Beyond the disruption to Ukraine's food exports, the war is jeopardising the country's long-term ability to remain the 'breadbasket of Europe', because its soils are gradually losing vital crop nutrients.
That is the warning issued by researchers from the UK, Ukraine and the Netherlands who say more nitrogen, phosphorus and potassium* are now being removed from soils via harvested crops than added back in. This is due to reduced access to fertilisers during the war and inefficient farming practices. Military activity has also exacerbated existing degradation and erosion of soils across Ukraine.
The new study, led by the UK Centre for Ecology & Hydrology (UKCEH), has been published in the Nature journal Communications Earth & Environment.
It recommends better farm management of nutrients, such as taking advantage of animal manure as an organic fertiliser for croplands, more efficient use and application of fertilisers, and introducing legumes into crop rotations.
This would benefit soil health, food production and the environment. Surplus nutrients from fertilisers degrade soil health and leach into water, which can result in toxic algal blooms, while excess nitrogen additionally also contributes to air pollution and greenhouse gas emissions.**
Integrated management
Dr Sergiy Medinets of UKCEH, who led the study, said: "Unless action is taken to restore lost nutrients in soils, there is likely to be a long-term impact on crop production in Ukraine. This would not only affect food security in Ukraine but also globally – particularly North Africa and the Middle East which depend upon imports – and further push up prices and increase hunger.
"There is therefore an urgent need for an integrated nutrient management plan for Ukraine that wastes fewer nutrients and reduces the amount of synthetic fertiliser needed."
Dr Medinets explained this plan would involve more efficient use and precise application of synthetic and organic fertilisers. It would also include expanding the production of legumes such as beans, peas and lentils as well as cover crops – all of which are effective at removing nitrogen from the atmosphere and storing it in soils, making it available for subsequent crops.
Sharing expertise
The research, published in the Nature journal Communications Earth & Environment, involved scientists at UKCEH as well as Odesa National I.I. Mechnikov University (ONU) in Ukraine and Wageningen University & Research (WUR) in the Netherlands.
They used official statistics for fertiliser use and yields to estimate the balance of nutrients relating to the production of three key exported crops – wheat, maize and sunflower – in each region of Ukraine over the past 40 years. Together, the production of these three crops cover two-thirds of the country's agricultural land.
Ukraine became one of the world's major crop-exporting countries after independence, being the top global producer and exporter of sunflower meal, oil and seed, and among the top five maize and wheat exporters. But the war has reduced nutrient inputs, compromising long-term sustainability.
Study coauthor Professor Mark Sutton of UKCEH said: "We are optimistic that sharing expertise on nutrient management is another way in which the UK and other countries can support Ukraine's environment and economy at the same time."
Promoting greater efficiency
There has been a separation of arable and livestock agriculture in Ukraine in recent decades, so many farms no longer have easy access to animal manure to spread on to fields as a fertiliser. The number of livestock has fallen significantly but the study says 90% of the manure that is still produced is wasted – the equivalent of US $2.2 billion in fertiliser costs.
The authors therefore advocate more mixed farming and localised sustainable management of manure. They say farmers in Ukraine need information to persuade them of the economic and environmental benefits of taking action.
Many of the report's recommendations require little investment, meaning that, with community efforts, the shift towards more sustainable agriculture in Ukraine could start now, while the war continues. This would result in lower costs for farmers, maintained productivity and less impact on the environment.
Suggested measures include setting up local systems to collect surplus manure and redistribute it to other farms, using more efficient types of fertiliser and sharing knowledge from the Ukrainian farms already implementing more sustainable practices.
The report also calls for a national inventory of how much nitrogen, phosphorus and potassium that different crop variants remove from the soil – a key step towards an 'smart fertiliser planner', a software tool that would help farmers apply exactly what their crops need.
The authors say farmers also need financial support from their government and the international community, including through the Ukraine Recovery and Reconstruction Fund, to improve sustainable nutrient management. This would include helping them to buy machinery that applies synthetic and organic fertilisers to land more efficiently, and to build facilities to handle, store and treat manure.
From excess to deficiency
The scientists report that when Ukraine was part of the Soviet Union, there was over-use of fertilisers, resulting in excess nutrients in soils and environmental pollution. However, they conclude the opposite extreme now exists – insufficient amounts of the three key crop nutrients in agricultural soils.
Following Ukraine's independence, the use of synthetic phosphorus and potassium, most of which are imported, fell sharply and there have been insufficient amounts in soils across most of the country for the past 30 years, exacerbated by the war.
In contrast, the use of synthetic nitrogen fertiliser, which also initially declined in the 1990s, began to rise again – partly supported by domestic production. This later led to over-application in many areas. By 2021, Ukraine's rate of application of nitrogen fertiliser (per hectare), was among the highest in the world, but the war has resulted in usage falling significantly.
