Sandia National Laboratories

Plants capture atmospheric carbon dioxide (CO2) using photosynthesis, and transfer the carbon to the soil through their roots. Soil organic matter, which is primarily composed of carbon, is a key determinant of soil’s overall quality. Even though crop productivity has increased significantly over the past century, soil quality and levels of topsoil have declined during this period. Low levels of soil organic matter affect a plant’s productivity, leading to increased fertilizer and water use. Automated tools and methods to accelerate the process of measuring root and soil characteristics and the creation of advanced algorithms for analyzing data can accelerate the development of field crops with deeper and more extensive root systems. Crops with these root systems could increase the amount of carbon stored in soils, leading to improved soil structure, fertilizer use efficiency, water productivity, and crop yield, as well as reduced topsoil erosion. If deployed at scale, these improved crops could passively sequester significant quantities of CO2 from the atmosphere that otherwise cannot be economically captured.

Sandia National Laboratories will develop novel, field-deployable sensor technologies for monitoring soil, root, and plant systems. First, the team will develop microneedles similar and shape and function to hypodermic needles used in transdermal drug delivery and wearable sensors. The minimally invasive needles will be used to report on sugar concentrations and water stress in leaves, stems, and large roots in real-time. Continuously monitoring the sugar concentrations at multiple locations will be transformative in understanding whole plant carbon dynamics and the function of the vascular tissues that conduct sugars and other metabolic products downward from the leaves. The second key technology are gas chromatographs deployed in the soil and near plants in order to monitor volatile organic compounds (VOC). Plants synthesize and release volatile organic compounds both aboveground and belowground that act as chemical signals or in response to biotic stress (damage from insects, bacteria, etc.) or abiotic stress (such as drought, flooding, and extreme temperatures). VOCs modulate biomass uptake and the team hopes to better understand soil composition by measuring VOC transport. The team's integrated microsensor technologies will be deployed in arid environments in both natural and agricultural lands to characterize whole plant function in both environments. Applying these sensors to plants in arid environments could assist in re-greening arid ecosystems with new specially bred plants developed and selected to improve soil function with less water and nutrient requirements while depositing more soil carbon.