FOR 995:  Biogeochemistry of Paddy Soil Evolution

• Subject Area: Agriculture, Forestry and Veterinary Medicine
• Term: from 2008 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 55047603

For more than fifty percent of the world's population rice is the most important food. Lowland rice is grown on so-called paddy soils under waterlogged conditions during most of their growth. This leads to environmental problems not only on the national, but also on the international scale, because wetland rice fields contribute about 10-25 percent to global CH4 production. In spite of a lot of recent studies dealing with chemical and physical properties of paddy soils, there is still a lack of knowledge concerning the biogeochemistry of major ecological processes involved in the formation of paddy soils.
A suite of samples selected from the chronosequence in the Zhejiang province, one of the earliest and major rice production areas, will be used to identify relevant processes. This includes the formation and cycling of soil organic matter as well as coupled processes like nitrogen cycling, turnover of dissolved organic matter and development of mineral compounds during paddy soil evolution. The microbial community as the key driver of all these processes will promote the redox- and soil moisture-depending changes in soil minerals and soil organic matter and in turn interacts with these changes. Investigation of lipid biomarkers and radiocarbon dating are useful tools for the quantification of turnover times and will be jointly studied by an interdisciplinary research team.
China is one of the earliest and major rice production countries, with areas ranging from several years up to several 1000 years of rice cultivation. Today, China produces about 30 percent of the total world rice grain. Increasing population and increasing commercial relevance emphasises the importance of international and interdisciplinary research on ecological functioning and sustainable land use. The Research Unit will closely collaborate with senior scientists of the Chinese Academy of Sciences and will, therefore, strongly contribute to the Sino-German environmental research.

• DFG Programme: Research Units
• International Connection: China, Indonesia, Netherlands

Projects

• 14C AMS as a tracer to study carbon dynamics resulting from paddy management under different climatic conditions in different soil types (Applicant Grootes, Ph.D., Pieter M. )
• Changes in the mineral composition of paddy soils upon redox cycles (Applicants Fiedler, Sabine ;  Jahn, Reinhold )
• Coordination of the Research Unit and development of a conceptual model of paddy soil evolution (Applicant Kögel-Knabner, Ingrid )
• Dissolved organic matter driven changes in minerals and organic-mineral interactions during paddy soil development (Applicants Fiedler, Sabine ;  Jahn, Reinhold )
• Dynamics of microbial communities involved in carbon and nitrogen turnover during paddy soil evolution in relation to different soil types (Applicant Schloter, Michael )
• Lipid biogeochemistry of paddy soil evolution (Applicant Schwark, Lorenz )
• Organic matter stabilisation during paddy soil development depending on soil type (Applicant Kögel-Knabner, Ingrid )
• Production and stabilization of dissolved organic matter in paddy soils depending on redox conditions (Applicant Kalbitz, Karsten )
• Sequestration of microbial, aged and pyrogenic N during paddy soil development (Applicant Amelung, Wulf )

• Spokesperson: Professorin Dr. Ingrid Kögel-Knabner