Potassium As A Key Fertilizer In Combating Climate Change And Malnutrition
By Muhammad Yasir Khurshid
According to the Global Climate Risk Index, 2020, Pakistan is the 5th most vulnerable country to climate change and has paid a cost of nearly 10 thousand lives and 3.7 billion dollars to the national economy because of the ravages of climate change since the year 2000. Further worsening the situation, the future cost of the climate impact may increase to $14 billion per year over the next four decades (Eckstein et al., 2020). In recent years, Pakistan has witnessed the heatwave that resulted in the impairment of grain filling, especially in the Autumn Maize crop. Crop quality and nutrient status of the produce has also been deteriorating under such harsh conditions.
Climate change increases in local and global temperatures pose a significant threat to plant growth and crop production (Pareek, Dhankher and Foyer, 2020). If current rates of global warming continue, global temperatures will continue to increase by a further 1.5 °C between 2030 and 2052 (Intergovernmental Panel on Climate Change, 2018). Heat stress can impair all stages of plant growth from germination to reproduction, limiting the productivity of major staple food crops (Hussain et al., 2019). For example, heat stress has a negative impact on wheat yields. A 4–6% reduction in average global yields of wheat is predicted for each 1 °C increase in global mean temperature (Asseng et al., 2015).
Another grave reality of the world is malnutrition as 1 in 9 people suffer from nutrient deficiency, resulting in stunted heights and poor human growth. A healthy adult may require 3,400 mg of potassium on daily basis (National Institute of Health, 2019), and potassium fertilization at assures the concentration of K in wheat grains up to 5400 mg K/Kg (Hussain, 2020). According to FAO estimates, the world population will exceed 9 billion people by 2050. and world food production will have to be increased by 50% to meetup the requirements. Eradicating hunger on the planet and guaranteeing sufficient food production to feed an ever-growing world population are challenges that our society faces. For this, it is essential to increase agricultural production and the role that potassium fertilization plays in this regard is irrefutable.
Many of the environmental problems related to agriculture will continue to exist in the coming years. It is also important to not only mitigate the adverse impacts of climate change but also to feed the coming generations on a sustainable basis. Soils must be fertilized to maintain the adequate content of mineral elements that crops need for their correct development through their absorption at the precise moment and in the necessary quantities. Fertilized soils guarantee greater food production, cut the price of agricultural products, and improve the lives of the farmer and his environment. Scientists emphasized the importance of judicious use of potassium as a key fertilizer in combating the detrimental effects of global warming and changing climate in a conference organized by Engro Fertilizers and MNS University of Agriculture, Multan. Potassium plays many important roles that enable the crop plants to not only withstand the harsh climate and extremes but also play decisive roles in yield and production. Potassium strengthens the vascular bundle to transport water within the plant body, so it increases its resistance towards disease, especially under high temperatures.
Potassium is an essential component in living beings and plays a fundamental role in the growth of plants. Potassium is indispensable for plant growth and yield building, and not just in low water or dry conditions, even under optimal growing conditions, potassium fertilization pays off. But, in a year of drought, it is even more effective: the plant is under stress and benefits even more from the positive effects of nutrients. Trials advocate the application of potassic fertilizer (Pettigrew, 2008) and highlight the prospects of potassium solubilizing microbes for yield enhancement (Ali et al., 2020). Value addition of potassium fertilizers to minimize the potash losses is a great challenge of the fertilizer industry. The specialty fertilizer industry transforms the mineral nutrients for value addition in many ways including polymer and microbial coatings which significantly reduces the nutrient losses and usability by the crop plants. These nutrients are in forms that can be assimilated by plants. It results in the form of increased production with high grain mineral contents but also improves the flavor, taste, and shelf life of the produce. Sardans and Peñuelas (2015) has reviewed the functions of potassium in crop plants and connoted that potassium regulates the function of opening and closing of the leaf stomata and consequently transpiration of the plant. Thus, a good potassium supply makes it possible to reduce unproductive water losses. The potassium is important for photosynthesis and to promote transport of assimilates from photosynthesis to the roots and storage organs. Thus, it actively participates in good root growth, a key factor in building yield. With a more developed root system, which can absorb water from deeper layers of the soil, the plant will be able to withstand long periods of drought. Potassium increases the water holding capacity of the soil so that more water available to plants, their growth, formation, and performance. It directly influences photosynthesis through action on chloroplasts and indirectly through its influence on the stomata closure mechanism. It participates in the activation of more than 50 enzymes in the metabolism of the plant, thus it Improves the formation of carbohydrates such as sugar and starch, and facilitates the transport and storage of carbohydrates from the leaves to the storage organs. Incorporation of potassium also enhances the uptake of Zn with up to 75 % increment in Zn contents in grains (Hussain et al., 2020). Thus, the use of potash not only increases the chances of survival under changing climate conditions but also imparts high resilience in terms of crop productivity for the coming generations. The use of value-added potassium fertilizer will assure the cost-cutting due to curbing losses and increase productivity, and it is a frontline weapon in combating with devouring threat of climate change.
Ali, A. M., Awad, M. Y., Hegab, S. A., Gawad, A. M. A. E., & Eissa, M. A. (2020). Effect of potassium solubilizing bacteria (Bacillus cereus) on growth and yield of potato. Journal of Plant Nutrition, 1-10.
Eckstein, D., Künzel, V., Schäfer, L., & Winges, M. (2020). Global Climate Risk Index 2020: who suffers most from extreme weather events? Weather-related loss events in 2018 and 1999–2018. Germanwatch, Bonn.
Hussain, S., Shah, M. A. A., Khan, A. M., Ahmad, F., & Hussain, M. (2020). Potassium Enhanced Grain Zinc Accumulation In Wheat Grown On A Calcareous Saline-Sodic Soil. Pak. J. Bot, 52(1), 69-74.
National Institutes of Health. (2019). Potassium Fact Sheet for Health Professionals. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/
Pareek, A., Dhankher, O. P., & Foyer, C. H. (2020). Mitigating the impact of climate change on plant productivity and ecosystem sustainability. Journal of Experimental Botany, 71(2), 451-456.
Pettigrew, W. T. (2008). Potassium influences on yield and quality production for maize, wheat, soybean and cotton. Physiologia plantarum, 133(4), 670-681.
Sardans, J., & Peñuelas, J. (2015). Potassium: a neglected nutrient in global change. Global Ecology and Biogeography, 24(3), 261-275.
Potassium As A Key Fertilizer In Combating Climate Change And Malnutrition
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Social media posts claim the Pfizer-BioNTech Covid-19 vaccine is “poison” because it contains potassium chloride -- a chemical also used to stop the heart during a process of lethal injection. The claim is false; the coronavirus vaccine was tested for safety in clinical trials, and medical experts say the minimal amount of potassium chloride used in the shot will not harm recipients.
“Pfizer’s vaccine got the same poison, that they use with USA lethal injections at the prisons. It’s called POTASSIUM CHLORIDE,” claims a December 20, 2020 tweet.
A December 18, 2020 tweet, also calling the vaccine “poison,” includes an image of the product information for the Pfizer-BioNTech shot along with the text, “Pfizer’s Covid-19 vaccine comes with potassium chloride - the same drug used for executions of death row inmates!”
Screenshot of a tweet taken on January 6, 2021
The image can be found on Instagram, including in one post claiming, “It’s a cocktail of poison y’all!!!”
It was also shared hundreds of times on Facebook as the United States and Canada approved the Pfizer-BioNTech Covid-19 vaccine for emergency use in December amid rising numbers of coronavirus infections.
However, potassium chloride is a natural substance, regulated by the human body.
Libby Richards, associate professor at the Purdue School of Nursing, told AFP by email: “Potassium chloride is found in almost all of the food we eat -- meats, fruits, cereals, chips, baby formulas.
“If you drink bottled water, you are drinking potassium chloride which is then absorbed into your bloodstream.”
Asked about its use in vaccines, Richards said: “The ingredients in vaccines are carefully chosen and very closely monitored for safety.
“The amount of potassium chloride found in vaccines is very, very small and absolutely considered a safe amount.”
According to the US Food and Drug Administration, each dose of the Pfizer-BioNTech Covid-19 vaccine contains .01 milligram of potassium chloride.
That is “equivalent to a pinch of salt,” Scott Halperin, director of the Canadian Centre for Vaccinology, explained by phone.
Halperin, who teaches at Canada’s Dalhousie University, said that potassium chloride is used in many vaccines because it is a salt, and “when making a viral vaccine, you need to have the proper amount of salts to keep cells alive. Because it’s a natural product that all cells need, it’s also put into cell cultures.”
Pfizer-BioNTech was the first to complete a large-scale, phase 3 clinical trial for a Covid-19 vaccine on patients older than 16. It was found to confer 95 percent protection against the virus with no serious safety issues.
Both the US Centers for Disease Control and Prevention and Health Canada are carefully monitoring all adverse effects to the vaccine as it is offered to larger portions of the population.
AFP Fact Check previously reported on misleading claims about potassium chloride in vaccines here. More reporting on misinformation surrounding the Pfizer-BioNTech Covid-19 vaccine is available here.
Potassium chloride in Pfizer-BioNTech Covid-19 vaccine is not dangerous
Potassium Deficiency in Cotton a Concern for Producers
Potassium deficiency in cotton across the Southeast is a major problem for producers, even more so this year, says Glen Harris, University of Georgia soil fertility and Extension specialist.
“It’s been a continuing problem. In my opinion, I think we do a decent job with nitrogen. We don’t seem to have a lot of phosphorus problems. Potassium is probably our No. 1 nutrient issue every year,” Harris said. “It kind of comes and goes but this seemed to be one of those years where we saw a lot of it.”
Why Does it Happen?
Theories vary on why the nutrient came up short this year in cotton plants. Some believe the rainfall in the late summer and fall contributed to its deficiency, especially since it is mobile in the soil. However, Harris said it is not as mobile as nitrogen and we have experienced decent rainfall in prior years and did not have unusual potassium.
“I really wonder if there’s other things going on. I think part of it is, we’re seeing higher calcium levels and I think that’s starting to interfere with potassium uptake,” Harris said. “People for some reason are running their pH’s higher which also usually comes with higher calcium levels. Calcium competes with magnesium to get into the plants. That’s a theory, but I’m wondering if that had something to do with it.”
Potassium is one of the primary nutrients plants need to grow.
“Carbon, hydrogen and oxygen are the top three, but we don’t talk a lot about those because we get them free from air and water. The next three are N (nitrogen), P (phosphorous), K (potassium) and I rank them N-first, K-second, probably for Georgia cotton as far as need,” Harris said.
Potassium deficiency itself is detrimental to the plant. But it could also lead to secondary problems like the fungal disease leaf spot.
“If you read the textbook, it’ll say the older leaves will turn yellow and eventually turn yellow around the outside like dead tissue around the edge of the leaf. My experience has been, it’ll occur almost on the leaves of the whole plant. We also get leaf spots that will come in, too,” Harris said. “We’ve seen enough of it over the years, people are pretty good at diagnosing it, which is also kind of scary because we think we know what to do to avoid the problem and we know what it looks like when it shows up, but we keep getting it. That is concerning.”
How to Avoid Potassium Deficiency
There are various ways to combat this nutrient deficiency. Do not wait too late to apply potash. Soil test and grid sample, since most of the time, these instances will occur in patches in the field. Also, do not split your fertilizer applications. Apply all at planting.
Potassium Deficiency in Cotton a Concern for Producers
Why is potassium the cation of life?
A new hypothesis explores how potassium came to be the dominant biological cation.
Image credit: Dan-Cristian Pădureț on Unsplash
Why is it that in all living cells there is a higher concentration of potassium (K+ ions) in the cytoplasm than in the surrounding medium, and the reverse for sodium (Na+ ions)? This certainly isn’t chance, because both prokaryotes (bacteria and archaea) and eukaryotes have evolved quite complicated ways of keeping things this way.
The actively-maintained imbalance of ions across a cell membrane (more K+ inside, and more Na+ and Cl– outside) typically produces a potential difference of between -40 and -70 millivolts (mV) across the cell membrane — human neurons, for example, have a membrane potential of -70 mV.
That doesn’t sound like much, but this voltage exists over a tiny width of “insulator” (the lipid bilayer, cell membrane) — between 5 and 10 nanometers — so the power stored up in that system is very impressive. Compare this to a single cell in a lithium-ion battery, which has a porous charge separator of around 150 micrometers thick (roughly 25,000 times the thickness of a cell membrane) across which exists a voltage of, say, 1.7 volt (25 times more than in a living cell).
Seen this way (though it is not quite that simple), the living cell does one thousand times better than a battery at separating charge! To find out how it manages to make the K+ gradient, we must start with early evolution: with bacteria. And because we know that cations (or anions, for that matter) can’t pass through the lipid bilayer of a cell, it must have something to do with the membrane proteins — specifically, ion channels.
Basically, it’s all about the peptide chain carbonyl groups (O-C=O) that line the channel interior (the pore). The oxygens, possessing a high partial negative charge, temporarily associate with K+ ions, making a kind of static-charge-attractor (eight-fold coordination of C=O to K+, for those who like details). Sodium ions, being smaller than potassium ions, don’t “fit” in this particular channel: they have their own, specific, electrostatic attractor channel. So, that solves the question of ion selectivity, but what drives K+ ions against a concentration gradient that can reach 25–30 times the external concentration?
For this, we must imagine the challenge that bacteria have in keeping a physiologically ambient pH in their cytoplasm; a very important concept, for many proteins — and hence their functions, e.g. enzymatic — are exquisitely sensitive to the acidity of their environment. Equally important, the cell membrane is very sensitive to voltages over 200 mV.
These two physiological constraints lead us to protons (H+) as the driving evolutionary force because they are also the force that powers bacteria: prokaryotes pump protons out of their cytoplasm as a way of building up potential energy (a kind of battery for storing energy), to let them back in again through an enzymatic channel (the F1-F0 ATPase) to make a form of energy (ATP) that can be used as a common currency in the cell (chemical energy). Rapidly growing bacteria need so much energy that their proton pumps can generate dangerously high proton gradients, which can destroy their cell membranes even more quickly than disrupting enzyme mechanisms in the cytoplasm (via pH change) — in a matter of a few millisecond the cell can simply “dissolve” in an electrostatic catastrophe! K+ ions are the cell’s safety mechanism, because they electrostatically off-set H+ ions, moving in, as the protons move out.
So, this is how the K+ gradient evolved; and via the incorporation of an alpha-proteobacterium into the pre-cursor of eukaryotic cells, the pre-cursor of mitochondria, it spread into the eukaryotic domain of life to become a universal feature.
The conditions under which it developed (notably, protecting against pH changes) are not the forces that keep K+ at the centre of eukaryotic cytoplasmic stability today, but evolution often works with what it has been given, and finds other “uses” — in eukaryotic cells, these are related to the electrostatic charge on the DNA-binding proteins, histones, which bacteria do not possess, and the disassembly of chromatin for transcription and DNA replication. Here we also see why K+ and not Na+ is the cation that cells “chose”.
Reference: Nikolay Korolev, How potassium came to be the dominant biological cation: of metabolism, chemiosmosis, and the cation selectivity since the beginnings of life, BioEssays (2020). DOI: 10.1002/bies.202000108
Why is potassium the cation of life?