Real-Time Mapping of Hydroxylamine and Other Trace Gases in Soil

Project SummaryUnderstanding and controlling the transformations of nitrogen in soil is a fundamental toolof modern agriculture.The nitrogen cycle is an important set of microbial processes that canincrease plant-available nutrients but can also lead to losses in the form of greenhouse gasemissions and leaching.Identifying and using these processes to sustainably improve soil healthincrease crop yield and minimize ecological impact requires a foundational understanding of theirmechanisms and drivers.However the inherent spatial heterogeneity and temporal variability ofthe soil environment challenges current experimental tools that are aimed at exploring subsurfacenitrogen cycling.New approaches are needed that can interrogate nitrogen pathways in situ andwith high spatial and temporal fidelity.The goal of this project is to develop and commercializea measurement platform capable of identifying and mapping subsurface nitrogen cyclingprocesses in real time.The overall system will add new knowledge and complement existingtools that provide a wealth of information on sparse spatiotemporal scales.The proposed projectwill address the USDA research priority to develop new technologies for measuring "soil nutrientcontent" and "microbial functional activity related to nutrient cycling" (Topic 8.4 Priority 2) andto "monitor air quality and reduce air pollution stemming from agricultural enterprises" (Topic8.4 Priority 3).The proposed technology will combine recently developed diffusive soil gas probes with anew spectroscopic platform capable of detecting hydroxylamine and the isotopomers of nitrousoxide both of which are messengers of subsurface nitrogen pathways.This novel measurementcapability will allow identification of specific nitrogen cycling processes.During Phase I thespectroscopic analyzer will be developed and built; the sampling approach will be investigated andoptimized to minimize artifacts and losses; the combined system will be tested in the laboratoryusing abiotic and real-world soils; and a prototype will be designed for construction in Phase II.The proposed research and development will yield a detection system that enables real- time in situ mapping of subsurface nitrogen pathways by measuring hydroxylamine and othertrace gases.It will be marketed to the soil science research community which is in need of newtools to improve the understanding of nutrient cycling in real-world soils.This market is alreadylarge and growing due to the continual need for more agricultural productivity food security andthe increasing importance of biofuel production.