparently, the Cu and Zn in the runoff came mainly from soil water-soluble Cu and Zn, which was extractable by 0.01 mol L-1 CaCl2.
View this table:
[in this window]
[in a new window]
|
Table 4. Correlation coefficients (r) between mean concentrations of Cu and Zn in runoff from 11 field sites in 2001 and extractable Cu and Zn extracted by different methods in soils (n = 11).
|
|
Dissolved Copper and Zinc Loads in Runoff
Differences in rainfall in 2001 among the 11 sites were minimal (Table 1), but total runoff discharge varied from 522 to 5268 m3 ha-1 (Fig. 4)
. The highest discharge was 10 times the lowest. Site 10 had higher runoff discharge whereas Sites 1, 2, 5, and 6 had lower runoff discharge. The difference in runoff discharge may be due to variation of soil permeability (Table 1). Except for Sites 6, 8, and 11, runoff discharge for each runoff event was significantly correlated with corresponding rainfall (Table 5). The results indicated that surface runoff drainage for each rainfall event in most of experimental sites was related with amount of the rainfall.
View this table:
[in this window]
[in a new window]
|
Table 5. Correlation coefficients (r) among rainfall, runoff discharge, and Cu and Zn loads for each runoff event in different individual sites.
|
|
Dissolved Cu and Zn loads in surface runoff varied with the sites (Fig. 4). Total dissolved Cu load in 2001 in surface runoff ranged widely from 8.9 to 547.8 g ha-1 with the highest load at Site 11 and the lowest at Site 6. The highest load was 61 times the lowest. Total dissolved Zn load in runoff ranged from 10.8 to 283.0 g ha-1 with the highest at Site 9 and the lowest at Site 5. The highest load was 26 times the lowest. For each individual site, Zn load in each runoff even was significantly correlated with Cu load (Table 5), indicating that losses of Cu and Zn from the sites were in a similar trend. Copper and Zn loads were more correlated with runoff discharge than rainfall (Table 5).
Multiple linear regressions between total runoff Cu and Zn loads at each site and total runoff discharge, and 0.01 mol L-1 CaCl2–extractable soil Cu and Zn levels indicated that both the runoff discharge and 0.01 mol L-1 CaCl2–extractable Cu and Zn levels had significant influences on total Cu and Zn loads. Multiple linear regression equations between total runoff Cu and Zn loads (Y1, Y2, g ha-1) at each site and total runoff discharge (X1, m3 ha-1), 0.01 mol L-1 CaCl2–extractable soil Cu (X2, mg kg-1), and Zn (X3, mg kg-1) were as follows:
 |
 |
The runoff discharge and 0.01 mol L-1 CaCl2–extractable Cu level accounted for 81% of the total variations in the Cu load, of which 0.01 mol L-1 CaCl2–extractable Cu and runoff explained 47 and 34% the total variation, respectively. The runoff discharge and 0.01 mol L-1 CaCl2–extractable Zn level accounted for 67% of the total variations in the Zn load, of which 0.01 mol L-1 CaCl2–extractable Zn and runoff explained 28 and 39% the total variation, respectively. The results suggest that the 0.01 mol L-1 CaCl2–extractable Cu and Zn and runoff discharge are the important factors influencing metal runoff losses from agricultural land.
|
CONCLUSIONS
|
|---|
The results of this study provide evidence of a positive correlation between amounts of extractable Cu and Zn and dissolved Cu and Zn concentrations in runoff from sandy agricultural soils. However, extractable Cu and Zn were correlated more with concentrations of dissolved Cu and Zn in runoff when the soil Cu and Zn were extracted with 0.01 mol L-1 CaCl2. Our data suggest that 0.01 mol L-1 CaCl2 is the best extractant for predicting concentrations of Cu and Zn in runoff water. Further investigations are needed to determine whether a similar relationship exists with other soils and whether the values of CaCl2–extractable Cu and Zn are reliable as universal predictors of dissolved Cu and Zn concentrations in runoff from agricultural fields. The Cu and Zn losses in surface runoff were positively correlated with runoff discharge and soil-extractable Cu and Zn levels. The runoff discharge and 0.01 mol L-1 CaCl2–extractable soil Cu level could explain 81% of total variation in runoff Cu losses whereas the runoff discharge and 0.01 mol L-1 CaCl2–extractable soil Zn concentration could explain 67% of total variation in runoff Zn losses in runoff.
|
ACKNOWLEDGMENTS
|
|---|
This study was, in part, supported by a section 319 Nonpoint Source Management Program grant (DEP Contract #WM746) from the USEPA through a contract with the Nonpoint Source Management/Water Quality Standard Section of the Florida Department of Environmental Protection (FDEP), by a grant (#2002CB410804) from the Science and Technology Ministry of China, and by a grant (DEP Contract #SP566) from the FDEP. This manuscript is Florida Agricultural Experiment Station Journal Series no. R-08953.
|
NOTES
|
|---|
1 Mention of particular companies or commercial products does not imply recommendations or endorsement by the Zhejiang University or the University of Florida over other companies or products not mentioned. 
|
REFERENCES
|
|---|
- Adriano, D.C. 1989. Trace elements in the terrestrial environment. Springer-Verlag, New York.
- Alloway, B.J. (ed.) 1995. Heavy metals in soils. Blackie Academic & Professional, London.
- Alva, A.K. 1992. Micronutrient status of Florida soils under citrus production. Commun. Soil Sci. Plant Anal. 23:2493–2510.
- Bunzl, K., M. Trautmannsheimer, P. Schramel, and W. Reifenhauser. 2001. Availability of arsenic, copper, lead, thallium, and zinc to various vegetables grown in slag-contaminated soils. J. Environ. Qual. 30:934–939.[Abstract/Free Full Text]
- Cezary, K., and B.R. Singh. 2001. Fractionation and mobility of copper, lead, and zinc in soil profiles in the vicinity of a copper smelter. J. Environ. Qual. 30:485–492.[Abstract/Free Full Text]
- Edwards, D.R., P.A. Moore, Jr., T.C. Daniel, P. Srivastava, and D.J. Nichols. 1997. Vegetative filter strip removal of metals in runoff from poultry litter–amended fescuegrass sites. Trans. ASAE 40:121–127.
- Elliott, H.A., M.R. Liberati, and C.P. Huang. 1986. Competitive adsorption of heavy metals by soils. J. Environ. Qual. 15:214–219.[Abstract/Free Full Text]
- Han, F.X., W.L. Kingery, H.M. Selim, and P.D. Derard. 2000. Accumulation of heavy metals in a long-term poultry waste–amended soil. Soil Sci. 165:260–268.
- Hesterberg, D., J. Bril, and P. Del Castilho. 1993. Thermodynamic modeling of zinc, cadmium, and copper solubilities in a manured acidic loamy-sand topsoil. J. Environ. Qual. 22:681–688.[Abstract/Free Full Text]
- Iyengar, S.S., D.C. Martens, and W.P. Miller. 1981. Distribution and plant availability of soil zinc fractions. Soil Sci. Soc. Am. J. 45:735–739.[Abstract/Free Full Text]
- Jorgensen, S.S. 1991. Mobility of metals in soils. Folia Geogr. Danica 19:104–114.
- Kingery, W.L., C.W. Wood, D.P. Delaney, J.C. Williams, and G.L. Mullins. 1994. Impact of long-term application of broiler litter on environmentally related soil properties. J. Environ. Qual. 23:139–147.
- Kuo, K. 1996. Phosphorus. p. 869–919. In D.L. Sparks (ed.) Methods of soil analysis. Part 3. Chemical methods. SSSA Book Ser. 5. SSSA, Madison, WI.
- Li, M., N.V. Hue, and S.K.G. Hussain. 1997. Changes of metal forms by organic amendments to Hawaii soils. Commun. Soil Sci. Plant Anal. 28:381–394.
- Manahan, S.E. 1991. Environmental chemistry. 5th ed. Lewis Publ., Chelsea, MI.
- Maskall, J., K. Whitehead, and I. Thornton. 1995. Heavy metal migration in soils and rocks at historical smelting sites. Environ. Geochem. Health 17:127–138.
- Mehlich, A. 1984. Mehlich No. 3 soil test extractant: A modification of Mehlich No. 2 extractant. Commun. Soil Sci. Plant Anal. 15:1409–1416.
- Miller, W.P., and D.M. Miller. 1987. A micro-pipette method for soil mechanical analysis. Commun. Soil Sci. Plant Anal. 18:1–15.
- Moore, P.A., Jr., T.C. Daniel, J.T. Gilmour, B.R. Shreve, D.R. Edwards, and B.H. Wood. 1998. Decreasing metal runoff from poultry litter with aluminum sulfate. J. Environ. Qual. 27:92–99.
- Payne, G.G., D.C. Martens, C. Winarko, and N.F. Perera. 1988. Availability and form of copper in three soils following eight annual applications of copper-enriched swine manure. J. Environ. Qual. 17:740–746.[Abstract/Free Full Text]
- Purves, D. 1985. Trace element contamination of the environment. Elsevier Science, New York.
- Reed, S.T., and D.C. Martens. 1996. Copper and zinc. p. 703–722. In D.L. Sparks (ed.) Methods of soil analysis. Part 3. Chemical methods. SSSA Book Ser. 5. SSSA, Madison, WI.
- SAS Institute. 1998. SAS user's guide. SAS Inst., Cary, NC.
- Scokart, P.O., K. Meeus-Verdinne, and R. Deborger. 1983. Mobility of heavy metals in polluted soils near Zn smelters. Water Air Soil Pollut. 20:451–463.
- Simonne, E.H., and G.J. Hochmuth. 2001. Soil and fertilizer management for vegetable production in Florida. p. 3–14. In D.N. Maynard and S.M. Olsen (ed.) Vegetable production guide for Florida. Univ. of Florida Coop. Ext. Serv., Gainesville.
- Sims, J.T., and J.S. Kline. 1991. Chemical fractionation and plant uptake of heavy metals in soils amended with co-composed sewage sludge. J. Environ. Qual. 20:387–395.[Abstract/Free Full Text]
- Sims, J.T., and D.C. Wolf. 1994. Poultry manure management: Agricultural and environmental issues. Adv. Agron. 52:1–83.
- Turer, D., J.B. Maynard, and J.J. Sansalone. 2001. Heavy metal concentration in soils of urban highways: Comparison between runoff and soil concentrations at Cincinnati, Ohio. Water Air Soil Pollut. 132:293–314.
- United States Public Health Service. 1962. Public health service drinking water standards. USPHS, Washington, DC.
- Van der Watt, H.V.H., M.E. Sumner, and M.L. Cabrera. 1994. Bioavailability of copper, manganese, and zinc in poultry litter. J. Environ. Qual. 23:43–49.
Related articles in JEQ:
- This Issue in Journal of Environmental Quality
JEQ 2003 32: 745-750.
[Full Text]
This article has been cited by other articles:
|
|
|
|
 
Z. L. He, M. Zhang, X. E. Yang, and P. J. Stoffella
Release Behavior of Copper and Zinc from Sandy Soils
Soil Sci. Soc. Am. J.,
August 22, 2006;
70(5):
1699 - 1707.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Z. L. He, M. K. Zhang, D. V. Calvert, P. J. Stoffella, X. E. Yang, and S. Yu
Transport of Heavy Metals in Surface Runoff from Vegetable and Citrus Fields
Soil Sci. Soc. Am. J.,
September 1, 2004;
68(5):
1662 - 1669.
[Abstract]
[Full Text]
[PDF]
|
|
|
TOP
ABSTRACT
INTRODUCTION
