Performing Department
(N/A)
Non Technical Summary
The nitrogen cycle is fundamentally important to ecosystem health, crop productivity, food security, biosphere-atmosphere exchange, air quality, and climate change. The processes that drive nitrogen transformations in soil are influenced by environmental conditions that can exhibit large variability on millimeter and hour scales.These same variations can lead to hot spots and moments of intense gas production, impacting air quality and climate change. The current state of knowledge of the nitrogen cycle is limited by a lack of empirical data at spatiotemporal scales necessary to challenge biogeochemical models. Improving this understanding will better inform ecological and agricultural decision-making aimed at preserving natural resources, battling climate change, and increasing crop productivity, thereby helping USDA achieve its Strategic Goals 1 and 2.Aerodyne Research willdevelop, demonstrate, and commercialize a novel sampling and detection system that can measure key intermediates of the nitrogen cycle - nitrate, nitrite, and hydroxylamine -on mm-scales and with hourly time resolution. Current methods aimed at measuring these compounds are labor-intensive, destructive, insensitive, or lack the necessary resolution.The automated Aerodyne system will connectan array of small soil water probes to a fast, sensitive gas analyzer, enabling real-time, hands-offsubsurface mapping of these chemicals. The resulting technology will provide deep new insights into the nitrogen cycle in soil and its role in crop productivity, ecology, soil pollution, air pollution, and climate change. This broad range of impacts will also give it substantial commericial potential, accessing markets in agronomy, atmospheric sciences, subsurface monitoring, and ecology.
Animal Health Component
20%
Research Effort Categories
Basic
20%
Applied
20%
Developmental
60%
Goals / Objectives
The nitrogen cycle is a foundational process in the critical zone that enables Earth's soils to sustain plant and animal life. Although many of the transformations that make up the nitrogen cycle occur in aerobic and anaerobic regions of the vadose zone, they are intimately connected to the atmosphere and biosphere.Soil is both a source and a sink of atmospheric dinitrogen (N2) as well as a source of nitrous oxide (N2O), nitric oxide (NO), and other compounds that play key roles in local air quality and global climate change.Understanding the mechanisms that drive subsurface nitrogen transformations is important for improving agricultural productivity and unraveling the contributions of natural and agricultural soil microbiomes to air pollution and climate change. Controlling the depositions, transformations, and losses of nitrogen in soil is a primary goal in efforts to maximize crop yield, reduce production costs, and minimize the environmental impact of agricultural activities.While great strides have been made toward understanding these transformations, there remain fundamental mechanistic questions that are presently difficult to address due to the heterogeneous and fluctuating nature of real-world soil environments. New, nondestructive experimental tools are needed to interrogate these processes on spatial and temporal scales that are relevant to the nitrogen cycling microbiome.The major goals of this project are to i) combine novel subsurface solute extraction with spectroscopic gas-phase detection to enable new in situ observations of key subsurface nitrogen cycling pathways with high spatial and temporal resolution; and ii) develop a commercially viable sampling and detection system based upon these technical efforts.The central concept behind this Phase II SBIR project is to couple a microdialysis-based soil water extraction methodwith a high precision infrared trace gas analyzer for detection of nitrate, nitrite, and hydroxylamine with micromolar sensitivity. Achievingthese major goals requires successful completion of the following objectives:Interfacing mL liquid sample to the TILDAS: further modifying the TILDAS absorption cell design and choosing materials to best operate with liquid samples. Phase I results suggest that the major challenge for quantitative measurement of liquid injections is analyte losses to absorption cell surfaces in the infrared gas analyzer. In Phase II, we will pursue a multi-pronged approach to limit surface losses including modifying the cell body design, heating the cell, and changing cell surfaces to limit losses.Flow design and sample preparation: designing and building the sample multiplexing system and optimizing automated sample preparation.In Phase II we will design and assemble an on-line, automated, multiplexed microdialysis (MD) flow system for integration with a TILDAS. This consists of two components: the multiplexing system and sample preparation. The multiplexing system will utilize multiselector and trapping valves to extract microliter sample volumes from microdialysis probes. Development of a commercializable hardware and software package will allow for automated, hands off sampling from an array of microdialysis probes. The sample preparation component consists of testing and automating simple chemical reaction (acidfication) steps to detect nitrate and nitrite with high sensitivity.Optimizing spectroscopy and building a TILDAS. Hydroxylamine, nitric acid and nitrous acid will be simultaneously detected with a dual-laser TILDAS instrument. One laser will be used to measure NH2OH and the second laser will measure both HNO3 and HONO. We will purchase and install both lasers at appropriate wavelengths for optimal detection of all three species and characterize spectroscopic parameters in the hydroxylamine spectral region.Given the linestrengths used in the simulation, we expect a sensitivity of~30 nM for nitrite and ~260 nM for nitrate.Testing, refining, and challenging the system.This objective will be achieved by i) assemblingthe multiplexed MD system in the laboratory, ii) optimizing operational parameters and best practices, iii) determiningmeasurement conditions under which this measurement approach is challenged, and implementing a simple calibration setup.Laboratory demonstration. This objective is aimed at demonstrating the system in a real world laboraotry environment to address and interesting scientific challenge.The microdialysis-based sampling technique will be used to expand mechanistic understanding of soil N cycling in post-fire environments and determine how novel pyrophilous or "fire-loving" microbiomes influence soil N transformations and emissions. These laboratory studies will be in collaboration with Prof. Peter Homyak at the University of California, Riverside.Commercialization.The efforts described here will allow us to develop a commerical system that will enable subsurface sampling of important nitrogen species relevant to the nitrogen cycle.The system will have substantial commercial potential due to its ability to quantify important chemical species in soil with high sensitivity and selectivity at unprecedented spatial and temporal scales. We will achieve this objective with the support of our commercialization assistance partner, Dawnbreaker.
Project Methods
The Phase II SBIR project will primarily consist of laboratory research and development, disseminating that information, and commercializing the resulting technology.Laboratory research and development key milestones:Development of a sampling system that quantitatively recovers key nitrogen solutes in soil water. This will be evaluated by making solution standards and measuring the recovery of the solutes from those solution, with and without soil.Chemical treatment of a the retrieved microliter soil water sample. This will be evaluated by acidifying a sample that has been extracted from a solution standard and measuring the resulting concentration of the reaction products.Automating the sampling and treatment system. After development of a hardware and software interface for automated use, it will be evaluated by setting up mock laboratory experiments using known standards, and allowing the system to operate in a "hands-off" mode for several days. This will allow us to identify any potential issues an end user may have.Coupling to a TILDAS analyzer. This will be evaluated by measuring sample losses during injection and absorption cell losses, and iteratively modifying injection and detection designs to minimize those losses. Sensitivity will be evaluated with thegoal of achieving micromolar-scale detection for nitrate, nitrite, and hydroxylamine.Refining and challenging the system. The compiled system will be challenged in the laboratory to determine ways in which it can fail, allowing us to refine the system and operating practices. Success will be evaluated during demonstration of the system in a laboratory setting (UC Riverside) with graduate students and post-doctoral scientists operating the system.These efforts will utilize standard laboratory techniques: data recording in digital notebooks storage in a central data server, and analysis in the Igor numerical analysis program.Dissemination:The results of the Phase II efforts will be disseminated in publications, presentations, and in informational brochures. Success will be evaluated in terms engagement with the research community (number of publications and presentations, patents, and requests for more information).Commercialization:Commercialization methods will include operating exhibition booths at scientific conferences and by directly interfacing with potential customers. The commercial success will be evaluated by number of quote requests, instrument sales, and collaborative research revenue directly resulting from development of this technology.