Managing soil organic matter amendment and microbial community structure to enhance soil heating during solarization

管理土壤有机质改良剂和微生物群落结构以增强日晒期间的土壤加热

• 批准号: 1438694
• 负责人: Jean VanderGheynst
• 金额: $ 30万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1438694&HistoricalAwards=false
• 关键词: Managing; soil; organic; matter; amendment

1438694 (VanderGheynst). Soil fumigation with synthetic chemicals including methyl bromide, 1,3-dichloropropene, and chloropicrin, is an effective practice for controlling soil borne pests. However, it also results in accumulation of volatile organic compounds in the atmosphere, contributing to significant levels of air pollution. A promising alternative to toxicant-based soil fumigation involves combining organic soil amendments with soil solarization, in which soil is covered with a transparent plastic film, resulting in passive solar heating of the soil and inactivation of soilborne pathogens. Although combining soil amendments with solarization is very effective, it is not widely used because current practices require treatment during the time in which many crops are produced. The basis of this research is that solarization of amended soil would be utilized more widely if growers could adopt the practice without losing production. It is proposed that two lines of investigation might contribute to greater utilization of solarization: 1) exploration of techniques involving organic matter amendment that increase soil temperature, thereby reducing the time required for solarization and allowing treatment during off-peak production periods; and 2) elucidation of the contributions of microbial communities to organic matter decomposition and soil heating during solarization. Knowledge of the interaction between organic matter decomposition, community structure and organic acid accumulation will allow farmers to make more informed decisions on managing soil organic matter and microbial community amendment for enhanced solarization. Validation experiments will be part of demonstration activities directed towards UC Cooperative Extension educators so that the information gained from the project is disseminated and readily applied to benefit society at large. Also, the results from this research will become part of a 6th grade lesson and activity in the GK-12 program directed by the PI. This program pairs PhD students with 6th grade teachers to develop and deliver STEM curriculum related to renewable energy and environmental sustainability. The lesson and activity will incorporate the effects of short and long-wave radiation on thermal heating and pasteurization of soil. Once tested in classrooms with feedback from teachers, the lesson will be submitted to TeachEngineering.org. Student training will be highly interdisciplinary in engineering and biology.The overall approach to be pursued involves 1) experiments that examine how organic matter composition and microbial community inoculum can be tailored to facilitate heat generation associated with thermophilic fermentation in soil, 2) an in-depth characterization of microbial community dynamics, and 3) laboratory and field validation experiments. Soil heating studies will be conducted first using laboratory soil columns in temperature-controlled incubators. This will allow investigation conditions under which organic matter soil amendments stimulate aerobic microbial activity, and therefore metabolic heating. To elucidate the role of the microbial community on soil heating, inoculum composition and soil factors will be varied and the resulting community dynamics measured using high-throughput sequencing of extracted DNA. Soil amenability for supporting plant growth will be assessed using phytotoxicity assays. Field studies will be completed to confirm laboratory results and further investigate the effects of organic matter amendment and initial microbial community structure on soil heating and phytotoxicity of solarized soil. This research proposed will improve understanding of microbial activity dynamics and associated soil heating during soil solarization. Preliminary data indicate communities amended with organic matter enhance the rate of biological activity in the soil, however, little is known about the spatial and temporal changes in these communities and how they contribute to organic matter decomposition and production of organic acids that cause phytotoxicity. Next generation high-throughput sequencing will provide fundamental insight into the microbial community dynamics during soil solarization, and the role microbial communities play in soil heating during solarization.

1438694（VanderGheynst）。使用合成化学品（包括溴甲烷、1，3-二氯丙烯和氯化苦）进行土壤熏蒸是控制土传害虫的有效方法。然而，它也导致挥发性有机化合物在大气中积累，造成严重的空气污染。一个有希望的替代毒物土壤熏蒸的办法是将有机土壤添加剂与土壤日晒结合起来，即用透明塑料薄膜覆盖土壤，使土壤被动地受到太阳的加热，使土壤中的病原体失去活性。虽然土壤改良剂与日晒结合使用非常有效，但没有得到广泛使用，因为目前的做法需要在许多作物生产期间进行处理。本研究的基础是，如果种植者能够在不损失产量的情况下采用这种做法，改良土壤的日晒将得到更广泛的应用。有人建议，两条线的调查可能有助于更多地利用日晒：1）探索技术，涉及有机质的修正，提高土壤温度，从而减少日晒所需的时间，并允许在非高峰期生产期间的处理;和2）阐明微生物群落的贡献有机质分解和土壤加热日晒。了解有机物分解、群落结构和有机酸积累之间的相互作用，将使农民能够在管理土壤有机物和微生物群落改良以加强日晒方面作出更明智的决定。验证实验将是针对加州大学合作推广教育工作者的示范活动的一部分，以便传播从项目中获得的信息，并随时应用于造福整个社会。此外，这项研究的结果将成为PI指导的GK-12计划中六年级课程和活动的一部分。该计划将博士生与六年级教师配对，以开发和提供与可再生能源和环境可持续性相关的STEM课程。课程和活动将包括短波和长波辐射对土壤加热和巴氏杀菌的影响。一旦在课堂上进行了测试，并得到了教师的反馈，课程将提交给TeachEngineering.org。学生培训将是工程学和生物学的高度跨学科。要追求的整体方法包括：1）实验，研究如何调整有机质成分和微生物群落接种物，以促进土壤中嗜热发酵相关的产热，2）微生物群落动态的深入表征，以及3）实验室和现场验证实验。土壤加热研究将首先使用温度控制培养箱中的实验室土柱进行。这将允许调查条件下，有机物土壤改良剂刺激好氧微生物活动，因此代谢加热。为了阐明微生物群落对土壤加热的作用，接种物组成和土壤因素将有所不同，并使用提取的DNA的高通量测序测量所产生的群落动态。将使用植物毒性试验评估支持植物生长的土壤适应性。将完成实地研究，以确认实验室结果，并进一步调查有机质改良和初始微生物群落结构对土壤加热和日晒土壤植物毒性的影响。这项研究将提高对土壤日晒过程中微生物活动动态和相关土壤加热的理解。初步数据表明，社区与有机物质的修正提高了土壤中的生物活性的速度，但是，很少有人知道这些社区的空间和时间变化，以及它们如何有助于有机物质分解和产生的有机酸，导致植物毒性。下一代高通量测序将为土壤日晒过程中的微生物群落动态以及微生物群落在日晒过程中土壤加热中的作用提供基本见解。