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.
Project Innovation + Advantages:
Iowa State University (ISU) will develop new sensors that measure the amount of nitrogen in soils and plants multiple times per day throughout the growing season. Nitrogen fertilizer is the largest energy input to U.S. corn production. However, its use is inefficient due to a lack of low-cost, effective nitrogen sensors. Year-to-year variation in nitrogen mineralization, due to differences in soil water and temperature, creates tremendous uncertainty about the proper fertilizer input and can cause farmers to over-apply. As a result, nitrogen fertilizer is lost from croplands to the surrounding environment where it pollutes air and water resources. To address this problem, the team will develop a novel silicon microneedle in-plant nitrogen sensor and a microfluidic soil nitrogen sensor. The microscale needles can be inserted into multiple sites of the plant to provide frequent and accurate monitoring of nitrate uptake, and for the first time provide a view of plant nitrogen use as the plant and roots develop. The team will also develop an automated microfluidic sensor which will measure the amount of nitrate in soil by extracting very small amounts of solution from the soil. The microfludic technology on which soil sensors are based can be produced at low cost. The combination of these two sensors will allow for a deeper understanding of plant nitrogen use and how it correlates with nitrate levels in the soil. These new sensors will accelerate the effort to identify, select, and breed new crops with improved nitrogen use efficiency. And the project will help increase the energy efficiency of our agriculture systems while reducing input costs, greenhouse gas emissions, and nitrate pollution of aquatic ecosystems.
If successful, developments made under the ROOTS program will produce crops that will greatly increase carbon uptake in soil, helping to remove CO2 from the atmosphere, decrease nitrous oxide (N2O) emissions, and improve agricultural productivity.
America’s soils are a strategic asset critical to national food and energy security. Improving the quality of soil in America’s cropland will enable increased and more efficient production of feedstocks for food, feed, and fuel.
Increased organic matter in soil will help reduce fertilizer use, increase water productivity, reduce emissions of nitrous oxide, and passively sequester carbon dioxide from the atmosphere.
Healthy soil is foundational to the American economy and global trade. Increasing crop productivity will make American farmers more competitive and contribute to U.S. leadership in an emerging bio-economy.