Locations In Chile Research Articles

Genetic characterization of blaCTX-M-65 in Salmonella Infantis and blaCMY-2 in Salmonella Heidelberg isolated from fresh ground turkey meat sold in supermarkets in Los Andes and San Felipe, Chile

Annually, food poisoning caused by non-typhoidal Salmonella (NTS) accounts for 40 million foodborne infections worldwide. Outbreaks due to multidrug-resistant NTS strains are associated with the consumption of poultry products. We aimed to determine the proportion of NTS in ground turkey meat available at supermarkets in two locations in Chile, characterizing their serovars, virulence traits, and antimicrobial resistance profiles. Between September and December 2018, we analyzed 47 samples of packed ground turkey meat purchased at 13 supermarkets. NTS were identified by MALDI-TOF, and antimicrobial susceptibility was determined by the disk-diffusion agar method. Whole genome sequencing was performed with MiSeq (Illumina) followed by Nullarbor analysis. NTS was detected in 6 out of 47 samples (12.8 %, 95 %CI: 6.0–25.1 %), identifying S. enterica serovar Infantis (n=4 isolates), serovar Agona (n=1 isolate), and serovar Heidelberg (n=1 isolate), respectively. S. Infantis belonged to sequence type (ST)32, differentiating two clones, whereas the S. Agona was ST13 and S. Heidelberg was ST15. S. Infantis strains were multidrug antibiotic resistant, harboring blaCTX-M-65, tetA, and mutations that confer fosfomycin resistance. Serovars Agona and Heidelberg showed tetracycline (tetB) and fosfomycin resistance (fosA7). Additionally, serovar Heidelberg showed resistance to sulfamethoxazole-trimethoprim, aminoglycosides, and carried the blaCMY-2 gene. This is the first report in Chile about NTS detected in raw ground turkey meat available in supermarkets. S. Infantis and S. Agona strains showed a phylogenetic relationship with strains of the same serovars isolated from the environment in our country. This situation would impact food poisoning and the dissemination of bacterial resistance between animals, humans, and the environment.

Multifunctional Plants: Ecosystem Services and Undervalued Knowledge of Biocultural Diversity in Rural Communities—Local Initiatives for Agroecological Transition in Chile

With the aim of contributing to the understanding of plants’ multifunctionality for sustainable agroecosystem management, the first part of this paper addresses the importance of functional biodiversity in the design of agroecological systems, including the local context in the generation of situated knowledge. The second part describes three participatory research experiences with local farmers across three locations in Chile. The first experience reports on the use of Dasyphyllum diacanthoides (endemic tree) as fodder. A second experience focuses on the establishment of Rosa spp. (invasive species) as an agroforestry system integrated into the landscape. Both experiences were collaborative efforts with farmer communities of the Andean Mountains in southern Chile. The final experience describes the use of different spontaneous aromatic and medicinal plants through biological corridors to encourage beneficial insects as natural controllers. All three research experiences reveal a lack of knowledge, decontextualization, and undervaluation of the biocultural diversity present in some traditional Chilean agroecosystems.

Technical, economic, and CO2 emissions assessment of green hydrogen production from solar/wind energy: The case of Chile

Chile has the potential to become a leading producer of green hydrogen because of its abundance of renewable energy sources. This study has developed a model that examines the costs of producing green hydrogen using a solar and wind hybrid energy system in four locations in Chile, and also evaluates the emissions produced. The model uses local solar and wind generation data to determine the optimal capacity of the on-site solar PV and wind subsystems and the electrolyzer. The results indicate that green hydrogen can be produced at competitive prices, ranging from US$2.09/kg to US$3.28/kg, with very low CO2 emissions of 1.06–1.57 kg CO2e/kg H2. Additionally, the study suggests that using the hybrid electrolysis plant for hydrogen production is less polluting than the steam methane reforming process, which is currently the most widely used method. These findings can be used as a model for the development of emission laws and regulations related to clean technologies as well as a possible indicator for the pricing of green hydrogen.

The delayed effect of climatic conditions on pre‐fledging nestling haematocrit in a suboscine species in Patagonia

Haematocrit, the proportion of blood comprising erythrocytes, is often used as a proxy of individual condition. Nestling haematocrit is influenced by several factors but ambient temperature is generally agreed as a key driver. It is unclear which day(s) in embryonic or nestling development are most influential in determining pre‐fledgling haematocrit. This is important, because if we are able to identify what day(s) nestlings are physiologically most vulnerable to climatic conditions, this may inform future conservation management and help mitigate the effects. We investigated the effect of ambient temperature, precipitation, body size, brood size, age, food abundance and habitat on nestling haematocrit in Aphrastura spinicauda (thorn‐tailed rayaditos). We collected this data from two climatically different locations in Chile: northern Patagonia (Pucón) and Sub‐Antarctic Patagonia (Navarino Island), located ~ 1800 km further south. We aimed to identify the key drivers of nestling haematocrit and find when nestlings are physiologically most vulnerable to climatic conditions. We confirm that ambient temperature is the key driver of nestling haematocrit, with increasing ambient temperatures nestling haematocrit decreased. However, precipitation also affected haematocrit in the late incubation stage. At low and high precipitation, nestling haematocrit was low and is optimum in light rainfall. Our results show a delayed effect of ambient temperature and precipitation in late incubation and on the day of hatching which can determine pre‐fledgling haematocrit, which may cause lower post‐fledgling fitness. We found that climatic conditions on the day haematocrit was collected was not important in determining haematocrit. We found that haematocrit was higher in the sub‐Antarctic area and that higher temperatures and precipitation on the day of hatching will result in lower nestling haematocrit and poorer pre‐fledgling condition. As atmospheric temperatures rise, nestling fitness is at risk. This is a threat to many bird species, especially those in locations vulnerable to climate breakdown.

Millimeter/Submillimeter VLBI with a Next Generation Large Radio Telescope in the Atacama Desert

The proposed next generation Event Horizon Telescope (ngEHT) concept envisions the imaging of various astronomical sources on scales of microarcseconds in unprecedented detail with at least two orders of magnitude improvement in the image dynamic ranges by extending the Event Horizon Telescope (EHT). A key technical component of ngEHT is the utilization of large aperture telescopes to anchor the entire array, allowing the connection of less sensitive stations through highly sensitive fringe detections to form a dense network across the planet. Here, we introduce two projects for planned next generation large radio telescopes in the 2030s on the Chajnantor Plateau in the Atacama desert in northern Chile, the Large Submillimeter Telescope (LST) and the Atacama Large Aperture Submillimeter Telescope (AtLAST). Both are designed to have a 50-meter diameter and operate at the planned ngEHT frequency bands of 86, 230 and 345 GHz. A large aperture of 50 m that is co-located with two existing EHT stations, the Atacama Large Millimeter/Submillimeter Array (ALMA) and the Atacama Pathfinder Experiment (APEX) Telescope in the excellent observing site of the Chajnantor Plateau, will offer excellent capabilities for highly sensitive, multi-frequency, and time-agile millimeter very long baseline interferometry (VLBI) observations with accurate data calibration relevant to key science cases of ngEHT. In addition to ngEHT, its unique location in Chile will substantially improve angular resolutions of the planned Next Generation Very Large Array in North America or any future global millimeter VLBI arrays if combined. LST and AtLAST will be a key element enabling transformative science cases with next-generation millimeter/submillimeter VLBI arrays.

Soil Microbiome Influences on Seedling Establishment and Growth of Prosopis chilensis and Prosopis tamarugo from Northern Chile.

Prosopis chilensis and Prosopis tamarugo, two woody legumes adapted to the arid regions of Chile, have a declining distribution due to the lack of new seedling establishment. This study investigated the potential of both species to establish in soil collected from four locations in Chile, within and outside the species distribution, and to assess the role of the root-colonizing microbiome in seedling establishment and growth. Seedling survival, height, and water potential were measured to assess establishment success and growth. 16S and ITS2 amplicon sequencing was used to characterize the composition of microbial communities from the different soils and to assess the ability of both Prosopis species to recruit bacteria and fungi from the different soils. Both species were established on three of the four soils. P. tamarugo seedlings showed significantly higher survival in foreign soils and maintained significantly higher water potential in Mediterranean soils. Amplicon sequencing showed that the four soils harbored distinct microbial communities. Root-associated microbial composition indicated that P. chilensis preferentially recruited mycorrhizal fungal partners while P. tamarugo recruited abundant bacteria with known salt-protective functions. Our results suggest that a combination of edaphic properties and microbial soil legacy are potential factors mediating the Prosopis establishment success in different soils.

Human exposure to ochratoxin A and its natural occurrence in spices marketed in Chile (2016–2020): A case study of merkén

The potential ingestion of food products contaminated with ochratoxin A (OTA) is cause of concern for public health. Currently, several detection methods are available to detect OTA in singles spices but not in spice mixtures such as merkén. The present study modified, optimized, and validated a method for successful OTA quantification in merkén, paprika, and chili. A total of 321 merkén (n: 256), paprika (n: 39), and chili (n: 26) samples were collected from different retail locations in Chile over a 5-year period (2016–2020). OTA levels were determined by high performance liquid chromatography with fluorescence detection (HPLC-FLD). Validation parameters that included the limit of detection (LOD: 0.3 ng g−1), limit of quantification (LOQ: 1.0 ng g−1), linearity (0.9975), recovery in a fortified blank matrix (5 ng g−1: 81–105%), and relative standard deviation (RSD: 0.49–6.87%) were satisfactory. The presence of OTA in merkén, paprika, and chili samples was 66%, 59%, and 61%, respectively. Maximum OTA levels in merkén, paprika, and chili exceeded the limit established by national regulations of 5 ng g−1 by 77-fold (387.9 ng g−1), 59-fold (297 ng g−1), and 14-fold (71.6 ng g−1), respectively. The estimated daily intake (EDI) values were considerably higher in 2017 than 2020 (paprika ˃ chili ˃ merkén). The EDI values were also lower than the Benchmark dose level (BMDL10; 4730 ng kg−1 bw day) for non-neoplastic effects. Our study pinpointed the importance for continuously monitoring and regulating the OTA contamination in agricultural commodities such as spices. More investigations should be generated to modify the current regulation of OTA in spices.

Sero-Epidemiology of Pneumocystis Infection among Infants, Children, and Adults in Chile.

Previous serologic surveys show >80% of infants in Chile have anti-Pneumocystis antibodies by 2 years of age, but the seroepidemiology of Pneumocystis infection beyond infancy is unknown. We describe the sero-epidemiology in infants, children, and adults at different locations in Chile. Serum samples were prospectively obtained from 681 healthy adults (age ≥ 17 years) and 690 non-immunocompromised infants/children attending eight blood banks or outpatient clinics (2 in Santiago) in Chile. ELISA was used to measure serum IgM and IgG antibodies to Pneumocystis jirovecii major surface antigen (Msg) constructs MsgA and MsgC1. Serologic responses to Pneumocystis Msg showed a high frequency of reactivity, inferring infection. Among infants/children increasing age and the proportion with detectable IgM responses to MsgA, and IgG responses to MsgA, and MsgC1 were positively associated. Among adults there was almost universal seropositivity to one or more Pneumocystis Msg constructs. In infants and children rates of detectable IgM responses to MsgC1 and MsgA were greater than IgG responses. In Santiago, rates of seropositivity among infants/children were greater in clinics located in a more socio-economically deprived part of the city. In Chile, a serological response to Pneumocystis Msg constructs was common across ages regardless of geographical location and climatic conditions. Observed higher rates of IgM responses than IgG responses is consistent with concept of recent/ongoing exposure to Pneumocystis in children and adults. Higher rates of seropositivity in infants/children residing in more densely populated areas of Santiago infers crowding poses an increased risk of transmission.

Environmental-Community Psychology in the Disaster Research: The Importance of Social-Spatial Connections

The psychosocial literature in the context of socio-natural disasters mainly focuses on the psychological consequences of the affected people, while ignoring the psychosocial environmental factors. Here, we emphasize the relevance of community environmental psychology to analyze the subjective aspects of the relationship with the place and the community relations of the localities affected by disasters. Therefore, we propose a conceptual framework of the categories of community psychology and environmental psychology, which are related to the study of the social spatial connection in what we call socio-natural disasters. This view is illustrated by the results of a study using a hybrid approach that describes how people living in communities affected by earthquakes, tsunamis and volcanic eruptions in four locations in Chile. In a non-probabilistic convenience sample (n = 628), the responses to the scale of location attachment, location identity, residence satisfaction, community awareness and citizen participation were analyzed, as well as the narration of 17 focus groups (n = 117) on the meaning of public space construction. The conclusion is that the combination of environmental and community psychology expands the understanding of the elements of power and territorial disputes, and highlights the psychosocial defects in post disaster reconstruction solutions.

An annual energetic evaluation of booster and parallel refrigeration systems with R744 in food retail supermarkets. A Chilean perspective

In the supermarket refrigeration industry, the natural refrigerant R744 (CO2) has been designated as a long-term solution to mitigate HFC refrigerants' global warming. In this study, booster (BB) and parallel compression (BP) configurations were assessed through a detailed and novel energetic modelling, which includes a semi-empirical "four-parameter" for reciprocating and scroll compressor models and a one-zone model for the gas cooler, and a three zones model for the condenser. Model validation showed a mean deviation of 4.23% against reference values. The COP of the BP configuration was 14% higher than BB, for ambient temperatures between 0°C and 35°C. This study presents for the first time, the simulation of transcritical systems with R744 throughout out different locations in Chile. Simulation results of fourteen Chilean cities showed that the BP system allows reducing the annual energy consumption between 4% for very cold climates and 12% for desert regions. An economic analysis revealed that only in most desert and warm climates (Arica, Antofagasta and Santiago), the differential capital expenditures of the BP system over the BB were recovered within 20 years with the operational expenditure savings. For the rest of the evaluated cities, the BB system is a more profitable solution than BP. The study aims to support the introduction of refrigeration system with R744 in Chilean supermarkets.

Multi-objective optimisation of a solar district heating network with seasonal storage for conditions in cities of southern Chile

Rapid urban growth and enhanced quality of life have significantly increased the demands for indoor heating, especially in the developing world. In Chile, this demand is provided largely through low quality biomass which creates pollution problems. Due to the medium to high solar resource in most of Chile, solar thermal networks with seasonal thermal storage should be considered. In this paper, we assessed the use of solar energy with seasonal thermal energy storage to provide domestic heating through a heat network. For this, we performed a simulation-based multi-objective optimisation of the system’s design with cost and greenhouse gas emissions as objectives for two locations in Chile. Our results show that solar thermal networks are cost-competitive with conventional alternatives. Furthermore, the inclusion of seasonal thermal storage could improve the system performance decreasing the emissions by around 90% while increasing the LCOE by less than 20% compared with a conventional gas-heated network or resistive electric heating. We found that for specific system configurations and locations solar district heating with long term storage could be cost-competitive with burning firewood if externalities such as the social costs of local pollution were considered in the economic analysis.

Assessment of autonomous renewable energy system operability under extreme events and disasters

Autonomous, hybrid renewable energy systems (HRES) are increasingly being deployed in geographically challenging terrains, often lacking adequate resilience planning for natural disasters. An assessment framework is developed to evaluate sustainable HRES design for remote off-grid application, ensuring its operability under an extreme event, i.e. its ability to absorb the shock event and continue operating. Optimal HRES configurations are obtained for different extreme events, applying Pareto optimality with key criteria of minimising the number of black outs constrained by Net Present Cost (NPC). The framework is demonstrated for a remote location in Chile. Operability of an HRES under an extreme event is found to involve a trade-off between the investment decision to reduce the vulnerability of RET components and to enhance its energy storage. The optimised HRES is found to be cost-effective for resilience against seasonal events (for flooding and snowstorm the additional NPC is 4.6%, 7.4% respectively) but unsustainable for low probability-high impact events (for earthquakes the additional NPC of 20.5% largely from increase investment in storage capacity). The study also highlights the role of the dispatch strategy in enabling a micro hydro as a secondary storage component for both fulfilling the unmet loads and for charging batteries.

Usos de expresiones condicionales en diálogos argumentativos entre adultos mayores chilenos

What types of conditional structures do older adults express when they discuss dilemmatic contents, is the research question that motivated this work. To answer this question the importance of conditional and hypothetical thinking is first discussed; then we continue with the analysis of argumentative dialogues between elderly people in dyads and triads in terms of the driven premises of conditional structures, the frequency of conditional structures according to variables such as gender, education, age and geographical location in Chile, and an evaluation of the taxonomic uses of the conditionals found in their opinions. Among the findings it stands out that a large number of conditionals are advice, that another important percentage issued were counterfactual and deontic conditionals, the latter being characterized as practical conditionals that give instructions in an event-action scheme. The most important findings, however, are that the driven premises play a key role in the conditional statements of elderly people, and that the variable that generates a difference when comparing dyads and triads is geographic location, and not education, gender, or specific age interval within elderly.

Floral induction and dormancy behaviour in ‘Chilean white strawberry’ (Fragaria chiloensis (L.) Mill. subsp. chiloensis f. chiloensis)

The flowering process in Fragaria x ananassa has been widely studied, while the favourable environmental conditions for Fragaria chiloensis subsp. chiloensis f. chiloensis, the ‘'Chilean white strawberry', are not well understood. With the objective to study the floral induction and dormancy process in this species, several experiments were conducted from 2016 to 2019 using the ecotype ‘Contulmo’ for ‘Chilean white strawberry’ and the cv. ‘Camarosa’ for F. x ananassa, the latter as a reference genotype. Growth parameters and the differentiation state of apex were evaluated at two locations in Chile (33°38’ S and 38°45’ S) as well as in climate-controlled growth chamber (9 °C and 8 -h photoperiod). Additionally, the chilling requirement for dormancy release after different cold storage periods (2 °C in darkness) was determined in this species. This requirement was field-verified (38°45’ S) over two seasons. The ‘Chilean white strawberry’ showed continuous and reduced growth, without changes under different temperature and photoperiod conditions, with values significantly different from those of cv. ‘Camarosa’. In both locations, the floral and dormancy induction started late (June), occurred only in a part of the plants (20-30%) and them yielded a single inflorescence. In addition, it was determined that the ‘Chilean white strawberry’ require approximately 900-1,000 chilling units for dormancy release. Our results indicated that flowering is favoured only with low temperatures, lower than those necessary for many short-day genotypes. This characteristic, together with the late flowering, suggests that there is a vernalization requirement for this species. Temperature increase is probably the main factor involved in the current floral behaviour of ‘Chilean white strawberry’, however this can decreasing even more in a climate change context.

Assessment of time resolution impact on the modeling of a hybrid CSP-PV plant: A case of study in Chile

This study analyzes the time resolution impact on the modeling of a hybrid CSP-PV plant integrated with thermal storage and a battery bank for two locations in Chile. Daily and annual results were evaluated varying the time resolution from 1, 5, 10, 15, 30 to 60 min, as well as the capacity factor and LCOE. In this way, the CSP plant was the component most affected by the time resolution, followed by the battery dispatch, while the effect on PV production estimation was marginal. Control procedures of the receiver and power block were more realistically captured with time steps between 1 and 5 min, while with higher time steps, variability effects were neglected. Annual and techno-economic results indicate an overestimation of the total yearly production of the hybrid plant as the time step is increased, leading to an underestimation of the LCOE. Variations in the capacity factor and LCOE were around ±2–3% in both locations using the 5-minute time step (with respect to the 1-min results), and between ±4–6% using 10–60 min time steps. Different cases of study varying the dispatch strategy and components sizing were evaluated, showing that time resolution impact is lower for oversized PV configurations with respect to the CSP plant, and higher when the CSP plant is oversized with respect to the PV, regardless the dispatch strategy. Finally, this work provides some recommendations analyzing the advantages and drawbacks of implementing different time steps at each stage in the development of a hybrid solar power plant.

Climate change projections of temperature and precipitation in Chile based on statistical downscaling

General circulation models (GCMs) allow the analysis of potential changes in the climate system under different emissions scenarios. However, their spatial resolution is too coarse to produce useful climate information for impact/adaptation assessments. This is especially relevant for regions with complex orography and coastlines, such as in Chile. Downscaling techniques attempt to reduce the gap between global and regional/local scales; for instance, statistical downscaling methods establish empirical relationships between large-scale predictors and local predictands. Here, statistical downscaling was employed to generate climate change projections of daily maximum/minimum temperatures and precipitation in more than 400 locations in Chile using the analog method, which identifies the most similar or analog day based on similarities of large-scale patterns from a pool of historical records. A cross-validation framework was applied using different sets of potential predictors from the NCEP/NCAR reanalysis following the perfect prognosis approach. The best-performing set was used to downscale six different CMIP5 GCMs (forced by three representative concentration pathways, RCPs). As a result, minimum and maximum temperatures are projected to increase in the entire Chilean territory throughout all seasons. Specifically, the minimum (maximum) temperature is projected to increase by more than 2 °C (6 °C) under the RCP8.5 scenario in the austral winter by the end of the twenty-first century. Precipitation changes exhibit a larger spatial variability. By the end of the twenty-first century, a winter precipitation decrease exceeding 40% is projected under RCP8.5 in the central-southern zone, while an increase of over 60% is projected in the northern Andes.

Understanding solar resource variability: An in-depth analysis, using Chile as a case of study

Short-term solar radiation variability is a key parameter to understand the solar resource, as it is concerned with describing the dynamic characteristics of irradiance, that have significant transient effects in solar system performance. Worldwide installed solar capacity is consistently increasing and it can considerably affect the dynamics of electric systems. An understanding of resource dynamics and how it affects power forecasts will become paramount for appropriate handling of the solar resource. Chile showcases this scenario, as solar installed capacity is close to 10% of the nationwide total and energy curtailment is occurring mainly due to transmission restrictions. Although several metrics are available in the literature to assess solar resource variability, consensus needs to be stablished, as well as a common framework to evaluate results obtained through the different metrics. This work analyses 1-min resolution data for several years at eight locations in Chile to assess short-term solar radiation variability using 6 well-stablished metrics, compares the information provided by each one and develops correlations to compare results among them. Additionally, high-speed transient phenomena are analyzed and a new metric is defined to assess the solar resource with respect to its quality in static and dynamic terms. Finally, four day classification schemes are developed and evaluated, and results for Chile are shown in the context of its geography and climatological classification.

Comparative genomic analysis and molecular examination of the diversity of enterotoxigenic Escherichia coli isolates from Chile.

Enterotoxigenic Escherichia coli (ETEC) is one of the most common diarrheal pathogens in the low- and middle-income regions of the world, however a systematic examination of the genomic content of isolates from Chile has not yet been undertaken. Whole genome sequencing and comparative analysis of a collection of 125 ETEC isolates from three geographic locations in Chile, allowed the interrogation of phylogenomic groups, sequence types and genes specific to isolates from the different geographic locations. A total of 80.8% (101/125) of the ETEC isolates were identified in E. coli phylogroup A, 15.2% (19/125) in phylogroup B, and 4.0% (5/125) in phylogroup E. The over-representation of genomes in phylogroup A was significantly different from other global ETEC genomic studies. The Chilean ETEC isolates could be further subdivided into sub-clades similar to previously defined global ETEC reference lineages that had conserved multi-locus sequence types and toxin profiles. Comparison of the gene content of the Chilean ETEC identified genes that were unique based on geographic location within Chile, phylogenomic classifications or sequence type. Completion of a limited number of genomes provided insight into the ETEC plasmid content, which is conserved in some phylogenomic groups and not conserved in others. These findings suggest that the Chilean ETEC isolates contain unique virulence factor combinations and genomic content compared to global reference ETEC isolates.

Estimación de dietas del chungungo Lontra felina (Molina, 1782) en dos localidades de la región del Biobío, Chile

Lontra felina (Molina, 1782), locally in Chile referred to as chungungo, is a marine mustelid. Its distribution extends from Peru to Cape Horn. This species is considered endangered throughout its entire range of distribution. The main threats to its populations are illegal hunting, coastal pollution and exploitation of their food resources. It has been reported that chungungo feeds mainly on crustaceans, fish and shellfish. Previous studies have compared feeding ecology of L. felina in some locations of Chile, there are, however, no reports that determine and compare feeding ecology of L. felina in the Biobio Region. Noninvasive methods such as fecal analyses allow to determine some properties of the diet by analyses of indigested prey or their parts. The present study was conducted in two locations in the Biobio Region: Caleta Chome and San Vicente and a total of 131 fecal remains was collected (65 in Caleta Chome and 66 in San Vicente). Fecal specimens were sieved and the remains of undigested prey were identified and categorized as crustaceans, fish or shellfish and counted. Furthermore, the specimens were identified to the lowest possible taxonomic level using magnifying glass and identification keys available in literature as well as help of qualified lab personnel. In both locations low diversity of prey was found, the diet of chungungo in both locations consisted mainly of crustaceans, followed by fish and shellfish. Furthermore, the results indicate greater variability and diversity of prey consumed in Caleta Chome than in San Vicente.

Fixation Coefficient and Soil Residual Effect of Cadmium Application on Three Biannual Crop Rotations at Four Locations in Chile

Cadmium (Cd) is a metalloid present in agricultural soils and harmful for human health. A large part of the Cd entering into the soil can be fixed, while another portion can contribute to increasing availability indices of this element (residual effect). The present study evaluated Cd residual effect and Cd fixation derived from anthropic applications at four locations in Chile during two seasons. Three crop rotations were used, which included white lupine (Lupinus albus L.), narrow-leafed lupine (Lupinus angustifolius L.), and durum wheat (Triticum turgidum L. var. durum) as the first crop and durum wheat as the second crop. Results indicated that the anthropic application of Cd to the soil, in the three crop rotations and at the four locations under study, exhibited a low residual effect in the next season and null effect two seasons after its application. Among the three preceding crops of each rotation, the highest effect on Cd residuality in both seasons was achieved using both lupines, especially narrow-leafed lupine. The Cd fixation coefficient in the upper 0.2 m of soil in the three crop rotations and at the four locations was very high, and it was greater than 99.9% in all cases.