Humberto Aponte ● Investigador Postdoctoral

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]We propose a three-stage study to explore the roles of BCRNF on NUE, wheat productivity, and nutritional grain quality. In Stage 1, we will assay the effect of BCRNFs on N-dynamics and chemical soil properties through soil incubations performed under controlled conditions for 90 days. We will measure N-losses periodically through volatilization of NH3 and NO2. Additionally, we will quantify potentially mineralizable nitrogen (PMN), changes in the C:N ratio, and changes in pH and soil nutrient content during nine sampling dates. In Stage 2, two independent experiments will be conducted to evaluate the interaction among BCRNFs with soil and its effect on the morphological, physiological, and biochemical plant adaptive strategies related to NUE. In Experiment 1, wheat will be harvested at the pre-anthesis growth stage, and plant growth parameters and N concentration in tissues will be used to determine N uptake efficiency (NUPE). Additionally, it will measure plant adaptative strategies related to N-uptake, such as root architecture, exudation of organic acids by roots, and changes in enzymatic and microbial activities in the soil. In Experiment 2, wheat plants will be harvested at the maturity stage to evaluate the relationship between grain yield and N concentration to determine N utilization efficiency (NUTE). Plant adaptive strategies related to NUTE will also be assessed, including N-translocation and remobilization, CO2 assimilation rate (A), stomal conductance (gs), photosynthesis per unit of N, PNUE. In addition, the leaf response to the fluorescence and stay green trait will also be performed. The amount of nitrogen in grain derived from the fertilizer (Ndff) will be calculated using the δ15N values obtained from grains. In Stage 3, the effect of BCRNFs on wheat productivity and nutritional quality will be evaluated in field conditions. The trials will be conducted over two agricultural seasons, and the impact of BCRNFs on soil and plant samples will be assessed at three different stages: anthesis, soft dough grain, and hard dough grain. During these stages, the chemical properties of the soil, as well as microbial and enzymatic activities, will be evaluated. Photosynthetic parameters such as A, gs, Ci, E, Fo, Fm, and QY will be quantified. The plant height, harvest index, and yield components will be assessed at the end of each growing season. Grain quality indicators like protein content, gluten levels, and sedimentation rate will also be measured. Finally, the amount of nitrogen in grain derived from the fertilizer (Ndff) will be calculated using the δ15N values obtained from grains. This proposal focused on understanding the interconnections among soil, N-fertilizer, and plant physiology, using wheat as a model crop. The primary aim is to boost N management strategies in agriculture, ensuring a balance between productivity and sustainability. The initiative seeks to create a technological solution to enhance NUE, reduce environmental impact, and ensure global food security.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Los microplásticos son partículas de plástico con un tamaño entre 0.1 μm y 5 mm, los cuales han recibido una amplia atención debido a sus posibles efectos sobre los organismos vivos, la contaminación de los ecosistemas, la baja tasa de reciclaje, su fácil transporte y su interacción con contaminantes orgánicos e inorgánicos. Los microplásticos son considerados contaminantes emergentes, pues, sus efectos sobre los organismos aún no han sido totalmente descritos. Sin embargo, se ha demostrado que los diversos aditivos que poseen los plásticos (por ejemplo, bisfenoles, ftalatos, irganox) afectan negativamente a diversos organismos, con potenciales efectos adversos para la salud humana. Por otra parte, a medida que los microplásticos sufren el proceso de envejecimiento o degradación por efecto de las condiciones ambientales, estos poseen una mayor área superficial y reactividad, lo que promueve su interacción con otros contaminantes inorgánicos (por ejemplo, metales pesados) y orgánicos (por ejemplo, hidrocarburos policíclicos aromáticos). Por lo tanto, los microplásticos poseen diversos riesgos para los organismos que no se conocen a profundidad, lo que requiere un mayor esfuerzo investigativo a nivel mundial. Si bien la problemática de la contaminación por microplásticos es de conocimiento público, su estudio se ha enfocado en los ecosistemas marinos, específicamente en el agua, arena de playa en la línea costera y diversos organismos, con poco esfuerzo de muestreo en otras matrices ambientales como los suelos, aguas continentales y la atmósfera. Esta última es de gran importancia ya que, debido al bajo tamaño y densidad del microplástico, este puede ser resuspendido en la columna de aire, siendo fácilmente transportado desde el suelo a la atmósfera y siendo expuestos a los organismos vivos. Es por esto que el material particulado proveniente de eventos de deposición húmeda y seca es considerado como un gran aporte de microplásticos en sistemas terrestres y acuáticos, lo que es de gran relevancia cuando se considera la interacción del microplástico con elementos potencialmente tóxicos como metales u otras moléculas orgánicas. Por lo tanto, la literatura reciente en el área de los microplásticos muestra un incremento en las investigaciones del microplástico atmosférico, pues, es este el que finalmente es inhalado directamente por los seres vivos. En Chile, a pesar de ser el país en América Latina que más genera plásticos de un solo uso, y que además posee comunas ubicadas entre las 10 ciudades más contaminadas de dicha región, los estudios sobre microplásticos son escasos. Cabe destacar que esta categorización está asociada a la calidad del aire, por lo que la presencia del material particulado es un problema significativo. En este contexto, no existen estudios publicados a nivel nacional que evalúen el microplástico atmosférico, por lo que tampoco existe evidencia sobre la interacción entre dicho plástico y otros contaminantes. Esto aplica para la Región de O’Higgins, la cual, al ser una región minera y agrícola, es esperable que presente microplásticos en el material particulado, con la posible interacción con elementos potencialmente tóxicos, especialmente en los asentamientos con mayor densidad poblacional y desarrollo. Por lo tanto, la presente propuesta busca evaluar la ocurrencia y características de microplásticos presentes en el material particulado en una zona urbana y periurbana de la Región de O’Higgins, considerando su interacción con elementos potencialmente tóxicos, la estacionalidad y los eventos de deposición húmeda y seca. Para esto se integrarán disciplinas cómo el estudio de la meteorología, la química analítica y la contaminación ambiental. Se colectará y analizará el material particulado de forma mensual cada dos meses durante un año, esto para detectar, cuantificar e identificar los microplásticos presentes debido a eventos de deposición húmeda y seca. Se instalarán colectores pasivos de material particulado en las inmediaciones de la Universidad de O’Higgins (Campus Rancagua, Campus Colchagua, Estación Experimental Choapinos, Chapetón). Las partículas de microplásticos serán analizadas mediante espectroscopia FT-IR/ATR y/o con detector FPA. Posterior a la identificación de los tipos de polímeros, las partículas se analizarán con el microscopio de barrido para evaluar la presencia de metales en la superficie del microplástico. Además, se realizará una extracción con solventes para el análisis de hidrocarburos policíclicos aromáticos y bisfenoles policlorados presentes en el microplástico mediante un GC-MS. Finalmente, se realizarán diversos modelos para detectar los mejores predictores meteorológicos y poblacionales para predecir la deposición del microplástico en el material particulado por efecto de la deposición húmeda y seca. Se espera someter un artículo científico con los resultados de este proyecto para el último año de ejecución, y además se busca que este proyecto fortalezca el estudio de los microplásticos en la Universidad de O’Higgins, siendo soporte significativo para futuras postulaciones en equipamiento especializado e investigaciones de gran novedad internacional. Por último, este proyecto sentará las bases para una futura investigación que evalúe de forma directa e indirecta los efectos del microplástico en la salud humana de las comunidades de la Región de O’Higgins.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Proyecto de colaboración internacional entre España, Chile, Argentina y Ecuador. El proyecto aborda la recuperación de suelos degradados a través del uso de enmiendas orgánicas.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Microplastics (MPs) are plastic particles that range in size from 0.1 μm to 5 mm. They have received widespread attention in the global environmental science community due to their potential effects on living organisms, ecosystem pollution, low recycling rate, and interaction with organic and inorganic contaminants. Although much research has been focused on MPs in aquatic ecosystems, terrestrial ecosystems have been largely overlooked. Consequently, there is still scarce knowledge on the sources and occurrence of MPs in soils. After being deposited in soil, MPs undergo an aging process that involves the breakdown of their polymeric chains, which promotes the interaction between MPs and organic and inorganic contaminants. This process further increases the toxicity of MPs when they sorb pollutants from the environment, which can be transported to water bodies and living organisms. However, research regarding the aging of MPs and their toxicity is needed since previous studies do not consider realistic soil conditions. Additionally, interactions between MPs and pollutants have been primarily studied for conventional MPs, with scarce research on such topics for degradable MPs, especially concerning interactions with metal(loid)s. In general, the interaction of degradable MPs with other contaminants and their further toxicity have been overlooked. MPs have been shown to negatively affect some physical, chemical, and biological soil properties. However, results varied between studies, which have been associated with the type and shape of MPs, soil aggregate structure, porosity, water and oxygen availability, among others. More research is needed to confirm such relationships in soils. Previous studies have been mainly performed in Europe and Asia, with scarce research in Latin America. In Chile, only one study has been conducted on MPs in soils at field conditions, with other two studies regarding the effect of MPs and metals on soil biochemical properties under controlled environments. Therefore, considerable efforts should be taken to study MPs in Chilean soils. Thus, this study aims to address these gaps by considering some realistic approaches that are missing from current research on MPs. Specifically, this research will: 1) assess MPs in soils from different land uses and examine their association with soil properties; 2) evaluate degradable MPs; 3) study the ageing and adsorption capability of different MPs to metal(loid)s in soils; and 4) investigate the interactive effect of MPs and metal(loid)s under realistic conditions (including a real dose of MPs and metal(loid)s, temperature fluctuations, and soils from different land use types). By taking these steps, this study will provide novel insights into the occurrence of MPs in Chilean soils and shed light on the dynamics of soil microbial communities in the presence of MPs and metal(loid)s. Based on the above, the proposed research aims to evaluate the effect of different types of MPs and their interaction with metal(loid)s on the soil community structure and functionality from different land use types under realistic conditions. The hypothesis is that MPs will negatively affect soil microbiome structure and functionality due to changes in soil physicochemical properties, which will be moderated by changes in the type, doses, ageing of MPs and their interactions with metal(loid)s in soil from different land type uses. This proposal will be conducted in the O’Higgins Region (VI) of Chile. Firstly, in Phase 1, six localities from different land use types will be selected: an urban wetland, agricultural field, and sclerophyll forest. Soil samples will be taken to quantify and characterize the types of MPs in soil. Secondly, in Phase 2, the evaluation of different types of aging of MPs (conventional and degradable) on chemical characteristics of such particles will be performed, which is based on the ability of MPs as carriers of metal(loid)s. With information and soils obtained from Phase 1, a realistic experimental approach will be performed in the Phase 3. These include the evaluation of aged MPs (degradable and non-degradable) on soil physicochemical and biochemical properties, and the study of degradable and non-degradable aged MPs with metal(loid)s on the functionality, structure, and co-occurrence patterns of soil microbial communities. These phases are designed to be performed over three years. This is the first study focused on the evaluation the effect of MPs and metal(loid)s on microbial communities of soils from different land use types in Chile.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Promover una alianza nacional e internacional con el fin de fortalecer la red de colaboración en el sistema suelo–planta para la generación sustentable e inocua de alimentos, mediante la aplicación de estrategias biotecnológicas y académicas, con foco en el cambio climático y prevención de contaminantes emergentes, como las micotoxinas.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Sistema Articulado de Investigación en Cambio Climático y Sustentabilidad de Zonas Costeras de Chile CUECH/RISUE RED21992[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]

[vc_section el_class="container mx-auto align-items-center circle--pattern" css=".vc_custom_1648956589196{padding-top: 3rem !important;}"][vc_row el_class="pb-5"][vc_column][vc_wp_custommenu nav_menu="6"][uoh_breadcrumb_component automatic_breadcrumb="true"][uoh_title_component title_dropdown="big" title_decorator="true"]{{title}}[/uoh_title_component][vc_column_text css=""]Mining activities have discharged large amounts of wastes or mine tailings to the environment, which represent an important environmental issue. Mine tailings are mainly characterised by poor physicochemical properties that limit the plant establishment and development. The most negative property in these mine wastes is the high content of metals and metalloids [metal(loid)s], which are often highly toxic due to acid pH that increases metal(loid) bioavailability. This negatively affects living organisms and ecological functioning since soil microorganisms are pioneer colonisers that mediate the plant establishment. Also, mine tailings are usually deposited in abandoned locations of large land cover; from where, due to their physical characteristics, they can be transported by air and water, affecting communities and the environment in surrounding areas. There are several industrial strategies focused on the physical and chemical management of mine tailings, but these are highly expensive and occasionally not effective. These strategies have not been suitable techniques to reduce negative impacts of mine tailings on the environment. In this context, biological approaches, such as phytoremediation, have been proposed as more appropriate strategies due to low cost, easy applicability, and promising results. Nevertheless, most of the studies focused on phytoremediation of mine tailings, especially Chilean studies, have been performed in laboratory conditions. Although these studies show promising conclusions, in many cases unsuccessful results are obtained at field conditions, mainly due to laboratory experiments do not consider the dynamic field variability and potential ecological interactions. Based on the above, the proposed research aims to evaluate the effect of the initial addition of organic-mineral amendments and the bioaugmentation of microbial communities with “core microbiome” from the root-zone of native herbaceous on the growth and development of native plants and microbial communities at copper mine tailings. We hypothesise that the growth and development of native plants in mine tailings will be promoted by the improvement of physicochemical properties of modified mine tailings (incipient technosols) through the addition of organic-mineral amendments, and the bioaugmentation of microbial communities with “core microbiome” involved in plant fitness obtained from copper mine tailings and surrounding soils. To evaluate the mentioned hypothesis, this study will be executed in three phases: 1) Initial field characterisation: this will be done for mine tailings and soils under sclerophyllous forest; 2) Collection and recruitment of “core microbiome”: this will study the composition, function, and interactions of “core microbiome” obtained from the root-zone of native herbaceous established on mine tailings and soils under sclerophyllous forest, by which a laboratory-scale assay it is needed to produce inoculum of such ecological units (cores); 3) Restoration field experiment: this consists on the field establishment of native herbaceous species by bioaugmentation with “core microbiome” from root-zone mine tailings and root-zone soil on incipient technosols produced by the addition of organic-mineral amendments on mine tailings. These phases are designed to be performed in three years. This study can provide insights of the promotion of ecological process and natural resilience on microbial communities of mine tailings and surroundings, which can allow the initial plant establishment a development for later possible plant recruitment from the native sclerophyllous forest. This would also evaluate whether mine tailings can be in situ managed instead of been totally removed, which implies high costs and workflow to enterprises. Additionally, this study would represent the first approach of the evaluation of the biological functioning and composition of microbial communities from root-zone mine tailings in Chile, from its current state to the subsequent restoration process.[/vc_column_text][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649209804184{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5"][vc_row el_class="container mx-auto align-items-center p-md-0 pt-5"][vc_column el_class="p-0"][/vc_column][/vc_row][/vc_section][vc_section css=".vc_custom_1649210787516{background-color: #f6faff !important;}" el_class="p-md-0 pt-md-5 pb-md-5"][vc_row el_class="container mx-auto align-items-center"][vc_column][/vc_column][/vc_row][/vc_section]