In a new study published in September 2020, an international research team led by the University of Basel, Switzerland, with the participation of the European Commission's Joint Research Centre, France's ISPA, Bordeaux Sciences Agro, the UK's Centre for Ecology and Hydrology and the Kangwon National University in South Korea, investigated global phosphorus losses in soil. The researchers combined high-resolution global data on the phosphorus content of soils with local soil erosion rates.
On this basis, they established that almost all regions are suffering from negative phosphorus balances that, if left unremedied, will have a serious and detrimental impact on agriculture and food crop yields.
As a finite and non-renewable natural resource, there have already been high-level discussions on 'peak' phosphorous and the threat it poses to sustainable human development. While phosphorus mineral deposits in small regions of the Western Sahara and Morocco were discovered recently, it has not altered the fact of the predicted phosphorus shortage, it has only provided further grounds for the shortage based on political and technical restraints, rather than just physical scarcity.
In the European Commission's Communication on the Farm to Fork Strategy, the excess of nutrients in the environment due to overuse and poor absorption by plants is highlighted as a key target, with a proposed 20% reduction on the use of fertilisers in the EU by 2030.
However, the emphasis on both nitrogen and phosphorus in the environment fails to delineate the fundamental difference in the environmental effects of both substances. Because the phosphorus environmental cycle does not have an atmospheric component, it is not a contributor to greenhouse gas emissions. Meanwhile, its eutrophication effects on algae and other plant life in water sources represents a devastating waste of a crucial yet limited resource.
With the European Parliament still deliberating its position on the Farm to Fork Strategy, it is essential that the intended integrated nutrient management action plan to be developed between the Commission and the Member States encompasses cross-sectoral goals on nutrients which are not only contained in the Strategy, but also in the new EU Circular Economy Action Plan and the Horizon Europe research and innovation program.
While the Circular Economy Action Plan states that an integrated nutrient management plan should ensure more sustainable methods of applying nutrients, it also indicates that the directives on wastewater treatment and sewage should also be assessed by the Commission to explore natural means of removing nutrients from the environment. Furthermore, the Horizon Europe orientation document states that a comprehensive EU policy on balancing nutrient cycles is not yet well developed, and that further research and innovation is needed with regards to nutrient flows.
Therefore, efficient nutrient use must be emphasized in the final resolutions on the Farm to Fork Strategy to be issued by the European Parliament, as well as the delineation of measures to address phosphate waste in the environment when compared to other nutrient inputs.
Further studies are also needed to analyse the lifecycles of different nutrients so that separate management routes can be applied. Finally, the development and implementation of nutrient recycling is essential, and the Parliament must support new technologies so that phosphorus can be recovered from the environment and become circular, rather than scarce.
Figure 1. Soil P pools and depletion due to erosion in Africa, Europe and North America.
AD = Atmospheric Deposition. CF = Chemical Fertilizer. OM = Organic P management = sum of manure and residue input minus plant uptake. Arrows indicate fluxes (positive: net input to soils, negative: depletion of soils). Non-plant P = non-plant available P. Inorganic and organic P give plant available fractions. Soil Plost: sum of P fractions lost from soil via erosion with relative errors. No/with chemical = P balance with and without chemical fertilizer.
(Christine Alewell et al., 2020)
Alewell, C., Ringeval, B., Ballabio, C., Robinson, D.A., Panagos, P., Borrelli, P. 2020. Global phosphorus shortage will be aggravated by soil erosion. Nat Commun 11, 4546.
A Farm to Fork Strategy for a fair, healthy and environmentally-friendly food system, Brussels, 20.5.2020 COM(2020) 381 final
Circular Economy Action Plan For a Cleaner and More Competitive Europe, 11.03.2020, COM(2020) 98 final
Orientations towards the first Strategic Plan for Horizon Europe, October 2019