The web-based calculator helps farmers manage cover crops and nitrogen fertilizer with more precision, resulting in fewer farm emissions.
Growing among the remains of harvested corn stalks, these green shoots of rye take up excess nutrients in the soil. When the new crop is planted in the spring, the rye will be killed and left to release the nutrients back to the soil for crop growth.
Image Credit: Edwin Remsberg
Brian Needelman, an associate professor in the Department of Environmental Science and Technology at the University of Maryland, has been awarded a $1.2 million grant from the U.S. Department of Agriculture's Natural Resources Conservation Service. The grant will support the development of a web-based tool that will help farmers make informed decisions about fertilizer use and estimate greenhouse gas emissions.
Nitrogen from excess fertilizer and plant material left in fields can pollute waterways and become a significant contributor to greenhouse gas emissions, particularly nitrous oxide, which is released when bacteria digest nitrogen. To combat this issue, farmers can use cover crops, which they plant in the off season, to help absorb some of the excess nitrogen. The plants store the nitrogen in their tissues all winter, and release it back into the ground in the spring when farmers kill off the cover crop and plant their cash crop. This reduces the amount of commercial fertilizer farmers need to apply.
Reducing fertilizer use and limiting greenhouse gas emissions can make significant environmental impacts while also saving farmers money. However, determining how much nitrogen a cover crop takes up and how much nitrous oxide is emitted can be difficult due to various factors such as climate, weather, and soil conditions.
Needelman and his colleagues aim to address this challenge by integrating satellite imagery of farm fields with location-specific data on soil composition, rainfall, temperature, and other climate factors to more precisely predict the real-time conditions of cover crops throughout a farm field. This information is then used to calculate the nitrogen available for cash crops in different parts of the field, so a farmer can make real-time decisions about how much nitrogen to apply in different areas, and more precisely estimate greenhouse gas emissions. The tool is called the Cover Crop Nitrogen Calculator (CC-NCALC), and it will be available online through the Department of Agriculture.
The project also aims to pilot an approach that involves installing video cameras on tractors to capture the growth of cover crops at a very high resolution, which can be fed into the computer models and provide highly-precise recommendations for nitrogen application in individual crop rows.
Over the course of the three-year project, Needelman and his colleagues will develop mathematical models to combine the satellite data with real-time field data and test the decision tool with farmers across the country. The improved web-based nitrogen decision management tool will be presented to the USDA by the end of the project for use by farmers across most of the U.S.
"We're excited to work with farmers across the country to develop a tool that can help them make better decisions about their use of fertilizer and their impact on the environment," Needelman said. "This project has the potential to significantly reduce the environmental impact of farming while improving the efficiency and productivity of the industry."
