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）。与合成化学物质（包括甲基溴化物，1,3-二氯丙烯和氯吡普林）在内的合成化学物质的土壤熏蒸是一种有效控制土壤虫害的实践。然而，这也导致大气中挥发性有机化合物的积累，导致大量空气污染。一种有前途的基于有毒物质的土壤熏蒸的有希望的替代方法是将有机土壤修正案与土壤阳光结合在一起，其中土壤被透明的塑料膜覆盖，从而导致土壤的被动太阳加热和土壤生存的病原体失活。尽管将土壤修正案与阳光化相结合非常有效，但它并没有被广泛使用，因为当前的做法需要在生产许多农作物的时间内进行治疗。这项研究的基础是，如果种植者可以在不失去生产的情况下采用这种做法，则将更广泛地利用修订的土壤的阳光化。有人提出，两条调查可能有助于更大程度地利用阳光化：1）探索涉及有机物修正案的技术，从而增加了土壤温度，从而减少了在非高峰生产期间允许治疗所需的时间； 2）阐明微生物群落对有机物分解和土壤加热过程中的贡献。了解有机物分解，社区结构和有机酸积累之间的相互作用将使农民能够就管理土壤有机物和微生物社区修正案做出更明智的决定，以增强阳光化。验证实验将成为针对UC合作扩展教育者的演示活动的一部分，以便将项目获得的信息传播并随时应用于整个社会。同样，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。该课程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有关的STEM课程。该课程和活动将结合短波辐射对土壤热加热和巴氏杀菌的影响。一旦在教师的反馈中在教室中进行测试，该课将提交给thengengineering.org。 学生培训在工程和生物学方面将是高度跨学科的。涉及的总体方法涉及1）实验，这些实验可以量身定制有机物组成和微生物群落的接种物，以促进与土壤中嗜热的热量发酵相关的热量，2）2）一个微生物社区动态的深入表征，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的孵化器中的实验室土壤柱进行。这将允许调查有机物土壤修正案刺激有氧微生物活性，从而代谢加热的条件。为了阐明微生物群落在土壤加热方面的作用，接种物组成和土壤因子将有所不同，并使用提取的DNA的高通量测序测量所得的社区动态。土壤敏感性将使用植物毒性测定法评估植物生长。现场研究将完成以确认实验室结果，并进一步研究有机物修正案和初始微生物群落结构对土壤加热和植物毒性的影响。这项研究提出的将提高对土壤腐蚀过程中微生物活性动力学和相关土壤加热的理解。初步数据表明，通过有机物进行修订的社区增强了土壤中的生物活性率，但是，对于这些群落的空间和时间变化以及它们如何对有机物的分解和产生引起植物毒性的有机酸的产生，知之甚少。下一代的高通量测序将提供对土壤阳性过程中微生物群落动态的基本见解，以及微生物群落在阳光过程中的土壤加热中的作用。