Investigation on Impact of Biodegradable Mulching Films on Soil Microbial Dynamics and Plant Root Metabolism: A Cross-Continental Mesocosm Study

• Applicants: Dr. Callum Banfield; Professorin Dr. Michaela Dippold
• Subject Area: Soil Sciences
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 551412358

Plastic mulching has become an integral part of sustainable agricultural practice. However, the environmental impacts associated with waste and microplastic pollution cannot be overlooked. These microplastics arise from the degradation of conventional plastic mulching, remaining in the environment to pose risks to ecosystems, contaminate soil and water bodies, and potentially enter the human food chain. Therefore, transitioning to biodegradable mulching films is considered a promising approach to mitigate these issues. However, the degradation products of these biodegradable plastics and their environmental impacts are not yet understood well. The ultimate goal of this project is to assess whether the degradation products from biodegradable mulch films affect the soil microbiome and its functions but also have implications on plant metabolism and exudation. To test this hypothesis, we will identify the compounds produced during the degradation of biodegradable mulch films using model soil systems and high-resolution mass spectroscopy and microbial inoculates from a range of representative Korean and German soils. The roles of film degradation products on processes in the plant-soil system will be studied in mesocosms to assess their effects on the soil microbial communities, their functions and maize plant root metabolites, all essential for nutrient cycling and soil fertility. Isotopically labeled biodegradable and conventional plastics (e.g., 13C-PHBV, 13C-PE) will be applied to trace the dynamics of plastic film degradation and the fate of their degradation compounds. Applying 13C-PHBV on soils with 14C-enriched microbial necromass (young soil organic matter) will allow to determine potential priming effects of biodegradable mulches on various pools of soil organic carbon. All studies will be performed on representative agricultural soils from both the Republic of Korea and Germany. Generating this comprehensive understanding will help us evaluate the overall impact of biodegradable mulch films on the various components of agro-ecosystems, providing fundamental insights on future development of sustainable agricultural practices.

• DFG Programme: Research Grants
• International Connection: South Korea
• Cooperation Partner: Professor Dr. Sunghwan Kim