Scientists have warned that low soil potassium levels caused by global sanctions imposed on Russia and Belarus pose a serious threat to global food security if left unchecked.
Potassium is an essential nutrient for plants as it facilitates photosynthesis and respiration, which are essential for plant growth and a successful harvest. However, a British team of researchers says intensive harvesting removes more potassium from agricultural soils than is added to fertilizers.
According to a study by University College London (UCL), the University of Edinburgh and the UK Center for Ecology and Hydrology, which makes a number of recommendations on the issue, around 20% of agricultural land is deficient in potassium.
Will Brownlee, senior research project manager at the UK Center for Ecology and Hydrology in Edinburgh and lead author of the study, published this week (19 June and 19 February) in the journal Nature Food, commented: “Potassium deficiencies often go unnoticed until crop yields decline“
He added that the lack of regular testing for potassium in soils and plant tissues in many parts of the world does not contribute to monitoring.
Price increase
The regions of the Global South with the largest deficits are Southeast Asia (44%), Latin America (39%) and sub-Saharan Africa (30%). Traditionally, farmers fertilized their fields with potassium-rich fertilizers to replenish depleted nutrients.
But scientists say supply chain disruptions and rising prices are hampering use as farmers rely on nitrogen and phosphorus to boost yields.
Research shows that the price of potash, the main ingredient in potash fertilizers, was 500% higher in April 2022 than the previous year, due to a “perfect storm” of factors including increased demand for fertilizers, rising fuel prices and the economy Recovery after the Covid-19 pandemic and the Russian invasion of Ukraine.
As a result, many farmers have limited their use of potash, Brownlee said.
Russia and Belarus together export about 42% of the world’s potash supply, but after Russia invaded Ukraine in 2022, Britain, the US, Canada and the EU imposed sanctions on imports to both countries, disrupting global supplies and increasing prices .
Scientists warn that potash prices have fallen about 50% since the initial spike but are still high, raising fears that farmers will not have enough fertilizer to maintain food supplies.
Co-author Peter Alexander, senior lecturer in geosciences at the University of Edinburgh, said: “Potassium price fluctuations have important implications for the global food system. Access to potassium is essential for farmers to maintain crop yields, but current high potassium prices make access difficult for the most vulnerable.“.
Take action against potassium deficiency
The scientists made six recommendations, including better potassium management and strong intergovernmental coordination mechanisms. There are currently no national or international guidelines or regulations governing the sustainable management of soil potassium, similar to the systems established for other important plant nutrients such as nitrogen and phosphate.
Brownlee said recycling organic waste is a simple solution. “This is about safely reintroducing nutrient-rich materials such as human waste, fertilizers and food waste into the agricultural system.”, Explain. “The transition to these closed systems is necessary not only for sustainable development, but also to protect farmers from fluctuations in international fertilizer markets.“.
Other recommendations include regular examination of soil and plant tissue to determine specific nutrient needs of plants, correct application of fertilizers according to growth needs, and measures to minimize soil erosion and runoff, which can lead to nutrient losses in rivers and groundwater.
Inadequate levels of one nutrient can limit crop yields and reduce the uptake of other nutrients from the soil, he said, adding: “Consequently, these unused nutrients may be more vulnerable to environmental loss than to being used by crops. Therefore, a holistic approach to nutrient management is essential for sustainable agriculture.“.
Geoffrey Waweru, a soil scientist at the Jomo Kenyatta University of Agriculture and Technology in Kenya, welcomed the study’s results as timely.
He believes the importance of potassium in agriculture should not be underestimated, especially for crop health in the face of climate change. “The recommendations are very well written.“, said, “The recommendations are very well written, but I don’t know to what extent they take into account the effects of potassium, especially its crucial role in photosynthesis and the opening of the stomata that regulate transpiration.“.
“This is particularly important because climate change will impact how plants use water.“he added.
With information from:
