Set a target to reduce nitrogen loss and waste in farming
Scottish Government should commit to the Colombo Declaration target to halve nitrogen loss and waste by 2030 through a combination of more efficient use of bagged nitrogen, manures and slurries; an increase in the use of legumes, cover crops and intercropping; the promotion of organic farming, and the ending of bagged nitrogen use in high nature value farming as part of the new agricultural support framework. The revised Farm Advisory Service should have this as one of its key performance indicators.
Nitrous oxide 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.
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.
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
