Lipid biogeochemistry of paddy soil evolution

子项目P7研究了不同管理制度、不同作物和土壤相应基质中脂类的分子和同位素组成。脂质在化学分类上区分植物对土壤的输入，识别有助于土壤有机质的植物燃烧残留物（PAH），以及识别在不同发育阶段土壤中茁壮成长的微生物群落。由于水稻土的生物地球化学取决于所有这些控制因素，因此脂质组成与本项目中使用的其他方法具有很强的互补性。FOR995第一期对慈溪沿海地区氟维醇底物组成及其脂类生物地球化学进行了详细表征。通过研究不同基质类型及其对土壤脂质的相关影响，将对来自中国的Acrisols和来自印度尼西亚的Andosols、verisols和Acrisols/Ferralsols进行扩展和验证这些结果。在慈溪地区，海洋滩地转化为水稻土后，适应微生物群落的建立始于不到50年的时间，此后在长达2000年的时间里保持了相当稳定。假设印度尼西亚的热带环境对水稻管理的加速适应，将使用110年、45年和3年的水稻使用时间序列来验证土壤脂质的假设快速变化。印度尼西亚的管理做法预计将强制延长稻田缺氧时间，影响微生物活动和土壤有机质保存。综合中国慈溪和红壤地区以及爪哇和苏门答腊地区水稻土脂质地球化学的环境差异，获得东南亚水稻土演化的总体视角。

Subproject P7 investigates the molecular and isotopic composition of lipids in soils of different management systems, of different crop plants and of the corresponding substrates on which the soils evolved. Lipids chemotaxonomically differentiate the plant input into soil, identify plant combustion residues (PAH) that contribute to soil organic matter, and identify the microbial communities that thrive in soils of variable developmental stage. As the biogeochemistry of paddy soils depends on all of these control factors, lipid compositions are highly complementary to other approaches utilized in this project. The Fluvisol substrate composition in the coastal Cixi area and its lipid biogeochemistry has been characterized in detail in the first phase of FOR995. Extension and validation of these results via the study of different substrate types and associated effect on soil lipids will be conducted on Acrisols from China and Andosols, Vertisols and Acrisols/Ferralsols from Indonesia. Establishment of adapted microbial communities after conversion of marine tidal flats to paddy soils commenced in less than 50 years and thereafter remained rather stable for up to 2000 years in the Cixi area. An accelerated adaption to paddy management is hypothesized for the tropical environment in Indonesia, where a chronosequence with 110, 45 and 3 years of paddy use will be used to verify the postulated rapid changes in soil lipids. The management practices in Indonesia are expected to enforce longer periods of anoxia in paddies, affecting microbial activity and soil organic matter preservation. Environmental differences in paddy soil lipid geochemistry for the Cixi and Red Earth area in China, as well as for Java and Sumatera will be synthesized to obtain a general perspective of paddy soil evolution in Southeast Asia.