6 March 2024

Potassium loss is a global threat: here are six actions to counter it

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Twenty percent of the world’s farmland has severe potassium deficiency. A study from Europe proposes a mix of strategies to protect food security

by Matteo Cavallito

 

Food security and healthy ecosystems are placed in jeopardy by poor potassium management,” says a group of scientists in a study published in the journal Nature Food. Deficiency of this element, in particular, can inhibit plant growth and thus reduce agricultural yields, according to a statement released by the UK Centre for Ecology & Hydrology (UKCEH), one of the organizations involved in the research along with the University of Edinburgh, University College London and the Institute of Environmental Assessment and Water Research (IDAEA) in Barcelona.

In addition, the authors continue, “Farmers often spread potassium-rich fertilisers over their fields to replenish the depleted nutrient, but supply issues can inhibit its use and there are also questions about the environmental impact.”

A problem for many soils on the Planet

Potassium, as we know, represents one of the key soil nutrients. Several phenomena are responsible for its loss, including leaching favored by rainfall to the very harvesting process that affects agricultural soils. Currently, the researchers note, about 20 percent of the world’s farmland is severely deficient in potassium.

The most critical situation is found in Southeast Asia where the share of deficient soils rises to 44 percent. The scenario in Latin America (39%) and sub-Saharan Africa (30%) is also problematic.

In this context, wise management of the resource therefore becomes crucial. “By wisely handling nutrients like nitrogen, phosphorus and potassium together,” explains Will Brownlie, researcher at the UK Centre for Ecology and Hydrology in Edinburgh and co-author of the survey, “we can reap multiple benefits: prevent pollution, boost crop yields and minimise nutrient loss. It’s about coordinating our approach for better farming outcomes.”

The potassium fertilizer issue

Tackling potassium loss would also help reduce the use of fertilizers that are typically applied to replenish fields with the same element. These products, in fact, can be particularly useful, but their impact in terms of cost and damage to the environment cannot be overlooked. The potassium fertilizer market is a nearly $20 billion market dominated by four countries-Canada, Russia, Belarus, and China-responsible alone for 4/5 of the global supply. These characteristics make price dynamics highly sensitive to geopolitical factors with all the obvious consequences.

The researchers, in particular, recall how in April 2022 the price of potash rose 500 percent over the previous year as a result of a “perfect storm” of factors, including the Russian invasion of Ukraine and the resulting Western sanctions on exports from Moscow and Minsk.

“Since then, the cost of potash has fallen by about 50%,” the authors explain. “But concerns remain that farmers will not be able to access sufficient fertiliser to maintain food supplies under the current system.” Moreover, potassium has also an environmental impact: “Potash mining generates millions of tonnes of refuse which can leach into soils and salinise soil and water tables, harming plants and animals.”

Six actions

The researchers then suggest six different actions to be conducted nationally and internationally:

  1. Set up a global assessment of current potassium stocks and flows to identify the most at-risk countries and regions
  2. Establish national capabilities for monitoring, predicting and responding to potassium price fluctuations
  3. Help farmers maintain sufficient soil potassium levels with further research about the yield implications of limited potassium in various crops and soils
  4. Evaluate the environmental effects of potash mining and developing sustainable application practices
  5. Develop a global circular potassium economy that maximises the reuse and recycling of the nutrient
  6. Increase intergovernmental cooperation through the UN and other agencies to develop global policy coordination akin to what’s been developed for nitrogen.

In this way, they say, it is possible to “prevent declines in crop yield due to soil potassium deficiency, safeguard farmers from potash price volatility and address environmental concerns associated with potash mining”.