Optical Probe for Rapid In-Situ Survey of Soil Moisture and Carbon

An important goal of current biological research is being able to capture and adequately model the complex processes that mediate subsurface-microbe-plant-atmosphere interactions and responses- In particular, computing hardware has advanced to the point where high resolution biogeochemical conditions can be coupled to genomics-informed reactive transport models to study and visualize three-dimensional soil and plant processes- In addition, complex models capture the dynamics of gas, water, and nutrient exchange- However, high spatial and temporal resolution datasets are required to validate the accuracy of and drive downstream calculations of these complex models- Sensors are needed that can collect the requisite data through minimally-invasive means- The overall objective of the Phase I project is to demonstrate the feasibility of an easily-deployed optical probe for rapid evaluation of the vertical distribution of soil moisture and organic carbon content in the top several meters of soil- The soil probe is based on a fiber-coupled spectrometer employing a programmable light source and high speed detectors- The feasibility of the sensor will be evaluated through radiometric modeling, engineering design, and laboratory experiments to characterize the relevant physical phenomenology-