Climate change affects everything. While agriculture, if it continues with ‘business as usual’, is likely to be one of the largest emitters of greenhouse gases by 2050, it is also likely to be the system impacted most by climate change.
Accounting as it does for 75% of the UK’s land area and 11% of UK emissions, agriculture will play a critical role in helping nature’s recovery and adaptation to climate change. At the same time, agricultural land must continue to produce enough food, fuel and fibre to meet society’s needs, while contributing to other objectives such as water management. We need a holistic approach to shift agricultural practices for climate, nature and people.
RSPB commissioned research to investigate which agricultural solutions offer synergy between climate and nature, and where there is a risk of conflict. This assessment is built on an extensive review of the literature, as well as consultations with RSPB specialists.
There are several stand-out interventions which deliver the most for both climate and nature:
Support nature-based solutions to climate change
The organic soils found in peatlands store vast amounts of carbon. Many UK peatlands are currently net sources of greenhouse gases to the atmosphere due to degradation: only 1% of England’s deep peat is considered undamaged. Drainage, cultivation, overgrazing and burning can all lead to release of carbon. Restoring peat by halting and reversing processes that lead to degradation (for example, through grip blocking or re-wetting) are quick, ‘no-regrets’ interventions with benefits for climate, nature and people.
Permanent grasslands have higher stocks of soil carbon than do croplands – it is best to avoid conversion in the first place, but reverting improved grassland or arable land to semi-natural grassland can increase carbon storage. This can be an entire land area, or in spots such as buffer strips and field margins, field corners and hedgerows. When croplands are converted into grassland, sequestration will not go on forever, but these grasslands will hold vast stocks of carbon.
Protecting coastal habitats also increases carbon stocks. Much of UK coastal habitat has been lost as a result of development and land conversion for agriculture. In some circumstances agriculture must cease; in others a change of agricultural system to protect coastal habitats from impacts such as fertiliser run-off, or to restore positive management such as low-intensity grazing will be beneficial.
Transition to climate friendly farming systems
Research suggests that some, but not all, food produced from organic systems in England and Wales has a greenhouse gas benefit compared to conventional farming, when considering the true greenhouse gas cost of production and transport of inorganic fertiliser in conventional systems. Where feasible, mixed farming can reduce emissions by re-integrating crop and livestock production and improving the efficiency of land and resource use, by enhanced nutrient cycling and improving soil health.
Adding trees to the landscape can increase carbon sequestration through both the carbon incorporated into the trees themselves and the soil. In the right circumstances and design, agroforestry can provide similar levels of timber as forestry, and similar levels of food production as pasture, and trees can provide a food crop. Integrating trees into arable systems can increase soil fertility and enhance natural pest control.
Less is more livestock
Clearly, reducing the density of ruminant livestock will reduce emissions because there are fewer animals present emitting greenhouse gases. However, intensity of grazing can also influence the carbon balances of the grasslands themselves. In some conditions, light grazing stimulates root and vegetative growth, increasing productivity and sequestration rates, whereas overgrazing can damage soils.
Nutrient management
Making efficient use of and minimising mineral fertilisers, incorporating applied manure or slurry into soil, and reducing the exposure of organic fertilisers to the air can significantly reduce emissions of ammonia and methane.
Arable
Spring-sown crops have lower nitrogen requirements than winter-sown crops and may therefore lead to reduced emissions of nitrous oxide from soil and of carbon dioxide from fertiliser production and transport. Similarly, any crops which are more efficient in nutrient uptake will have a positive impact.
Including leguminous crops like beans or peas in rotations provides biological nitrogen fixation. Legume crops do not require nitrogen fertilisers and can also have a fertilising effect on the crop that comes after them in the rotation. Using cover crops to avoid bare ground over winter reduces nitrate leaching and may reduce emissions of nitrous oxide and enhance soil carbon sequestration. Leguminous cover crops can also provide so-called ‘green manure’ if ploughed into the soil.
Recommendations
Farmers should be able to adopt these practices now – but many are constrained by a lack of funds or expertise. Policy and legislation must prioritise this immediately, through:
For a full copy of the report, see the attachment below or please contact mair.floydbosley@rspb.org.uk.
Image credits:
Wildflower meadow, Forest Farm, Wales. Image RSPB rspb-images.com
Avon heath country park, Dorset, White Park cattle which help improve heath and woodland. Image David Kjaer Rspb-images.com
Wild bird cover crop next to wheat, Bowhouse Farm, Fife, Scotland. Image Ian Francis rspb-images.com
First year arable reversion, Manor Farm, Sussex. Image Andy Hay rspb-images.com
If we do nothing, we shall suffer severe losses. Adaptation is required, and it is required immediately.
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