Potassium deficiency in agricultural soils is a largely unrecognised but potentially significant threat to global food security if left unaddressed, finds new research involving researchers at UCL, University of Edinburgh and the UK Centre for Ecology & Hydrology.
The study, published in Nature Food, found that more potassium is being removed from agricultural soils than is being added, throughout many regions of the world. It also gives a series of recommendations for how to mitigate the issue.
Potassium is a vital nutrient for plant growth that helps with photosynthesis and respiration, the lack of which can inhibit plant growth and reduce crop yields. Farmers often spread potassium-rich fertilisers over their fields to replenish the depleted nutrient, but supply issues can inhibit its use, and there are lingering questions about its environmental impact.
The researchers report that globally, about 20% of agricultural soils face severe potassium deficiency, with particular regions likely to experience more critical shortages, including 44% of agricultural soils in South-East Asia, 39% in Latin America, 30% in Sub-Saharan Africa and 20% in East Asia, largely due to more intensive agricultural practices.
~~Pretty sure there are crops you can rotate in that replenish the soil.~~ Edited because crop rotation doesn’t produce Potassium as pointed out by replies — it’s a mineral. Organic waste does include potassium though.
There’s also a literal shitload of organic waste that humans generate that can be used for a similar purpose instead of burying it in landfills.
Potassium is produced by breaking down potassium-rich rocks. Plants cannot replenish it like they replenish nitrogen.
We do produce a lot of potassium-rich waste - sewage and food waste, for example - but most of it is also rich in other nutrients. So you can add a little of it, but adding too much of it can cause other problems (like eutrophication).
The other solution is to buy potassium fertiliser. A significant amount of this is produced in Russia, Kazakhstan and Ukraine, and I'm guessing its trade is being affected by the ongoing war.
I've read that plants with deeper roots can "bring up" nutrients from lower layers, which would help in the shorter term.
Longer term? No time to think about that..
This is possible, but plants with deep roots (shrubs, certain grasses and scrubs) usually take longer to grow.