IFOAM EU at COP21 - Industrial farming leads to soil degradation, not to soil carbon sequestration
According to the IFOAM EU, soil carbon sequestration should not divert attention from the need to reduce agriculture emissions and to transform the agri-food industrial system.
In the official UN accounting system, the agriculture sector represents 10% of emissions on paper. But some estimations attribute to it a much higher share of GHG emissions worldwide. If the emissions linked to the production of synthetic fertilisers, and the indirect impacts, such as deforestation linked to feed or oil production, are taken into account, the share rises to 33% of emissions. Most direct emissions are due to nitrous oxide, linked to synthetic fertiliser production and use, and to methane, due to livestock.
Living and healthy soils are a cornerstone of organic farming. Protecting soils from erosion and degradation is crucial, and soil carbon sequestration is important and has many positive side effects.
But should soil carbon sequestration be the priority of action in agriculture? Is soil carbon sequestration going to be a silver bullet? Soil carbon sequestration should not be considered prominent approach to mitigate agricultural GHG emissions, and it should not distract from what should remain the priority: moving away from agriculture practices and food & farming systems that significantly contribute to GHG emissions and to soil degradation. A business as usual approach in agriculture will not in any case achieve any soil carbon increase.
According to IFOAM EU, the following key aspects and principles should always be considered when talking about soil carbon sequestration:
- Managing soil carbon is very important and has a lot of positive side effects (improving soil fertility, soil structure, water holding capacity). Increasing average soil organic matter levels (and therefore carbon) has to happen anyway – even without taking into account any mitigation potential – as we need to reverse soil degradation seen within many arable and horticultural soils in Europe. Soil organic content is important for yields, yield stability and to reduce the likelihood of localised flooding due to increase surface run-off and excessive river siltation (and therefore for farm resilience to extreme weather). Adaptation efforts should recognise the key role of agroecological agriculture practices in maintaining and regenerating soils.
- Organic farming sequester more carbon than conventional farming, and has the potential to sequester even more. A 2012 global meta-analysis found that organic farms store the equivalent of 2018.5 Kgs CO2 per hectare per year in soils – 3.5 metric tonnes more carbon per hectare on average than non-organic farms (1). A 2013 meta-analysis of 24 organic/non-organic comparison trials in Mediterranean climates found that the organic systems sequestered 3559.9 kg of CO2/ha/yr. The data came from comparison trials from Mediterranean climates in Europe, the USA and Australia and if extrapolated globally would sequester 17.4 gigatonnes (Gt) of CO2 (2).
- IFOAM EU believes that all farmers should be looking to organic techniques to increase soil carbon levels - so the use of longer rotations, catch-crops, cover crops, green manures, more legumes, more perennials and bringing more livestock and their manure back onto arable farms (e.g. renting out access to grass leys). A business as usual approach utilises little of these soil building techniques. Furthermore, farming practices which store more carbon also tend to reduce greenhouse gas emissions, which are otherwise ongoing – for example in the manufacture of artificial fertilisers.
- Industrial farming leads to soil degradation, not to soil carbon sequestration. In many EU countries where intensive agriculture is practiced, soil carbon levels are actually declining in arable and horticultural farmland. So intensive agriculture here is therefore not a net sink and a business as usual model means ongoing soil degradation, soil carbon losses and a potential to decrease future yields, on top of huge amounts of greenhouse gas emissions and a totally lost opportunity for carbon sequestration. A study and a review of a 50 years US agricultural trial found that the use of synthetic nitrogen fertiliser resulted in an average loss of around 10,000 kg of soil carbon per hectare and the loss of all crop residues. The higher the application of synthetic nitrogen fertilizer, the greater the amount of soil carbon lost as CO2 (3) (4).
- There is a limit to the amount of carbon that can be stored in soil. Even if it would be true that soil carbon sequestration can offset part of human emissions now, there will be a point when carbon sequestration stops but emissions continue if we stay with business as usual. However the greatest soil carbon gains can be achieved in the first 20 or so years of changing how soils are managed, and it is the next 20 years that we need to cut emissions the most. The potential for soil carbon sequestration should be carefully assessed, not overstated.
- Soil carbon sequestration is not permanent. It takes a long time to sequester carbon in soil, but it can very quickly be lost again if farm management changes. This means one needs to ensure that farmers remain committed to keep the carbon in the soil when potential is reached. Public support may be needed even if it doesn’t generate additional carbon sequestration. Farmers are under a huge amount of financial pressure to make short-term decisions which harm soils in the long-term but increase their profits in the short-term. But unhealthy soils costs the public in terms of lost carbon sequestration potential, increased local flood risks and in the long-term – decreased food security. It is time that to recognise that soils are a public good and that they do need the same environmental protection as water and air. This means not only is public support needed for farmers to change how they manage soils in the long-term – we need regulatory action at the EU level.
- Any action in the land sector should be done in addition to action in other sectors, and land should not be used as an offset mechanism i.e. soils should not be used to offset continued industrial or agricultural emissions, and should not be done instead of actual emissions reduction. Incentivising better soils is a crucial thing, but not if it ultimately gets added into GHG reduction targets. Treating land/ soils as a sink needs to be done very carefully due to the risk of land grabs, displacement of food security, non-permanence of soil carbon, weakening ambition in reducing industrial emissions, and difficulty and costs in monitoring, reporting and verification (MRV) of soil carbon. The Paris climate deal must therefore ensure food security is protected and not threatened.
Therefore, according to IFOAM EU, soil carbon sequestration should be seen as a co-benefit of adaptation, not as a mitigation tool.
(1) A. Gattinger, A. Mueller, M. Haeni, C. Skinner, A. Fliessbach, N. Buchmann, P. Mäder, M. Stolze, P. Smith, N. El-Hage Scialabba, and U. Niggli (2012) Enhanced top soil carbon stocks under organic farming. Proceedings of the National Academy of Sciences.
(2) Aguileraa E, Lassalettab L, Gattinger A and Gimenoe S (2013) Managing soil carbon for climate change mitigation and adaptation in Mediterranean cropping systems: a meta-analysis, Agriculture, Ecosystems and Environment 168 (2013) 25–36
(3) Khan S A, Mulvaney R L, Ellsworth TR and Boast (2007), C. W. The Myth of Nitrogen Fertilization for Soil Carbon Sequestration. Journal of Environmental Quality. 2007 Oct 24; 36(6):1821-1832
(4) Mulvaney RL, Khan SA and Ellsworth TR (2009) Synthetic Nitrogen Fertilizers Deplete Soil Nitrogen: A Global Dilemma for Sustainable Cereal Production, Journal of Environmental Quality 38:2295-2314 (2009): 10.2134/jeq2008.0527, American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America 677 S. Segoe Rd., Madison, WI 53711 USA
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