Now Is Not the Right Time to Treat Plants With Animal Manure.
For years, gardeners and farmers have used one of the world’s richest resources to produce fertilizer: animal feces. Animal manure is generally free and easy to obtain from both your own animals and those of others.
Collecting livestock waste to make fertilizer is generally considered a safe practice: Most manure is composted before being applied to the ground, meaning it has undergone a period of heat treatment that reduces the risk of contamination.
However, there are a number of ongoing health considerations and cautions worth keeping in mind when using bat manure at home, including two deaths associated with the collection of bat manure at home. With ongoing outbreaks of H5N1 avian influenza, it is definitely time to be cautious when feeding your plants.
Manure is usually an excellent source of free fertilizer.
While the idea of collecting poop may seem strange to non-gardeners, manure is a near-perfect fertilizer , provided it is managed properly. It’s full of nutrients consumed by the animals that produced it, and if they’re your animals, you know what went into that diet. Manure is also pretty darn organic and can be obtained for free in most cases.
Some manure is considered “cold”, that is, it can be used immediately without harm to plants (including feces of rabbits, ducks, goats). Some types of manure, including chicken, cow, and horse manure, can burn your plants if not handled correctly, which is why they are considered “hot.” By simply piling the manure into a pile, ensuring a good carbon to nitrogen ratio, and allowing the sun (and the composting process) to heat the pile, you will have recycled manure compost ideal for use as fertilizer. Many types of industrial fertilizers take into account the manure they contain.
Animal manure can carry diseases
The problem is that manure can also carry diseases, fungi and other pathogens. Some of these cells can be destroyed during the composting process, but not all. While the risk of transmitting these diseases to your fruits and vegetables is low, the risk to the person handling the manure is real. If you topically apply manure to plants, fruits or vegetables and do not wash it off well, it may remain on the surface.
Even some commercial fertilizers can pose health risks.
Recently, two men died in unrelated incidents after inhaling spores from bat droppings, which are believed to be particularly useful in cannabis production. In one case, an infected person manually collected guano from wild bats, and in the second, a patient applied commercially purchased guano to marijuana he was growing and smoking.
In most cases, fertilizers sold commercially are regulated and should be considered safe. However, in the United States, fertilizers are regulated at the state level, meaning that enforcement and regulations may vary depending on where the fertilizer was produced or sold. In the study of these deaths mentioned above, two scientists, Dr. Sudnik and Dr. Ted Louis, note that commercially sold bat guano fertilizers do not mention the health risk of histoplasmosis, which both men died from, and that great caution should be taken when their use.
The use of masks or respirators can generally protect gardeners from contamination from handling animal waste.
Avian influenza (H5N1) persists in chicken droppings
Much more common than bat manure, manure derived from the waste of chickens and other poultry is an incredibly common fertilizer, but it may be a concern at a time when much of the world is dealing with a highly pathogenic form of avian influenza (H5N1). . The virus has now been found in cows, pigs, domestic and large cats, and has also infected humans . If H5N1 is found in farmed birds, cows or pigs, the animals must be destroyed to stop the spread.
The main form of transmission of bird flu is bird droppings. Infected birds spread manure around other animals, which eat it and become infected, thereby infecting other animals nearby. Although large commercial farms are of greatest concern, backyard herds are also susceptible. Thus, handling bird droppings can be dangerous to humans, and since bird flu is highly pathogenic, it can remain in the manure even after composting if it does not reach a sufficient temperature for long enough.
Handling any manure without protection is a risk, so perhaps avoid it altogether.
“Given the current situation, I would not work with animal manure unless I was wearing the appropriate personal protective equipment,” said Dan Teich, DVM, a veterinarian and owner of District Veterinary Services in Washington, DC. “It’s an N95 mask or respirator [and] goggles and gloves, and I’ll be very careful after washing dishes.”
Or go cold turkey (no pun intended). While these threats continue, it is a good idea to consider not using backyard or farm manure in your garden. While commercial fertilizers should generally be safe, it is worth checking labels for instructions on safe use and considering only using fertilizers that have been processed and labeled as such. Consult your local garden center to find fertilizers that are suitable for your use and have been tested for safety.