ECO-CBET: Foliar applied plant-activated nitrogen delivery agents for sustainable crop production.

农业对美国的经济、健康和国家安全至关重要。氮肥在农业中广泛使用，以确保消费者获得丰富和营养的食物供应，并为农民提供足够的经济回报。然而，目前的土壤氮肥输送途径和做法并不有效，作物使用的肥料负荷不到施用的50%。氮肥的低效使用继续在美国和世界范围内造成普遍和令人烦恼的环境问题，从地下水污染，有害藻华，富营养化到气体N2O污染物的排放，对水和空气质量产生负面影响。该项目的总体目标是开发一种以叶片为基础的施肥过程，该过程可以通过直接将氮和其他营养物质施用于叶片而不是土壤来有效地向作物输送氮和其他营养物质。为了实现这一目标，该项目的主要研究人员建议将氮肥封装到功能化的纳米颗粒载体中，将氮直接输送到植物中。这些载体将被设计为喷洒在植物叶片上。特殊的靶向配体将附着在N纳米粒子载体的表面上，并帮助引导它们到达植物中需要它们的位置。该项目的成功完成将通过开发新的基础知识来造福社会，这些知识可以用来指导更有效和可持续的氮肥输送过程的设计和部署。进一步的社会效益将通过学生教育和培训，包括指导5名博士研究生，1名博士后学者，约18名本科REU学生。农田土壤氮肥的施用造成了氮循环的严重失衡，造成了不可持续的环境后果。管理氮素循环是一项长期存在的重大工程挑战，只能通过彻底改变施用氮肥的方式来解决。该项目的总体目标是通过叶面施用高效定向和植物激活的氮素利用，改变氮素和其他营养物质向作物的输送。该项目的具体目标是：1)开发生物相容性载体颗粒（N载体），用于从农业副产品或地球丰富的矿物质中提取有效的氮输送；2)将植物生物识别分子嫁接到N载体上，使植物叶绿体能够靶向，提高N同化效率；3)建立分子和多尺度运输模型，预测n -载流子在叶片表面的转运和分布，以及与细胞内部表面的相互作用；4)量化氮素载体相对于土壤施氮肥料的生命周期、环境效益和风险。为了达到这些目标，该项目的主要研究人员建议汇集和整合来自不同领域/学科的想法和工具，包括纳米技术、界面工程、颗粒和多相运输、植物生物工程、环境工程和环境可持续性。该项目的成功完成有可能通过开发更有效和可持续的氮肥输送过程产生变革性影响，这可能会推进氮素循环有效和可持续管理的目标。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Agriculture is critical to the economy, health, and national security of the United States (U.S.). Nitrogen fertilizers are widely utilized in agriculture to ensure an abundant and nutritious food supply for consumers and adequate financial returns for farmers. However, current soil nitrogen (N) fertilizer delivery routes and practices are not efficient with crops using less than 50% of the applied fertilizer loads. This inefficient usage of N fertilizers continues to cause pervasive and vexing environmental problems in the U.S. and worldwide ranging from groundwater contamination, harmful algal blooms, eutrophication to the emission of gaseous N2O pollutants that negatively impact water and air quality. The overall goal of this project is to develop a foliar-based fertilizer delivery process that could efficiently deliver N and other nutrients to crops by applying the to the leaves directly rather than to the soil. To advance this goal, the Principal Investigators of this project propose to encapsulate N fertilizers into functionalized nanoparticle carriers that deliver the nitrogen directly into the plant. These carriers will be designed to be sprayed onto the plant leaves. Special targeting ligands will be attached onto the surfaces of the N nanoparticle carriers and help guide them to the locations in the plants where they are needed. The successful completion of this project will benefit society through the development of new fundamental knowledge that could be leveraged to guide the design and deployment of more efficient and sustainble N fertilizer delivery processes. Further benefits to society will be achieved through student education and training including the mentoring of five PhD students, one postdoctoral scholar, and ~18 undergraduate REU students.Soil-based nitrogen fertilization of cropland has created severe imbalances in the nitrogen (N) cycle with unsustainable environmental consequences. Managing the N cycle is a perennial engineering grand challenge that can only be met by a radical transformation in the way that N fertlizers are applied to crops. The overall goal of this project is to transform the delivery of N and other nutrients to crops by enabling foliar-based application with highly efficient targeted and plant-activated N utilization. Specific objectives of the project are to 1) Develop biocompatible carrier particles (N-carriers) for efficient N delivery that are derived from agricultural byproducts or earth-abundant minerals; 2) Graft plant-biorecognition molecules onto the N-carriers to enable the targeting of plant chloroplasts to increase N assimilation efficiency; 3) Develop molecular- and multi-scale transport models to predict N-carrier translocation and distribution through the leaf surface, and interactions with internal cell surfaces; and 4) Quantify the life cycle, environmental benefits, and risks of N-carriers relative to soil-applied N fertilizers. To achieve these objectives, the Principal Investigators of this project propose to converge and integrate ideas and tools from various fields/disciplines including nanotechnology, interfacial engineering, particulate and multi-phase transport, plant bioengineering, environmental engineering, and environmental sustainability. The successful completion of this project has the potential for transformative impact through the development of more efficient and sustainable N fertilizer delivery processes that could advance the goals of an efficient and sustainable management of the N cycle.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.