PhD Position – Fate, environmental impact and ecotoxicity of biodegradable plastics in a plant-soil mulch agricultural system – PlasticUnderground MSCA Doctoral Network:
Project Background: Plastics are essential to meet the increasing population food demand, providing agriculture with key benefits: improving crop yields, decreasing pesticide use, and saving water consumption, among others. They are valued for their stability and durability. However, fields are littered with a variety of plastics unfeasible to be removed after use, particularly mulches.
These plastics are exposed to environmental agents that progressively break them into small fragments, which subsequently evolve to micro- and nano-plastics (MnP) and accumulate into the soil. The MnP may migrate across ecosystem compartments and enter the food chain, compromising environmental sustainability. Persistence of plastic fragments and MnP in the environment is increasing far more than expected and has already been reported to affect soil health and crop yield.
Biodegradable plastic mulches (BDM) have emerged as a promising alternative to alleviate agricultural plastic pollution. They are designed to naturally biodegrade into the agricultural soil to CO2, H2O, and biomass, leaving no significant fragments or residues. However, parallel to the expected benefits, some concerns are emerging. In the field, BDM fragments and their MnP, even if temporary, have similar physical attributes to equally alter soil properties and the plant-soil interaction as MnP produced from non-degradable mulches. Additionally, they release a diversity of chemicals (additives, monomers, polymers, biodegradation intermediates) whose effects require to be investigated.
Moreover, BDM have been limitedly used to date, with little track record yet of the BDM biodegradation efficiency, and of the biodegradable MnP potential accumulation on agroecosystem environments; remarkably, there is a gap in the knowledge of long-term effects the repeated BDM use may have on plants and on the soil ecosystem. Finally, since MnP and compounds released by BDM are susceptible to migrate across ecosystems, knowledge on their potential impact on other terrestrial and aquatic ecosystems is also required.
Overall, comprehensive understanding of the environmental impact and sustainability of continuous incorporation of BDM into the soil is urgently to be assessed. The project aims to contribute by providing knowledge to anticipate and prevent potential undesired effects of BDM on the environment, and especially on agricultural soils and on crops.
The researcher will be full member of the Agricultural Ecobiotechnology research team at the University of Lleida, with shared responsibilities in the project development, unveiling knowledge at the frontiers of science. The successful candidate will develop research strategies in the field, in the greenhouse and in the lab, identifying and determining the impacts biodegradable plastics, particularly mulches and the MnP produced thereof, on the agricultural soil environment, together with their effects on the global system sustainability.
Key responsibilities include:
- Determining the fate and effects of biodegradable and non-biodegradable mulches and their MnP on the agricultural soil, and their interaction with the soil environment: MnP production, residence time, transport, soil functions, and chemicals released during BDM biodegradation.
- Conducting mesocosm experiments to monitor the effects of MnP on cultivated plants’ growth and stress.
- Developing assays to assess for the ecotoxic potential of agricultural MnP on living organisms in the lab: in vitro cultured plants, microorganisms and ecotoxicity model organisms.
- As an overall result, the researcher will produce significant scientific knowledge, contribute to anticipate global effects of BDM use on the system sustainability, and guide towards environmentally-friendly BDM practices and formulations.
This position is offered as one of the 14 PhD 3-year positions funded by the Marie-Skłodowska-Curie Actions Doctoral Network (MSCA-DN) PlasticUnderground. PlasticUnderground DN is an international, multi-partner, inter-sectoral doctoral research-training network with the aim to prepare an international cohort of Doctoral Candidates in the development of solutions to the emerging plastic pollution crisis in soils and groundwater.
Given the evolving understanding of subsurface soil and groundwater ecosystems as long-term storage pools of micro- and nanoplastics, interdisciplinary capacity that can support and provide guidance for the management of these systems, as well as development of adequate technological, social behavioral and legislative solutions is urgently needed. This interdisciplinary DN will integrate comprehensive training opportunities in cutting edge technological innovations, regulatory and behavioral approaches across traditional disciplinary and sectoral boundaries.
The consortium comprises universities, research institutions and companies located in the UK, France, Spain, Serbia, Italy, Switzerland, Cyprus and Germany. The researcher is expected to travel internationally within the MSCA-DN, actively interacting with the members of the consortium; it will have the opportunity of training, gaining skills, and networking through short secondments in a selection of these universities, institutions and plastic industry companies.
- Prerequisites for the successful candidate to the MSCA-DN position Fate, environmental impact and ecotoxicity of biodegradable plastics in a plant-soil mulch agricultural system are:
- Hold a Bachelor and a Masters degree in agronomy, biology, biotechnology, environmental sciences or closely related fields.
- Excellent oral and written English.
- Not to be in possession of a doctoral degree
Valuable skills and experience:
- Research experience in disciplines within the subject, e.g. plant production, plant and soil analysis, plant tissue culture, ecotoxicity, soil health and biology, chemical analysis, agricultural plastic and micro/nanoplastics.
- Proven knowledge in disciplines secondarily related to the position, e.g. statistics, microscopy, image analysis, materials, sustainability.
- Author or coauthor of scientific papers in the subject area.
- Excellent communication and team working. Curiosity-driven self-motivation. Interpersonal skills. Independent and proactive working.
- Driving license.
- Spanish, oral and written.
There are no restrictions in nationality, but the selected candidate must comply with mobility rules of the PlasticUnderground DN: At the time of selection by the host organization, it must not have resided or carried out its main activity (work, studies, etc.) in Spain for more than 12 months in the three years immediately prior to recruitment.
This position is offered by Profs. Ana M. Pelacho and Lluís Martín-Closas, leading the Agricultural Ecobiotechnology research group at the University of Lleida (UdL). The UdL is a medium-size institution at the top of the Spanish universities in agricultural and food science and engineering, with especial dedication to crop and horticultural sciences and to plant biotechnology. The location is prominent in agriculture, complementing the excellent research environment at the UdL with an equally excellent productive surrounding.
Prof. Pelacho has a long track-record in plant science research and in supervising PhD researchers in plant sciences; she has also leaded the Agricultural and Food Science and Technology PhD program at the UdL, recognized with Excellence Award by the Spanish Government. Prof. Martin-Closas is a reputed researcher in sustainable agriculture and biodegradable agricultural products, particularly plastics, and holds a long-track record of valuable interactions with institutions and companies involved in agricultural plastic production and use.
The Agricultural Ecobiotechnology research group is focused on identifying and assessing high-technology novel agricultural products as substituting alternatives in intensive agriculture, to foster the agricultural system sustainability. The group maintains active research collaborations with other research groups at the UdL and with other national and foreign institutions. Together, we work within a multidisciplinary research focus, interlacing and producing knowledge in the areas of agricultural plant production, soils, chemistry and materials-technology, and environment.
The UdL and the research group will provide the successful candidate with full access to the research facilities to develop the PhD project, and will offer additional training in transversal skills. Moreover, the DN will offer the researcher ample opportunities for international and inter-sectorial interaction, advanced training and specialized courses.
How to submit application:
Prospective candidates are to send the application to Prof. A.M. Pelacho Email: email@example.com , until April 30th, 2023, including:
- Full CV
- Transcript of records
- Motivation Letter
- Name and contact details of two potential referees
- Short summary of research experience and merits gained related to the position.