Set a target to for nitrous oxide reductions in farming
Scottish Government should set a target of a 25% nitrous oxide reduction from farming by 2032 through a combination of more efficient use of bagged nitrogen, manures and slurries, an increase in the use of legumes, cover crops and intercropping, and the reduction of nitrogen use in the large areas of land being farmed for nature.
Nitrous oxide is an important greenhouse gas, and is about 300 times more powerful than carbon dioxide. Most nitrous oxide emissions from agriculture come from the interaction between reactive nitrogen and soil, with some coming from the way we store and handle animal manure and slurry. Currently more than half of bagged nitrogen is used on grassland. Better use of clover and more diverse leys can reduce the need for added nitrogen while improving soil and animal health.
Nutrient budgeting, yield mapping, crop monitoring, controlled release fertilisers and variable rate application all contribute to nitrogen use efficiency. Further uptake of these measures are expected to result in a cumulative reduction of 50% in nitrous oxide emissions by 2045.
A Nitrogen Levy, as proposed in the SCCS ‘Finance Climate Justice’ report, could add an extra incentive to reduce nitrogen use.263
There are other benefits. Better management of nitrogen in farming also leads to reduced ammonia emissions, which means less local ozone and fine particle air pollution, and less reactive nitrogen deposited with rain onto natural systems.264
For further information:
- Farming for 1.5: from here to 2045, 2021, https://www.farming1point5.org/reports
- Soil Carbon and Land Use in Scotland, ClimateXchange, 2018, https://www.climatexchange.org.uk/media/3046/soil-carbon-and-land-use-in-scotland.pdf
Financing Climate Justice – fiscal measures for climate action in a time of crisis, p.68, Stop Climate Chaos Scotland, 2022, https://www. stopclimatechaos.scot/wp-content/uploads/2022/09/FinancingClimateJustice_Report_ONLINE.pdf
Effects of net zero policies and climate change on air quality, the Royal Society, 2021, https://royalsociety.org/topics-policy/projects/airquality- climate-change/