Episode 95 Rebroadcast

The production of food, crops, and livestock, such as chicken eggs and beef, has seen a significant increase in productivity since the Second World War. Use of fossil fuels has also increased significantly in agriculture using diesel for tractors, and natural gas for dryers and the manufacturing of pesticides and other fertilizers by way of examples. The transportation of these goods and commodities is also fueled by fossil fuels. Of importance is that nitrogen ammonia base fertilizers in soil are transformed by native microbes, releasing nitrous oxide in the air, a potent greenhouse gas that can significantly contribute to climate change. Dr. Tenuta research focuses on improving the retention of soil and not emitting nitrogen oxide. By reducing nitrogen losses farmers can become more efficient in using nitrogen to produce crops. By improving the retention of soil and reducing nitrogen emissions in agriculture, farmers can thus reduce their greenhouse gas footprint and contribute to a more sustainable future as they feed the world. Food production involves significant energy use and GHG emissions. Microbes in the soil transform nitrogen fertilizer, releasing N2O, a potent greenhouse gas (300 times more potent than CO2). While the amount of N2O emitted from fields is relatively small, its potency makes it a significant environmental concern. N2O loss is also an indicator of other nitrogen losses from the soil, which can be substantial (10-30% of applied nitrogen). The "Four R's" (Right Rate, Right Source, Right Time, Right Place) are a framework for optimizing fertilizer use and minimizing nitrogen losses. This involves considering: (1) Rate: Applying the correct amount of nitrogen based on crop needs and soil conditions; (2) Source: Choosing the appropriate type of nitrogen fertilizer; (3) Time: Applying fertilizer at the optimal time (e.g., spring rather than fall, split applications); and (4) Place: Placing fertilizer in the soil rather than on the surface to reduce atmospheric losses. Even organic fertilizers like manure, compost, and fish bycatch can contribute to N2O emissions. The composting process itself also releases N2O. However, growing nitrogen-fixing crops like soybeans, peas, and lentils does not produce N2O. The discussion touches on the possibility of producing "green ammonia" using renewable electricity (e.g., solar and hydropower), air, and water. This could reduce the carbon footprint of fertilizer production and provide farmers with more stable pricing. The possibility of using autonomous robots for precise, micro-dosed nitrogen application and weed control is discussed. While challenges remain (e.g., navigating closed crop canopies), such technology is considered within reach. The speakers discuss the reluctance of governments to impose GHG taxes or regulations on farmers, highlighting the economic challenges farmers already face. They note that the fertilizer industry is actively involved in efforts to reduce nitrogen losses. The interview emphasize the complexity of reducing agricultural GHG emissions, noting that there are no easy solutions.