Strictly speaking, penetration occurs when a projectile enters a target without passing through it and "perforation" occurs when the projectile completely passes through the target, but the word "penetration" is commonly used to refer to either.

Penetration into a "semi-infinite" or "massive" target is penetration (in the strict sense of the word) of targets so thick that the level of penetration is not affected by the target's thickness. There is a "transition region" between semi-infinite penetration and perforation, in which the target is not perforated but the projectile, as it nears the back face of the target, meets reduced resistance and is capable of penetrating a greater distance than it would in a semi-infinite target. This effect is variously named the back or rear surface, plate, or face effect and is also present when perforation occurs.

A penetrating projectile may cause the target to break into multiple pieces, spewing from both the front and back of the target, themselves at high velocity. These pieces are collectively referred to as spall. Spall can be generated even if a perforation is not achieved (the projectile fails to pass through the target), generated instead by the shock wave generated by the impact of the projectile.

Bombs designed for great penetration into the earth or for perforation of hardened targets are known as bunker busters.

Because the black cherry tree is the preferred host tree for the eastern tent caterpillar, one approach to prevention is to simply remove the trees from the vicinity of horse farms, which was one of the very first recommendations made concerning MRLS. Next, because the brief time for which the full-grown ETCs are on the ground in the vicinity of pregnant mares, simply keeping pregnant mares out of contact with them is also an effective preventative mechanism. In this regard, one Kentucky horse farm took the approach of simply muzzling mares during an ETC exposure period, an approach which was reportedly effective.

No effective treatment for MRLS is apparent. Mares which aborted are treated with broad-spectrum antibiotics to avoid bacterial infections. The foals born from mares infected with MRLS are given supportive care and supplied with medication to reduce inflammatory response and improve blood flow, but none of the treatments appears to be effective, as the majority of the foals do not survive. Unilateral uveitis is treated symptomatically with antibiotics and anti-inflammatory drugs.

When the SPSE mechanism explaining MRLS was identified, it was immediately apparent that the model might be an ancient defensive mechanism of caterpillars, and that MRLS-like syndromes might well exist and be identified elsewhere. In 2004, Dr. Thomas Tobin was contacted by a horse farmer in NSW, Australia, who was faced with what she believed were caterpillar-related abortions on her farm in eastern Australia. She put Tobin in touch with the investigating veterinarian, Dr. Nigel Perkins, who at that time understood the Kentucky MRLS outbreak to be black cherry tree/cyanide-driven. Advice to Dr. Perkins was brief and unequivocal—given the similarities between MRLS and the syndrome he was describing and the possible role of caterpillars in his syndrome, his experimental approaches should be to first test the caterpillars, any and all other abortigenic candidates, test second. Following this advice, the recommended caterpillar administration experiments were performed and the local processionary caterpillar was identified as the cause of the Australian caterpillar-driven abortion syndrome, which was named "Equine Amnionitis and Fetal Loss."

A further indication of the possible ubiquity of caterpillar-related abortions comes from the western Sahara, where traditional camel pastoralists/herders have long known that pregnant camels exposed to caterpillars are at high likelihood of abortion or birth in a condition similar to the late-term MRLS fetuses. In the western Sahara, the condition is known as "duda", the local term for caterpillar, and the link to the caterpillar is very well understood in the local Saharan camel pastoralist cultures. Considering the difficulty that certain groups in Kentucky had in accepting the theory of caterpillars causing MRLS, the long-time familiarity of a traditional camel-herding culture with the concept of caterpillar-driven abortions is interesting.

Skeletal eroding band (SEB) is a disease of corals that appears as a black or dark gray band that slowly advances over corals, leaving a spotted region of dead coral in its wake. It is the most common disease of corals in the Indian and Pacific Oceans, and is also found in the Red Sea.

So far one agent has been clearly identified, the ciliate "Halofolliculina corallasia". This makes SEB the first coral disease known to be caused by a protozoan. When "H. corallasia" divides, the daughter cells move to the leading edge of the dark band and produce a protective shell called a lorica. To do this, they drill into the coral's limestone skeleton, killing coral polyps in the process.

A disease with very similar symptoms has been found in the Caribbean Sea, but has been given a different name as it is caused by a different species in the genus "Halofolliculina" and occurs in a different type of environment.

The psychological effects of occupational needlestick injuries can include health anxiety, anxiety about disclosure or transmission to a sexual partner, trauma-related emotions, and depression. These effects can cause self-destructive behavior or functional impairment in relationships and daily life. This is not mitigated by knowledge about disease transmission or PEP. Though some affected people have worsened anxiety during repeated testing, anxiety and other psychological effects typically abate after testing is complete. A minority of people affected by needlestick injuries may have lasting psychological effects, including post-traumatic stress disorder.

Due to the high number of hosts, eradication of tungiasis is not feasible, at least not easily so. Public health and prevention strategies should then be done with elimination as the target. Better household hygiene, including having a cemented rather than a sand floor, and washing it often, would lower the rates of tungiasis significantly.

Though vaccines would be useful, due to the ectoparasitic nature of chigoe flea, they are neither a feasible nor an effective tool against tungiasis. Nevertheless, due to the high incidence of secondary infection, those at risk of tungiasis should get vaccinated against tetanus. A better approach is to use repellents that specifically target the chigoe flea. One very successful repellent is called Zanzarin, a derivative of coconut oil, jojoba oil, and aloe vera. In a recent study involving two cohorts, the infestation rates dropped 92% on average for the first one and 90% for the other. Likewise, the intensity of the cohorts dropped by 86% and 87% respectively. The non-toxic nature of Zanzarin, combined with its "remarkable regression of the clinical pathology" make this a tenable public health tool against tungiasis.

The use of pesticide, like DDT, has also led to elimination of the "Tunga penetrans", but this control/prevention strategy should be utilized very carefully, if at all, because of the possible side effects such pesticides can have on the greater biosphere. In the 1950s, there was a worldwide effort to eradicate malaria. As part of that effort, Mexico launched the Campaña Nacional para la Erradicación de Paludismo, or the National Campaign for the Eradication of Malaria. By spraying DDT in homes, the Anopheles a genus of mosquitoes known to carry the deadly Plasmodium falciparum was mostly eliminated. As a consequence of this national campaign, other arthropods were either eliminated or significantly reduced in number, including the reduviid bug responsible for Chagas disease (American Trypanosomiasis) and "T. penetrans". Controlled, in-home spraying of DDT is effective as it gives the home immunity against arthropods while not contaminating the local water supplies and doing as much ecological damage as was once the case when DDT was first introduced.

While other species gradually gained resistance to DDT and other insecticides that were used, "T. penetrans did" not; as a result, the incidence of tungiasis in Mexico is very low when compared to the rest of Latin America, especially Brazil, where rates in poor areas have been known to be as high or higher than 50%. There was a 40-year period with no tungiasis cases in Mexico. It was not until August 1989 that three Mexican patients presented with the disease. Though there were other cases of tungiasis reported thereafter, all were acquired in Africa.

The treatment of an ingrown toenail partly depends on its severity.

If the status of the source patient is unknown, their blood should be tested for HIV as soon as possible following exposure. The injured person can start antiretroviral drugs for PEP as soon as possible, preferably within three days of exposure. There is no vaccine for HIV. When the source of blood is known to be HIV positive, a 3-drug regimen is recommended by the CDC; those exposed to blood with a low viral load or otherwise low risk can use a 2-drug protocol. The antivirals are taken for 4 weeks and can include nucleoside reverse transcriptase inhibitors (NRTIs), nucleotide reverse transcriptase inhibitors (NtRTIs), Non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), or fusion inhibitors. All of these drugs can have severe side effects. PEP may be discontinued if the source of blood tests HIV-negative. Follow-up of all exposed individuals includes counseling and HIV testing for at least six months after exposure. Such tests are done at baseline, 6 weeks, 12 weeks, and 6 months and longer in specific circumstances, such as co-infection with HCV.

Rainscald normally heals on its own, however as the condition can spread to involve large areas, prompt treatment is recommended. Although some cases can be severe, most rain scald is minor and can be easily and cheaply treated at home naturally.

First groom the affected parts carefully, to remove any loose hair. Be extremely gentle, the area is very sore itchy and horses will very quickly get fidgety. Next shampoo the area, use warm water and a soft cloth or brush, and massage the lather through the coat as much as the horse will tolerate. It is best to use Neem shampoo here, as this will treat as well as clean, but any mild shampoo is fine. Remove as much water as possible and dry the horse off, either use a hair drier or let him/her stand in the sun until completely dry. It is important not to let the horse roll! The rain scald bacteria may be picked up from the soil.

When the horse is completely dry, gently brush off any more loose hair. Next apply a salve or cream containing a high percentage of neem oil, or even pure neem oil, to liberally coat the affected area. Rub it in using fingertips, massage the area as much as the horse will tolerate. This will be very greasy. Smooth the hair back down and apply a rug to keep the horse dry, this prevents the neem being washed off as well as protecting from more dampness issues. Turn the horse out as normal.

Check it every day, and reapply the neem salve/cream if it seems to have dried away. The area should remain greasy with neem. Every 2–3 days or so, go through and scrape/pick off as much of the scabs as possible without upsetting the horse or making it bleed, then reapply the neem. Typically there will be improvement in a few days, and in a week there'll be some sign of new hair growing back. More severe rain scald may take longer.

Once all the scabs are gone and there is new hair fuzz growing in all over, use neem shampoo to clean the area of greasy residue, and dry well. Keep the horse covered for some time after rain scald has been treated, particularly in wet weather. Do not allow the skin to remain damp. It is advisable to shampoo the horse after riding or exercising, to remove sweat, which may encourage rain scald conditions, and make sure the coat is completely dry afterwards.

This treatment works in many ways. First, shampooing cleans the area of any contaminants, remove a lot of loose hair and scabs, and the rubbing stimulates the circulation. The neem is an antifungal agent, and works to eliminate the bacteria that cause the infection. It soothes the irritation in the area, and its greasiness provides the ideal environment for the raw skin to heal and grow new hair. It also helps to soften and lift the scabs. The new hair cannot grow in until those scabs are removed from the surface, but they are very painful to pick and remove, and most horses are intolerant of this procedure. After the neem has soaked into these scabs they will come away much more freely, and soon new hair will grow through.

In conventional treatment, scabs are softened with benzoyl peroxide and chlorhexidine and removed in order to speed the healing process. In severe or chronic cases, penicillin and streptomycin are injected into the horse to kill the bacteria.

Typically the disease is not life-threatening, nor does it impact the welfare of the horse, so treatments are more for the owner's sake of mind and cosmetic appeal of the animal.

In order to prevent rainscald, it is important to stop the spread of the bacteria. Tick and insect control is an effective way to stop the spread of the bacteria from one animal to another. As well, separating infected animals will help to stop the spread of the bacteria. Keeping the animal in a dry, well-ventilated area out of the rain and wet conditions will stop the bacteria from growing. This dry environment includes dry ground as well as dry air.

Penile fracture is a medical emergency, and emergency surgical repair is the usual treatment. Delay in seeking treatment increases the complication rate. Non-surgical approaches result in 10–50% complication rates including erectile dysfunction, permanent penile curvature, damage to the urethra and pain during sexual intercourse, while operatively treated patients experience an 11% complication rate.

In some cases, retrograde urethrogram may be performed to rule out concurrent urethral injury.

Mild to moderate cases are often treated conservatively with warm water and epsom salt soaks, antibacterial ointment and the use of dental floss. If conservative treatment of a minor ingrown toenail does not succeed, or if the ingrown toenail is severe, surgical treatment may be required. A "gutter splint" may be improvised by slicing a cotton-tipped wooden applicator diagonally to form a bevel and using this to insert a wisp of cotton from the applicator head under the nail to lift it from the underlying skin after a foot soak.

Skeletal eroding band is visible as a black or dark gray band that slowly advances over corals, leaving a spotted region of dead coral in its wake. The spotted area distinguishes skeletal eroding band from black band disease, which also forms an advancing black band but leaves a completely white dead area behind it.

Skeletal eroding band was first noticed in 1988 near Papua New Guinea and then near Lizard Island in Australia's Great Barrier Reef, but was regarded as a gray variant of black band disease, as were instances off Mauritius in 1990. Surveys in 1994 in and around the Red Sea first identified the condition as a unique disease. It is now considered the commonest disease of corals in the Indian and Pacific Oceans, especially in warmer or more polluted waters.

The spread of the disease across an infected coral has been measured at in the Red Sea and around the Great Barrier Reef. Corals of the families Acroporidae and Pocilloporidae are the most vulnerable to infection. A study in 2008 found that the infection spread at about per day in colonies of "Acropora muricata", eventually wiping out 95% of its victims. However, experiments showed that the disease easily spread to already dead and dying areas of corals but did not attack undamaged corals.

As the disease is self-limiting, at least when exposure to the parasite is limited, management is mostly confined to treatment. Due to the secondary infection that can cause serious medical issues, the recommended course of action upon diagnosis is a surgical extraction of the fleas followed by the application of a topical antibiotic. Care should be taken to avoid tearing the flea during the extraction procedures as severe inflammation will result. The same will occur if part of the flea is left behind. Sterile equipment should always be used, as contaminated instruments could act as mechanical vectors for pathogens to enter the body.

There is no drug that has proven to be effective against embedded fleas. Oral niridazole was once considered a therapeutic drug, but well-designed studies are lacking and, given the severe adverse effects, this is one drug that is likely to cause more harm than good. However, it has some anecdotal evidence of lysing the fleas altogether. Oral ivermectin is considered by some in endemic areas to be a panacea against the fleas but studies using high doses have failed to validate this hypothesis. Other drugs such as topical ivermectin and metrifonate have been somewhat successful, but not enough to be significant. [2,5] For superinfections, trimethoprim, sulfamethoxazole, metronidazole, amoxicillin, (with/without clavulanate) have been used successfully, though these treat only secondary infections.

Successful topical treatments also include cryotherapy and electrodesiccation of the lesion. If formaldehyde, chloroform, or DDT are used topically, care should be taken when dealing with the resulting morbidity. The "T. penetrans" flea can also be suffocated using occlusive petrolatum, while Vaseline will kill the organism as well, most likely due to suffocation as the stigmatas would be covered. The gum of the mammee apple ("Mammea americana"), a fruit that also goes by the name Saint Domingo apricot, has also been used to kill the chigoe flea, though this has not been reported in the main "T. penetrans" literature.

Even without treatment, the burrowed fleas will die within five weeks and are naturally sloughed off as the skin sheds.

The smear layer is a layer of microcrystalline and organic particle debris that is found spread on root canal walls after root canal instrumentation. It was first described in 1975 and much research has been performed since then to evaluate its importance in assisting or preventing the penetration of bacteria into the dentinal tubules. More broadly, it is the organic layer found over all hard tooth surfaces.

Chronic exposure to human nail dust is a serious occupational hazard that can be minimized by not producing such dust. Best practice is to avoid electrical debridement or burring of mycotic nails unless the treatment is necessary. When the procedure is necessary, it is possible to reduce exposure by using nail dust extractors, local exhaust, good housekeeping techniques, personal protective equipment such as gloves, glasses or goggles, face shields, and an appropriately fitted disposable respirators to protect against the hazards of nail dust and flying debris.

Subcutaneous cysts may be surgically opened to remove less mature bots. If more matured, cysts may be opened and "cuterebra" may be removed using mosquito forceps. Covering the pore in petroleum jelly may aide in removal. If larvae are discovered within body tissues, rather than subcutaneously, surgical removal is the only means of treatment. Ivermectin may be administered with corticosteroids to halt larval migration in cats presenting with respiratory cuterebriasis, but this is not approved for use in cats. There is not yet a known cure for cerebrospinal cuterebriasis.

Healthcare providers may use podiatry drills on onychauxic (thickened) nails of patients to alleviate or eliminate pain, prevent or treat subungual ulcerations, allow better penetration of topical antifungal agents, or improve cosmesis, all in effort to improve the patient’s “quality of life.” In a study conducted by Miller, 65% of respondents reported routinely drilling thickened toenails. However, the improved effectiveness of antifungal drugs such as itraconazole and terbinafine reduces the need to drill these infected nails.

Podiatry drills have a mechanical rotating burr that can be set at a range of speeds usually up to 12,000 rpm and may or may not have an integrated local ventilation extraction system. Even with the most effective dust extractors, the electric nail debridement process is not totally risk free because the extractors range from 25% - 92% effective in reducing airborne particles. While the large particles settle out to the floor, varying amounts of smaller particles remain suspended and are inhaled by or adhere to the practitioner and clinical environment. The particle sizes range from 0.1 to 100 um and 86% of these particles are less than 5 um in diameter and therefore capable of entry into the alveoli.

Cuterebriasis is a parasitic disease affecting rodents, lagomorphs (hares, rabbits, pikas), felines and canines. The etiologic agent is the larval development of bot flies within the "Cuterebra" or "Trypoderma" genera, which occurs obligatorily in rodents and lagomorphs, respectively. Felines and canines serve as accidental hosts, but research suggests only by "Trypoderma" spp. Entrance into the body by first instar larva occurs via mucous membranes of natural orifices or open wounds as opposed to direct dermic penetration.

Clark-Holke et al. (2003) focused on determining the effect of the smear layer on the magnitude of bacterial penetration through the apical foramen around obturating materials. Thirty extracted teeth were classified into two test groups; the first group had the smear layer removed by rinsing with 17% EDTA while in the second group the smear layer was left intact. Canal preparation and obturation using lateral condensation, gutta-percha, and AH 26 sealer was performed on all of the teeth. The model systems consisted of an upper chamber attached to the cemento-enamel junction and a lower chamber at the apices of the teeth. Standardized bacterial suspensions containing "Fusobacterium nucleatum", "Campylobacter rectus" and "Peptostreptococcus micros" were inoculated into the upper chambers. Models were incubated anaerobically at 37 degrees C. Leakage results were as follows: In the first group 6 teeth showed bacterial leakage, the second group and third groups showed no bacterial leakage. This study indicated that removal of the smear layer reduced the leakage of bacteria through the root canal system.

Kokkas et al. (2004) examined the effect of the smear layer on the penetration depth of three different sealers (AH Plus, Apexit, and a Grossman type-Roth 811) into the dentinal tubules. Sixty four extracted human single-rooted teeth were used and divided into two groups. The smear layer remained intact in all the roots of group A. Complete removal of the smear layer in group B was achieved after irrigation with 3 ml of 17% EDTA for 3 min, followed by 3 ml of 1% NaOCl solution. Ten roots from each group were obturated with AH Plus and laterally condensed gutta-percha points. The same process was repeated for the remaining roots by using sealers Apexit and Roth 811 correspondingly. After complete setting, the maximum penetration depth of the sealers into the dentinal tubules was examined in upper, middle, and lower levels. The smear layer prevented all the sealers from penetrating dentinal tubules. In contrast, in smear layer–free root canals, all the sealers penetrated dentinal tubules, although the depth of penetration varied between the sealers. Furthermore smear layer adversely affected the coronal and apical sealing ability of sealers.

Çobankara et al. (2004) determined the effect of the smear layer on apical and coronal leakage in root canals obturated with AH26 or RoekoSeal sealers. A total of 160 maxillary anterior teeth were used. Eight groups were created by all possible combinations of three factors: smear layer (present/absent), leakage assessment (apical/coronal), and sealer used (AH26/Roeko-Seal). All teeth were obturated using lateral condensation technique of gutta-percha. A fluid filtration method was used to test apical or coronal leakage. According to the results of this study, the smear (+) groups displayed higher apical and coronal leakage than those smear (-) groups for both root canal sealers. Apical leakage was significantly higher than coronal leakage for both root canal sealers used in this study. It was determined that that removal of the smear layer has a positive effect in reducing apical and coronal leakage for both AH26 and RoekoSeal root canal sealers.

However Bertacci et al. (2007) evaluated the ability of a warm gutta-percha obturation system Thermafil to fill lateral channels in the presence or absence of the smear layer. Forty single-rooted extracted human teeth were randomly divided into two groups one of which had the smear layer removed by 5 ml of 5% NaOCl followed by 2.5 ml of 17% EDTA. Obturation was performed using AH Plus sealer and Thermafil. Specimens were cleared in methyl salicylate and analyzed under a stereomicroscope to evaluate the number, length, and diameter of lateral channels. All lateral channels were found to be filled in both groups. No statistically significant differences regarding number, length, and diameter were observed between the two groups. It was concluded that the smear layer did not prevent the sealing of lateral channels.

Yildirim et al. (2008) investigated the effect of the smear layer on apical microleakage in teeth obturated with MTA. Fifty single-rooted central maxillary teeth were used in this study. The selected teeth were instrumented and randomly divided into 2 groups. In the first group (smear [+]), the teeth were irrigated with only 5.25% NaOCl. In the second group (smear [-]), the teeth were irrigated with EDTA (17%) and NaOCl (5.25%) to remove the smear layer. The teeth were then filled with MTA. The computerized fluid filtration method was used for evaluation of apical microleakage. The quantitative apical leakage of each tooth was measured after 2, 30, and 180 days. It was found that there was no difference between the groups after 2 days but removal of the smear layer caused significantly more apical microleakage than when the smear layer was left intact after 30 and 180 days. It was concluded that the apical microleakage of MTA is less when the smear layer is present than when it is absent.

Saleh et al. (2008) studied the effect of the smear layer on the penetration of bacteria along different root canal filling materials. A total of 110 human root segments were instrumented to size 80 under irrigation with 1% sodium hypochlorite. Half of the roots were irrigated with a 5-mL rinse of 17% EDTA to remove the smear layer. Roots were filled with gutta-percha (GP) and AH Plus sealer (AH), GP and Apexit sealer (AP), or RealSeal cones and sealer (RS). Following storage in humid conditions at 37 degrees C for 7 days, the specimens were mounted into a bacterial leakage test model for 135 days. Survival analyses were performed to calculate the median time of leakage and log-rank test was used for pairwise comparisons of groups. Selected specimens were longitudinally sectioned and inspected by scanning electron microscopy for the presence of bacteria at the interfaces. In the presence of the smear layer, RS and AP leaked significantly more slowly than in its absence. In the absence of the smear layer, AH leaked significantly more slowly than RS. It was concluded that removal of the smear layer did not impair bacterial penetration along root canal fillings. A comparison of the sealers revealed no difference except that AH performed better than RS in the absence of the smear layer.

Fachin et al.(2009) evaluated whether smear layer removal has any influence on the filling of the root canal system, by examining the obturation of lateral canals, secondary canals and apical deltas. Eighty canines were randomly divided into two groups, according to their irrigation regimen. Both groups were irrigated with 1% NaOCl during canal shaping, but only the teeth in Group II received a final irrigation with 17% EDTA for smear layer removal. The root canals were obturated with lateral condensation of gutta-percha and the specimens were cleared, allowing for observation under the microscope. The results showed that In Groups I and II, 42.5% and 37.5% of the teeth, respectively, presented at least one filled canal ramification. In conclusion, smear layer removal under the conditions tested in this study did not affect the obturation of root canal ramifications when lateral condensation of gutta-percha was the technique used for root canal filling.

Bumblefoot is a common infection for domesticated poultry and waterfowl such as chickens, ducks and quail. Due to constant walking on hard, rough, or sharp surfaces, birds can develop small wounds on the bottom of their feet. These wounds are very susceptible to infection by opportunistic bacterial pathogens, chiefly "Staphylococcus aureus". Treatment often requires opening the wound to drain the pus, soaking it in epsom salts, and antibiotic treatment and local application of the antiseptic pyodine as local dressing.

Bumblefoot is so named because of the characteristic "bumbles" or lesions, as well as swelling of the foot pad, symptomatic of an infection. Topical antiseptics in addition to oral or injected antibiotics may be used to combat the infection, which if left untreated may be fatal.

Control of Leucostoma Canker is possible through a combination of pest and crop management techniques following life cycles of the trees. The strategy is implemented following techniques aimed at reducing number of pathogenic inoculum, minimizing dead or injured tissues to prevent infection, and improving tree health to improve rapid wound healing. Chemical controls have not been very effective at controlling this disease with no fungicides registered specifically for control of "Leucostoma" spp., and demethylation-inhibiting (DMI) fungicides having almost no effect on "L. persoonii".

Eyespot is an important fungal disease of wheat caused by the necrotrophic fungus Tapesia yallundae (syn: "Pseudocercosporella herpotrichoides"; W-type [anamorph]; "Oculimacula yallundae") and Tapesia acuformis (syn: "Pseudocercosporella herpotrichoides"; R-type [anamorph]; "Oculimacula acuformis"). It is also called Strawbreaker. Eyespot is more severe where wheat is grown continuously and when the weather is cool and moist. Treating crops against eyespot with fungicide costs millions to farmers and is complicated by the pathogen becoming resistant to the more commonly used fungicides. Severe cases of the disease can reduce yield by up to 40%. It is most common in temperate regions such as North and South America, Europe, Australia, New Zealand and Africa.

The most widely used potassium fertilizer is potassium chloride (muriate of potash). Other inorganic potassium fertilizers include potassium nitrate, potassium sulfate, and monopotassium phosphate. Potassium-rich treatments suitable for organic farming include feeding with home-made comfrey liquid, adding seaweed meal, composted bracken, and compost rich in decayed banana peels. Wood ash also has high potassium content. Adequate moisture is necessary for effective potassium uptake; low soil water reduces K uptake by plant roots. Liming acidic soils can increase potassium retention in some soils by reducing leaching; practices that increase soil organic matter can also increase potassium retention.