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Chavez E, He ZL, Stoffella PJ, Mylavarapu R, Li Y, Baligar VC. Evaluation of soil amendments as a remediation alternative for cadmium-contaminated soils under cacao plantations. Environ Sci Pollut Res Int 2016; 23:17571-17580. [PMID: 27234831 DOI: 10.1007/s11356-016-6931-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 05/19/2016] [Indexed: 06/05/2023]
Abstract
Elevated plant-available cadmium (Cd) in soils results in contamination to cacao (Theobroma cacao L) beans. Effectiveness of vermicompost and zeolite in reducing available Cd in three cacao-growing soils was studied under laboratory conditions. Sorption-desorption experiments were conducted in soils and amendments. Cadmium was added at 0 or 5 mg kg(-1) (spiked), then, amendments were incorporated at 0, 0.5, or 2 %. Amended soils were incubated at room temperature for 28 days. Plant-available Cd was determined using 0.01 M CaCl2 (WSE) and Mehlich 3 (M3) extraction procedures in subsamples taken from individual bags at six time intervals. Soils and amendments displayed different sorption characteristics and a better fit was attained with Freundlich model (R (2) > 0.82). Amendments were ineffective in reducing extractable Cd in non-spiked soils. In Cd-spiked soils, vermicompost at 2 % significantly reduced WSE-Cd (P < 0.01) from 3.36, 0.54, and 0.38 mg kg(-1) to values lower that instrument's detection in all the three soils and significantly diminished M3-extractable Cd (P < 0.05) from 4.62 to 4.11 mg kg(-1) in only one soil. Vermicompost at 0.5 % significantly decreased WSE-Cd (P < 0.01) from 3.04 and 0.31 to 1.69 and 0.20 mg kg(-1), respectively, in two soils with low sorption capacity for Cd. In contrast, zeolite failed to reduce WSE- or M3-extractable Cd in all studied soils. A negative correlation occurred between soil pH and WSE-Cd (r > -0.89, P < 0.01). The decrease in WSE-Cd appears to be associated with the increase in pH of the vermicompost-amended soils.
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Affiliation(s)
- E Chavez
- Indian River Research and Education Center, University of Florida, IFAS, Fort Pierce, FL, 34945, USA
- Escuela Superior Politecnica del Litoral, Facultad de Ciencias de la Vida, Centro de Investigaciones Biotecnologicas del Ecuador, Guayaquil, Ecuador
- Facultad de Ciencias de la Ingenieria, Universidad Estatal de Milagro, Milagro, Ecuador
| | - Z L He
- Indian River Research and Education Center, University of Florida, IFAS, Fort Pierce, FL, 34945, USA.
| | - P J Stoffella
- Indian River Research and Education Center, University of Florida, IFAS, Fort Pierce, FL, 34945, USA
| | - R Mylavarapu
- Soils and Water Science Department, University of Florida, IFAS, Gainesville, FL, 32601, USA
| | - Y Li
- Soils and Water Science Department, University of Florida, IFAS, Gainesville, FL, 32601, USA
| | - V C Baligar
- United State Department of Agriculture, Beltsville Agricultural Research Center, Beltsville, MD, 20705, USA
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Chavez E, He ZL, Stoffella PJ, Mylavarapu RS, Li YC, Baligar VC. Chemical speciation of cadmium: An approach to evaluate plant-available cadmium in Ecuadorian soils under cacao production. Chemosphere 2016; 150:57-62. [PMID: 26891357 DOI: 10.1016/j.chemosphere.2016.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 01/12/2016] [Accepted: 02/02/2016] [Indexed: 06/05/2023]
Abstract
Elevated concentration of cadmium (Cd) in cacao beans has raised serious concerns about the chocolate consumption on human health. Accumulation of Cd in cacao bean in southern Ecuador has been related to soil contamination. In this study, soil fractionation approach was used to identify available Cd pools in the soils and to correlate these Cd pools with bean Cd concentration and soil test indexes. The distribution of soil Cd fractions decreased in the order: oxidizable > acid-soluble > residual > reducible >> water-soluble (+exchangeable). Oxidizable and acid-soluble fractions accounted for 59 and 68% of the total recoverable Cd for the 0-5 and 5-15 cm soil depth, respectively. Acid-soluble fraction was closely related to bean-Cd, with correlation coefficients (r) of 0.70 and 0.81 (P < 0.01) for the 0-5 and 5-15 cm soil depth, respectively. Acid-soluble Cd was significantly correlated with 0.01 M HCl- (r = 0.99, P < 0.01) or Mehlich 3- extractable Cd (r = 0.97, P < 0.01). These results indicate that acid-soluble Cd fraction is an important part of available Cd pool. Since approximately 60% of Cd in the cacao-growing soils is related to the acid-soluble fraction and bound to organic matter, remediation of the contaminated soils should consider to the dynamics of soil pH and organic matter content.
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Affiliation(s)
- E Chavez
- University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, 2199 South Rock Road, Fort Pierce, FL 34945, USA; Escuela Superior Politecnica del Litoral, Facultad de Ciencias de la Vida, Centro de Investigaciones Biotecnologicas del Ecuador, Km 30.5 Via Perimetral, Guayaquil, Guayas, Ecuador
| | - Z L He
- University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, 2199 South Rock Road, Fort Pierce, FL 34945, USA.
| | - P J Stoffella
- University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, 2199 South Rock Road, Fort Pierce, FL 34945, USA
| | - R S Mylavarapu
- University of Florida, Institute of Food and Agricultural Science, Soil and Water Science Department, 171 McCarty Hall, Gainesville, FL 33611, USA
| | - Y C Li
- University of Florida, Institute of Food and Agricultural Science, Tropical Research and Education Center, 18905 SW 280 Street, Homestead, FL 33031, USA
| | - V C Baligar
- United State Department of Agriculture, ARS, 10300 Baltimore Ave., Beltsville, MD 20705, USA
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Chavez E, He ZL, Stoffella PJ, Mylavarapu RS, Li YC, Moyano B, Baligar VC. Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador. Sci Total Environ 2015; 533:205-14. [PMID: 26172587 DOI: 10.1016/j.scitotenv.2015.06.106] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/23/2015] [Accepted: 06/24/2015] [Indexed: 05/17/2023]
Abstract
Cadmium (Cd) content in cacao beans above a critical level (0.6 mg kg(-1)) has raised concerns in the consumption of cacao-based chocolate. Little is available regarding Cd concentration in soil and cacao in Ecuador. The aim of this study was to determine the status of Cd in both, soils and cacao plants, in southern Ecuador. Soil samples were collected from 19 farms at 0-5, 5-15, 15-30, and 30-50 cm depths, whereas plant samples were taken from four nearby trees. Total recoverable and extractable Cd were measured at the different soil depths. Total recoverable Cd ranged from 0.88 to 2.45 and 0.06 to 2.59, averaged 1.54 and 0.85 mg kg(-1), respectively in the surface and subsurface soils whereas the corresponding values for M3-extractable Cd were 0.08 to 1.27 and 0.02 to 0.33 with mean values of 0.40 and 0.10 mg kg(-1). Surface soil in all sampling sites had total recoverable Cd above the USEPA critical level for agricultural soils (0.43 mg kg(-1)), indicating that Cd pollution occurs. Since both total recoverable and M3-extractable Cd significantly decreased depth wise, anthropogenic activities are more likely the source of contamination. Cadmium in cacao tissues decreased in the order of beans>shell>>leaves. Cadmium content in cacao beans ranged from 0.02 to 3.00, averaged 0.94 mg kg(-1), and 12 out of 19 sites had bean Cd content above the critical level. Bean Cd concentration was highly correlated with M3- or HCl-extractable Cd at both the 0-5 and 5-15 cm depths (r=0.80 and 0.82 for M3, and r=0.78 and 0.82 for HCl; P<0.01). These results indicate that accumulation of Cd in surface layers results in excessive Cd in cacao beans and M3- or HCl-extractable Cd are suitable methods for predicting available Cd in the studied soils.
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Affiliation(s)
- E Chavez
- University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945, USA; Escuela Superior Politecnica del Litoral, Centro de Investigaciones Biotecnologicas del Ecuador, Guayaquil, Guayas, Ecuador
| | - Z L He
- University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945, USA.
| | - P J Stoffella
- University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945, USA
| | - R S Mylavarapu
- University of Florida, Institute of Food and Agricultural Science, Soil and Water Science Department, Gainesville, FL 33611, USA
| | - Y C Li
- University of Florida, Institute of Food and Agricultural Science, Tropical Research and Education Center, Homestead, FL 33031, USA
| | - B Moyano
- Escuela Superior Politecnica del Litoral, Centro de Investigaciones Biotecnologicas del Ecuador, Guayaquil, Guayas, Ecuador
| | - V C Baligar
- United State Department of Agriculture, ARS, Beltsville, MD 20705, USA
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Baligar VC, Fageria NK, Paiva A, Silveira A, de Souza JO, Lucena E, Faria JC, Cabral R, Pomella AWV, Jorda J. Light Intensity Effects on Growth and Nutrient-use Efficiency of Tropical Legume Cover Crops. Advances in Agroforestry 2008. [DOI: 10.1007/978-1-4020-6572-9_5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Kamp-Glass M, Powell D, Reddy GB, Baligar VC, Wright RJ. Biotechniques for improving acid aluminum tolerance in alfalfa. Plant Cell Rep 1993; 12:590-592. [PMID: 24201792 DOI: 10.1007/bf00233067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/1993] [Revised: 06/01/1993] [Indexed: 06/02/2023]
Abstract
Alfalfa (Medicago sativa L.), cultivars ARC, Regen Y and Saranac were selected in vitro in a recently developed acid/aluminum toxic media. The new media produced higher initiation rates and higher fresh callus weights than those obtainable with the media described by Meredith and Connor for the selection of aluminum resistant variants in Nicotiana plumbaginofolia. Both rescue and direct initiation yielded adequate amounts of healthy callus for the initiation of embryogenesis. The toxic effect of the acid/aluminum media is expressed in both the percent of explants initiating callus and in the fresh-weights obtained during initiation and two subsequent subcultures.
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Affiliation(s)
- M Kamp-Glass
- N.C. A & T State University, 1601 E. Market St., 27411, Greensboro, N.C., USA
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Fageria NK, Wright RJ, Baligar VC, Carvalho JRP. Upland rice response to potassium fertilization on a Brazilian oxisol. ACTA ACUST UNITED AC 1990. [DOI: 10.1007/bf01087423] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Fageria NK, Baligar VC, Wright RJ, Carvalho JRP. Lowland rice response to potassium fertilization and its effect on N and P uptake. ACTA ACUST UNITED AC 1990. [DOI: 10.1007/bf01087425] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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