Origin and Spatial Distribution of Cadmio in Farms Cacaoteras in the Province of Manabí, Ecuador
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Annals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
Origin and Spatial Distribution of Cadmio in Farms
Cacaoteras in the Province of Manabí, Ecuador
Frank Guillermo Intriago-Flor. Universidad Técnica de Manabí. Facultad de Ciencias
Zootécnicas. Km 2 ½ vía Boyacá-Chone. Manabí, Ecuador, e-mail:
frank.intriago@utm.edu.ec; orcid: https://orcid.org/0000-0002-0377-1930
Maritza Viviana Talledo-Solórzano. Universidad Técnica de Manabí. Facultad de Ciencias
Zootécnicas. Km 2 ½ vía Boyacá-Chone. Manabí, Ecuador, e-mail:
mtalledo4282@utm.edu.ec; orcid: https://orcid.org/0000-0002-5735-9490
José Ricardo Macías-Barberán. Universidad Técnica de Manabí. Facultad de Ciencias
Zootécnicas. Km 2 ½ vía Boyacá-Chone. Manabí, Ecuador, e-mail:
ricardo.macias@utm.edu.ec; orcid: https://orcid.org/0000-0002-7900-2222
Gerardo José Cuenca-Nevárez. Universidad Técnica de Manabí. Facultad de Ciencias
Zootécnicas. Km 2 ½ vía Boyacá-Chone. Manabí, Ecuador, e-mail:
gerardo.cuenca@utm.edu.ec; orcid: https://orcid.org/0000-0002-1128-3013
Juan Carlos Menjivar-Flores. Universidad Nacional de Colombia. Facultad de Ciencias
Agrarias, Carrera. 32 #12. Valle del Cauca, Colombia, e-mail: jcmenjivarf@unal.edu.co;
orcid: https://orcid.org/0000-0002-0985-7778
Abstract
Thecultivation of cocoa is of great economic importance to many producing countries
Chocolates and other by-products are made from cocoa beans, but their marketing is
threatened by the presence of heavy metals. In the present study, the cadmium (Cd) content
of soils and its presence in cocoa beans in the province of Manabí in Ecuador were evaluated.
A total of 181 cocoa farms were selected soil samples, irrigation water, organic fertilizer,
leaves and almonds were analyzed to determine the origin, content and spatial distribution of
Cd. For the extraction and determination of the Cd, the standards 3050B USEPA and 6010C
were used by means of spectrometry by ICP-OES ICAP respectively. The data were
analyzed by descriptive statistics and Pearson correlation using SAS/STAT version
9.4.The results showthe presence of Cd in analyzed parts presenting the following order:
Leaf Cd > Almond Cd > Cd soil. Cd content presented positive correlation for organic
matter, N, P, K, Mn, Zn; leaf and almond Cd content presented positive correlation for
bulk density, clay, field capacity, permanent wilt point, Mg, CIC and Ca respectively.
Keys words: Organic farming, contaminant, heavy metal, Theobroma cacao
Introduction
Soil degradation is related to the excessive use of fertilizers, pesticides, burning of harvest
residues and the use of heavy machinery (Santana et al., 2015), on the other hand, it is
necessary to highlight a special type of degradation which is produced by the presence of
harmful chemical substances, which can accumulate in the soil causing its contamination,
such is the case of Cadmium (Cd) (Pereira et al., 2017).
The origin of Cd in agricultural soils occurs in two ways, anthropogenic and geogenic, both
can contaminate soils through different processes (Tran & Popova, 2013), in that order of
ideas, at the level of Latin America agricultural soils present different Cd levels, in Peru and
Venezuela in soils cultivated with cocoa and at a depth of 5-20 cm, levels of 0.79 ppm were
found (Arévaloet al., 2016), and 1.71 ppm of Cd (Pedraza&Huauya , 2017), respectively, on
the other hand, in soils of the Santander Colombia area, levels 2.76 ppm are reported
15142
http://annalsofrscb.ro
Annals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
(Bravo& Benavides, 2020), in southern Ecuador studies carried out by Chávez et al,. (2015),
where the concentration of Cd in 19 farms was monitored, it was found that in the 12 farms at
depths of 0-15 cm they presented accumulation of Cd due to various anthropogenic activities.
The interest in studying Cd in soils cultivated with cocoa arises from the fact that in 2012, the
European Food Safety Authority (EFSA) issued an alert where it is recommended that
chocolate with an amount greater than or equal to 50% solids of cocoa should contain a
maximum of 0.3 ppm of Cd (Zug et al.,2019), the amendment to European regulation No.
1881/2006, which establishes the maximum levels of Cd for chocolate and cocoa-derived
products considering as ranges from 0.10 to 0.80 ppm (Meter et al., 2019).
Cocoa producing countries are concerned about the presence of this element in cultivated
almonds (Durango et al., 2019) in the African continent specifically in Ghana, 0.32 mg.kg-1
has been reported in almonds (FAO, 2018), and 0.09 mg.kg-1 (Bertoldi et al., 2016). In the
same sense, Ecuador, as a producer of fine flavor and aroma cocoa, is also on alert, the
presence of this element at high levels would affect exports to the international market,
possibly reducing revenues by 180 million dollars, which it would affect 51 thousand farmers
(Veco-Andino, 2015). In that order of ideas and given the historical importance of cocoa
cultivation in Ecuador, the need arises to determine the origins, content and spatial
distribution of the Cd present in the soils, in the irrigation water, fertilizers, in the foliar and
almond partcocoa.
Materials and methods
The research was carried out in the north central zone of the province of Manabí 0º 49 ”23”
South Latitude, 80º 11 ”01” West Longitude, at an altitude of 20 m.a.s.l., 181 cocoa-
producing farms were selected for them, these are located on soils developed from different
geologies (Aguirre, 2005). The soils were classified as Udic, HapludoitFluventic which are
deep soils of variable texture (dominant loam) and Ustic, UstropeptVetic (Reyna et al.,
2018).
To determine the origin of the Cd, samples of soils, fertilizers, waters, leaves and cocoa beans
were taken as follows: Soil sampling was carried out at a depth of 20 cm, following the
INIAP methodology, (2016). The irrigation water sample was collected at the water entry
points to the farm using clean and sterile 200 ml plastic containers, in order to preserve the
sample, it was acidified between pH 1 to 2 with nitric acid, (NTE INEN 2169, 2013). From
the organic fertilizer, random composite samples of 1 kg of each fertilizer were taken
(AgroCalidad, 2015), it was placed in a previously identified ziploc-type sleeve and taken to
the laboratory for the determination of total Cd+2. The foliar sampling was carried out
according to the proposal of Puenteset al., (2014). The almond samples of the National-type
Creole cocoa varieties (90%) and 10% of the EET-type clones, were taken according to the
methodology of Rivera (2013), for this, 20 mature pods were harvested.
To determine the total Cd in soil, irrigation water, fertilizer, foliar and almond, an acid
digestion with HNO3 + HCl was performed and it was quantified by ICP ICAP 7200
spectrometry under the EPA 6010C Standard. The texture was determined by the Robinson
pipet method (USDA, 2002), the pH and electrical conductivity (conductivity meter) were
measured in deionized water (soil/water ratio 1:2) using a multiparametric (HANNA HI9829)
(Chávez et al., 2015). For the determination of organic matter, the oxidation method with
potassium dichromate (K2Cr2O7) by Walkey Black (1947), modified by Embrapa (2009),
15143
http://annalsofrscb.roAnnals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
(Rojas et al., 2018) was used. The cation exchange capacity was determined with 1N
ammonium acetate at pH 7. For the determination of Zn and Mn, the digestion method with
6M nitric perchloric HCl was used and the determination by the atomic absorption
spectrophotometry method (Rodríguez & Rodríguez, 2011).
The elaboration of the map of the spatial distribution of Cd in soils, leaves and almonds was
carried out with ArcMap 10.4.1. The semivariograms, were adjusted using the exponential
model proceeding to carry out the interpolation using a normal Kringing log (Argüelloet al.,
2019). The results were subjected to a descriptive statistical analysis (mean, mode, variance,
standard deviation and coefficient of variation), a Pearson correlation analysis and multiple
regression between the Cd contents in soils, foliar and almonds and the physical-chemical
properties of the soil.
Results and Discussion
Characterization of the study area
The sizes of the sampled farms range from 0.25 to 10.00 hectares, of these 60% are in the
Bolívar canton where Tertiary-age rocks predominate and to a lesser extent quaternary
deposits, the remaining 40% are established in the cantons Chone, Portoviejo and Tosagua
where quaternary geological formations predominate (IEE, 2013). The average annual
temperature for the last five years is 26 ºC, with an evapotranspiration of 1256 mm and
precipitation of 762 mm.
Analysis of soil properties
The low variation of the apparent density (13.35) is very similar to those found by Peña et al.,
(2009), cited by Rodríguez (2015) in Inceptisols de Colombia, similar conditions present the
percentage of porosity (6.015), Not so for the humidity, clay and the capacity of water stored
by the soil that present a high variation, these tendencies show an excellent porous space, low
infiltration speed and increase in the capacity of retention of humidity in the soil
(Delgadillo&Pérez, 2016).
Table 1.Descriptive analysis of the physical properties of the soil in the study area.
Standard Variationcoefficient
Variable Mean (%)
deviation
ApparentDensity 1.38 0.184 13.350
PorosityPercentage 46.17 2.777 6.015
Field Capacity 25.27 6.468 25.591
Permanentwiltingpoint 12.55 4.945 39.378
Storablewatersheet 88.74 22.539 25.398
Nine textural classes were found where the most dominant is loam with 37%, second with
clay loam (22%), silty loam (12%), silty clay loam (10%), sandy loam (9%), clay (6%), silty
clay (4%), sandy (1%), the distribution of the particles presented loamy soils, with good
porous space and do not present degradation by compaction, in addition they maintain an
optimal water storage sheet for soils with cocoa crops.
15144
http://annalsofrscb.roAnnals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
On the other hand, it is highlighted that 88.39% of the farms studied the soil pH was neutral,
10% presented slight alkalinity. In 22% of the farms the organic matter values were higher
than 3%, 40% have values between 2-3% and 38% below 2%.
According to Puenteset al., (2014) an optimal cation exchange capacity for cocoa is 19.40
cmol.kg-1, in this order of ideas 73% of the farms have higher values and 27% of the farms
have values lower than those reported.
Cadmium content in soil, leaves, almonds, irrigation water and organic fertilizer
The accumulation of Cd in the soils showed mean values of 0.628 mg.kg-1 lower than the
critical level established by the soils of the Junta de Andalucía where the permissible
concentrations are 2 mg.kg-1 (Galánet al., 1999), meanwhile this value is considered higher
than the critical level established by USEPA, (2002) for agricultural soils in the United States
(0.43 mg kg-1).
In figure 1, the spatial distribution of the Cd content is presented, it is observed that the
higher concentrations of 0.825 to 1.97 mg.kg-1 are found in the north center of the study area.
Figure 1.Spatial distribution of the Cd content in soils.
In Figure 2, the trend of the mean Cd content in the soils, leaves and almonds is observed,
when dividing the study area into four sectors. The average Cd content in cocoa leaves was
1.25 mg.kg-1, being higher than the values of Cd in grain and Cd in soil, this trend was also
observed in studies carried out by Gramlichet al., (2017) for two varieties and four cocoa
production systems in Bolivia. It is necessary to emphasize that in the study carried out the
Cd values in the Nacional variety in leaf are lower than those reported by Barrazaet al.,
(2017) in the EET 116 clone in the Portoviejo area.
15145
http://annalsofrscb.roAnnals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
4
3.5
0.61
3
Cd (mg.kg-1)
2.5 0.69 0.58
0.68
2 1.75
1.5 1.18 1.14
1.03
1
0.5 1.18 0.87 0.93 1.05
0
North South East West
Sites
Cd grain Cd leaf Cd soil
Figure 2.Distribution of the content of Cd+2 in the study area.
For the European Food Safety Authority (EFSA), the permissible limits of Cd are 0.1 to 0.80
mg.kg-1 for different types and proportions of cocoa in chocolate production (Engbersenet al.,
2019). In 60% of the farms studied, the Cd content was found in a range of 0.8 to 2.74 mg.kg-
1
, these concentrations are higher than the permissible levels, with an average of 0.99 mg.kg-1
of Cd in the cocoa bean, are distributed in the central zone and with 2% of the farms with
minimum values towards the south eastern zone of the study area as shown in Figure 3.
The Cd contents in the different parts analyzed present the following order: Cd leaf> Cd
grain> Cd in soils, the same behavior pattern was found in other studies on Cd in cocoa
(Gramlichet al., 2017; Llatanceet al., 2018;Ramtahlet al., 2016; Rodríguez et al., 2019;
Romero-Estévez, 2019).
Figure
3.Spatial distribution of the Cd+2 content in cocoa beans.
The farms under study use compost-type fertilizers that are made with raw materials from the
area and that are applied at a ratio of 3.2 t ha-1, this presented an average Cd concentration of
0.277 mg kg-1, they are considered low levels due to the criterion of European regulations
through Regulation (EC) No. 1069/2009 that the concentration limits for Cd in compost
should not be greater than 0.7 mg kg-1 of Cd, Fernández (2018), but are permissible between
a range of 0.01 to 1.00 mg kg-1, Salmanzadehet al., (2016), establish that the continuous
15146
http://annalsofrscb.roAnnals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
application of organic fertilizers in the long term will result in the accumulation of Cd in the
soils, this aspect must be monitored in the study area.
Irrigation water presented average Cd contents of 0.333 g L-1 considered high because they
exceed the permissible limits of 0.05 g L-1 (Pozo, 2017), according to Mancillaet al., (2012),
the presence of heavy metals in irrigation water represents a problem for agriculture due to
the accumulation in agricultural soils, in that order of ideas in the study area, the use of water
for irrigation and the application of fertilizer organic compost-type accounts for 10% and 8%
respectively, which can be long-term sources of availability and accumulation of Cd in the
soil and therefore its presence in leaves and cocoa beans.
Argüelloet al., (2019), express that the concentration of total soil Cd has a positive
relationship with the use of irrigation, pesticides, organic agriculture and forestry, the
application of compost and pruning did not significantly affect the soil Cd, in the same vein,
Carrillo (2016), expresses that chicken manure, fermented organic fertilizers known as
bokashi and in compost the Cd content remain below 2.5 mg kg-1Nziguheba and Smoders
(2008). In figure 4 the average behavior of the Cd content for soil, foliar (leaves), almond,
irrigation water and fertilizer can be observed.
2.5Annals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
however, considering that 67% of cocoa farms have low Zn levels, it is possible, according to
Alloway (2013), that Zn deficiency in the soil stimulates Cd uptake by plants.
The Cd content in the leaf has a positive correlation with the CEC, and this with the clays,
similar results reported by Gramlichet al., (2018), when finding a positive relationship
between the Cd of the leaf and the clays in soils with a clay texture in organic agroforestry
production systems, in that order of ideas, the content of Cd in the leaf shows a correlation
with Ca and Mg in soils, at the increasing these in the exchange sites, increases their
concentration in the soil and the Cd content in the leaves and in the cocoa beans Huang et al.,
(2017), and Österas and Greger (2006).
The Cd contents in the bean showed a positive correlation (0.578) with the Cd content in the
leaf, as the accumulation of Cd in the leaf increases, the translocation of Cd to the cocoa
kernel increases, these results coincide with studies carried out in Trinidad and Tobago and
Colombia where very close correlations were found between the Cd content of the leaf and
the cocoa grain (Ramtahalet al., 2016, Rodríguez et al., 2019), this in contrast to Chávez et
al., (2015), found that exceeding 1 mg kg-1 of Cd in the cocoa grain had a high correlation
with the cocoa pod.
Conclusions
The values found in soil, leaves and almonds do not exceed the reference values for Cd,
however, it is advisable to continue monitoring its presence in soil, especially in farms in the
south of the study area. The physical and chemical conditions of the soils are adequate for the
cultivation of cocoa, and it is determined that the presence of Cd in soils and its translocation
to leaves, almonds come from anthropogenic sources, that is, from the use of water for
irrigation and fertilizers in different application rates.
References
1. Agencia Ecuatoriana de Aseguramiento de la Calidad del Agro (AGROCALIDAD).
(2015). Laboratorio de suelos, foliares y aguas: Instructivo para toma de muestras de
foliares. Quito, Ecuador. 9 p.
2. Aguirre, M. (2005). Susceptibilidad al deslizamiento de los suelos y rocas de la
provincia de Manabí. Tesis de Licenciatura. Guayaquil. Espol.
3. Arévalo-Gardini, E., Obando-Cerpa, M. E., Zuñiga-Cernades, L. B., Arévalo
Hernández, C. O., Baligar, V., y He, Z. (2016). Metales pesados en suelos de
plantaciones de cacao (Theobroma cacao L.) en tres regiones del Perú. Ecología
aplicada, 15 (2), 81-89. http://dx.doi.org/10.21704/rea.v15i2.747
4. Argüello, D., Chavez, E., Lauryssen, F., Vanderschueren, R., Smolders, E., Montalvo,
D. (2019). Soil properties and agronomic factors affecting cadmium concentrations in
cacao beans: A nation wide survey in Ecuador. Science of the total Environment. 649:
120-127.http://dx.doi.org/10.1016/j.scitotenv.2018.08.292
5. Alloway B. J. (2013). Heavy metals in soils: Trace metals and metalloids in soils and
their Bioavailability, 3 ed. Springer Science & Business Media.
6. Barraza, F., Schreck, T., Leveque, G., López, F., Prunier, J., Marquet, A., Maurice, L.
(2017). Cadmium bioaccumulation and gastric bioaccesibility in cacao: A field study
in areas impacted by oil activities in Ecuador. Environmental Pollution. 229: 950-
963.http://dx.doi.org/10.1016/j.envpol.2017.07.080
7. Bertoldi, D., Barbero, A., Camin, F., Caligiani, A., y Larcher, R.
(2016).Multielemental fingerprinting and geographic traceability of Theobroma cacao
15148
http://annalsofrscb.roAnnals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
beans and cocoa productos.Food Control. 65, 46-
53.http://dx.doi.org/10.1016/j.foodcont.2016.01.013
8. Bravo. D., y Benavides-Erazo, J. (2020). The use of a Two-Dimensional Electrical
Resistivity Tomography (2D-ERT) as a Technique for Cadmium Determination in
Cacao Crop Soils.AppliedSciences, 10(12), 4149.
http://dx.doi.org/10.3390/app10124149
9. Carrillo, M. (2016). Avances en investigación del Cd en el cultivo de cacao en el
Ecuador. Recuperado de:
http://www.iica.int/sites/default/files/events/presentations/2016-
07/foro_cd_iica_julio_11_2016.pdf
10. Chávez, E., He, Z., Stofella, P., Mylavarapu, R., Moyano, B., Baligar, V. (2015).
Concentration of cadmium in cacao beans and its relationship with soil cadmium in
southern Ecuador.Science of the total environment, 533, 205-
214.http://dx.doi.org/10.1016/j.scitotenv.2015.06.106
11. Delgadillo, O., y Pérez. L. (2016). Medición de la infiltración del agua en el suelo.
Centro Andino para la Gestión y Uso del Agua. Centro AGUA. Facultad de Ciencias
Agrícolas, Pecuarias y Forestales Universidad Mayor de San Simón. Cochabamba,
Bolivia
12. Durango, W., Caicedo, M., Vera, D., Sotomayor, I., Saini, E., Chávez, E. (2019). La
Cadena de Valor del Cacao en América Latina y El Caribe. FONTAGRO, ESPOL,
INIAP. 104 p.
13. Engbersen, N., Gramlich, A., Lopez, M., Schwars, G., Hattendorf, B., Gutierrez, O.,
&Schulin, R. (2019).Cadmium accumulation and allocation in different cacao
cultivars.Science of the Total Environment.678, 660-
670.http://dx.doi.org/10.1016/j.scitotenv.2019.05.001
14. Fernández, L. (2018). Determinación y seguimiento de metales pesados en
componentes de origen del compost. Trabajo de Máster. Universidad de Oviedo. 84 p.
15. Food and AgricultureOrganization of UnitedNations [cita en inglés] (FAO) (2018).
Comisión del Codex Alimentarius sobre normas alimentarias. Roma, Italia. 20 p.
16. Galán, E., Gómez, J., Aguilar, J. (1999). Los criterios y estándares para declarar un
suelo contaminado en Andalucía y la metodología y técnicas de toma de muestra y
análisis para su investigación. Universidades de Granada, Huelva y Sevilla. 257 p.
17. Gramlich, A., Tandy, S., Gauggel, C., López, M., Perla, D., Gonzalez, V., Shulin, R.
(2018). Soil cadmium uptake by cacao in Honduras. Science of the Environment, 612,
370-378. http://dx.doi.org/10.1016/j.scitotenv.2017.08.145
18. Gramlich, A., Tandy, S., Andres, C., Paniagua, JC, Armengot, L., Schneider, M.
&Shulin, R. (2017) Cadmium uptake by cocoa trees in agroforestry and monoculture
systems under conventional and organic management, Sci Total Environ. 580, 677-
686.http://dx.doi.org/10.1016/j.scitotenv.2016.12.014
19. Huang, D., Gong, X., Liu, Y., Zeng, G., Lai, C., Bashir, H., Zhou, L., Wang, D., Xu,
P., Cheng, M., Wan, J. (2017). Effect of calcium at toxic concentrations of cadmium
in plants.Planta 245, 863-873. http://dx.doi.org/10.1007/s00425-017-2664-1
20. Instituto Espacial Ecuatoriano (IEE). (2013). Memoria Técnica: Generación de
Geoinformación para la gestión del territorio a nivel nacional escala 1:25.000. Clima
e Hidrología. 27 p
21. Instituto Ecuatoriano de Normalización (INEN). (2013). Norma Técnica Ecuatoriana
INEN 2169. Agua. Calidad del Agua. Muestreo manejo y conservación de muestras.
26 p.
15149
http://annalsofrscb.roAnnals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
22. Instituto Nacional de Investigaciones Agropecuarias (INIAP). (2016). Metodología
para la determinación de Cd+2 en tejido vegetal. Laboratorio de Suelos y Aguas.
Quevedo, Ecuador. 4 p.
23. Liu, J., Zhang, J., Zhang, F. (2007). Role of iron plaque in Cd uptake by and
translocation within rice (Oryza sativa L) seedlings grown in solution
culture.EnvironmentExperimental. Botanica, 59(3)- 314-320.
http://dx.doi.org/10.1016/j.envexpbot.2006.04.001
24. Mancilla, O.; Ortega, H.; Ramirez, C.; Uscanga, E.; Ramos, R.; Reyes, A. (2012).
Metales pesados totales y arsénico en el agua para riego de Puebla y Veracruz,
México. Revista Internacional de Contaminación Ambiental 28 (1) 39-48.
25. Meter, A., Atkinson, R. J., &Laliberte, B. (2019). Cadmium in Cacao From Latin
America and The Caribbean. A Review of Research and Potential Mitigation
Solutions. Caracas: CAF. Retrieved from
http://scioteca.caf.com/handle/123456789/1506
26. Nziguheba, G., y Smolders, E. (2008). Inputs of trace elements in agricultural soils
via phosphate fertilizers in European countries Sci. Total Environ, 390, 53-57.
http://dx.doi.org/10.1016/j.scitotenv.2007.09.131
27. Österas, A., y Greger, M. (2006). Interactions between calcium and copper or
cadmium in Norway spruce.Biol. Plant. 50, 647. http://dx.doi.org/10.1007/s10535-
006-0101-6
28. Pedraza, E.T., y Rojas, M. Á. H. (2017). Distribución del contenido de cadmio en los
diferentes órganos del cacao CCN-51 en suelo aluvial y residual en las localidades de
Jacintillo y Ramal de Aspuzana. Revista de Investigación en Agroproducción
Sustentable, 1(2), 69-78.
29. Pereira, P., Bogunovic, I., Muñoz-Rojas, M y Brevik, EC. (2018). Soil ecosystem
service, sustaibability, valuation and mangement.Environmental Scienc& Health.5, 7-
13.
30. Pozo, F. (2017). Presencia de metales pesados cadmio y plomo en el estuario del río
Chone Manabí, Ecuador. Ciencia Unemi 10 (24), 123-130.
31. Puentes, Y., Menjivar, J., Aranzazu, F. (2014). Eficiencias en el Uso de Nitrógeno,
32. Fósforo y Potasio en clones de cacao (Theobroma cacao L.). Bioagro 26 (2), 99-106.
33. Ramtahal, G., Yen, I., Bekele, F., Wilson, L., Maharaj, K., Harrynann, L.
(2016).Relationships between cadmium in tissues of cacao trees and soils in
plantation of Trinidad and Tobago.Food Nutri. Sci. 7, 37-43.
http://dx.doi.org/10.4236/fns.2016.71005
34. Reyna, L., Vera, L., Reyna, L. (2018). Soil Organic Carbon concentration and storage
under different land uses in the Carrizal-Chone valley in Ecuador.Appliedscience. 9
(45). http://dx.doi.org/10.3390/app9010045
35. Rivera, S. (2013). Guía de métodos de detección y análisis de Cadmio en cacao
(Theobroma Cacao L). DEVIDA. Lima, Perú. 47 p.
36. Rodríguez, H., Darghan, A., Henao, M. (2019). Spatial regresssion modeling of soils
with high cadmium content in cocoa producing area of Central Colombia.Geoderma
Regional. https://doi.org/10,1016)j.geodrs.2019.e00215
37. Rodríguez, F. (2015). Variabilidad espacial de las propiedades físicas y química en
rendimiento y calidad de Café. (Tesis de maestría). Universidad Nacional de
Colombia. 75 p.
38. Rodríguez, H., & Rodríguez, J. (2011). Métodos de Análisis de Suelos y Plantas:
criterios de interpretación. México. Trillas.
39. Rojas, P., Ramirez, D., Rashe, J., Encina, A. (2018). Niveles de materia orgánica en
distintos tipos de manejo. Brazilian Journal of Development. v. 4, n.7, p.3789-3800.
15150
http://annalsofrscb.roAnnals of R.S.C.B., ISSN:1583-6258, Vol. 25, Issue 6, 2021, Pages. 15142 - 15151
Received 25 April 2021; Accepted 08 May 2021.
40. Romero-Estévez, D., Yánez-Jácome, G.S., Simbaña-Farinango, K., & Navarrete, H.
(2019).Content and the relationship between cadmium, nickel, and lead concetrations
in Ecuadorian cocoa beans from nine provinces.Food control,
106.doi.10.1016/j.foodcont.2019.106750
41. Salmanzadeh, M., Balks, M., Hartland, A., Schipper, L. (2016). Cadmium
accumulation in three contrasting New Zeland soils with the same phosphate fertilier
history.Geoderma. Reg. 7, 271-278. http://dx.doi.org/10.1016/j.geodrs.2016.05.001
42. Sánchez de Rivera, N. S. (2013). Modelización de los procesos químicos relacionados
con la dinámica del cadmio en dos suelos agrícolas de Venezuela. Tesis de
Doctorado. Bárbula, Venezuela. 276 p.
43. Santana, N., Moya, A., Barreiro, P. (2015). La importancia del suelo en la producción
agrícola. “Tierras de Castilla y León: Agricultura”. 231: 26-25.
44. Tran, T., y Popova, L. (2013). Functions and toxicity of cadmium in plants: recent
advances and future prospects. Turkish Journal of Botany. 37: 1-13. doi:10.3906/bot-
1112-16
45. U.S.D.A. (2002).National Soil Survey Center Natural Resources Conservation
Service.Field book for describing and sampling soils.Version 2.0 Salt Lake City.
United States of America.
46. United States Environmental Protection Agency (US EPA), (2002). Supplemental
guidance for developing soil screening levels for superfund sites Available from
http://www. epa.gov/superfund/health/conmedia/soil/index.htm.
47. Veco-Andino. (2016). Exportación de cacao ecuatoriano se ve amenazada por altos
niveles de cadmio. www.andino.veco-ngo.org/es/noticias. Recuperado: 6 de abril de
2017.
48. Zug, K., Yupanqui, H., Meyberg, F., Cierjacks, J. y Cierjacks, A. (2019). Cadmium
Accumulation in Peruvian Cacao (Theobroma cacao L.) and Opportunities for
Mitigation.Water Air Soil Pollut.230 (3), 72.http://dx.doi.org/10.1007/s11270-019-
4109-x
Graphic abstract
The commercialization of cocoa is threatened by the presence of heavy metals
Cd extraction
anddetermination
Soil, irrigation water, 3050B USEPA Standard Descriptive statistics
organic fertilizer, almonds 6010C by spectrophotometry Pearson's correlation
and leaves were analyzed by ICP-OES-ICAP
in 181 cocoa farms Soil physicochemical properties
Variables cocoa farms Statistics
Soil cadmium positive correlation The presence of Cd in
Cadmium leaf, with organic matter N, P, K, Mn, soils, leaves, and
grain, soil Zn almonds comes from
anthropogenic sources,
Cadmium in leaf and almond: uses of irrigation water
density, clay, field capacity, and fertilizers in different
permanent wilting point, Mg, CEC doses
and Ca respectively
15151
http://annalsofrscb.roYou can also read
