Are pesticides water soluble? There are pesticides that are water-soluble but not all pesticides are water-soluble. Pesticides are made from different ingredients. It is these ingredients that determine whether it will dissolve in water or not. Like salt and sugar, there are some pesticides that will dissolve in water. You can come to this conclusion by putting some pesticides in water.
When you stir the mixture and the molecules bond with water molecules, then that is a soluble pesticide. Highly soluble pesticides can be easily absorbed by the roots of plants because they travel with water as it moves through the soil.
On the other hand, some pesticides are like oil. They don’t dissolve in water no matter how much you stir or heat the mixture. The ingredients found in such pesticides are insoluble with water.
Compared to soluble pesticides, insoluble ones can’t be easily absorbed by the roots. This is because, instead of moving with the water, these pesticides will stick to the soil. Most pesticide manufacturers indicate the solubility of their product on the package in mg/L.
So, the answer to this question is both yes and no.
The Characteristics of Pesticides
Getting the best pesticides for your plants requires more than just reading through the ingredients. Understanding the physical and chemical characteristics gives you an upper hand in making a more informed decision.
A lot of gardeners find it hard to get rid of pests even when they are using pesticides mostly because they do not pick a water-soluble product. Below are some of the characteristics of pesticides you should consider before buying some.
i. Solubility
We can define solubility as the measure of a pesticide’s ability to dissolve in water. As mentioned earlier, highly soluble pesticides dissolve in water faster and can easily move with the water to the plants’ roots. Pesticides that have a value of 10mg/L are relatively insoluble. Whereas those with a measure of 1,000 mg/L are very soluble.
In instances where manufacturers don’t indicate the solubility measure of their pesticides. They may use terms such as emulsifiable, dispersible, miscible and soluble.
ii. Adsorption
This term refers to the ability of a pesticide to bind with soil colloids. Glue-like microscopic organic and inorganic particles found in the soil are what we call colloids. Water-soluble pesticides have low adsorption compared to insoluble pesticides that adsorb tightly to the soil.
iii. Persistence
Another essential characteristic of pesticides that you need to learn about is persistence. It refers to the ability of the pesticide ingredients to remain active and in its original form for a longer period. Using pesticides with persistent half-life has its advantage and disadvantage. Yes, it will offer long term pest control and remove the need for frequent application but can later harm sensitive plants, animals and even human beings.
Therefore it is critical for you to consider the persistence of the pesticides you buy. This information is clearly labeled on the package of the pesticide. It is also important to understand the degradation process of every pesticide. Some breakdown through hydrolysis, others with the assistance of micro-organisms in the soil and finally, others are broken down by exposure to sunlight.
iv. Volatility
The tendency of a pesticide to turn into gas or vapor is known as volatility. It can be caused by temperature changes. And, pesticides that are very volatile are quite dangerous and can affect other plants nearby. Volatility is measured in mmHg and Pa.
Examples of Water Soluble Pesticides
Below is a list of the active ingredients found in pesticides that are soluble in water. We have listed them according to solubility value.
-
- Acephate (Orthene) – 790,000mg/L
- Dinotefuran (Safari) – 39,830mg/L
- Cyantraniliprole (Mainspring) – 14,200mg/L
- Flonicamid (Aria) – 5,200mg/L
- Thiamethoxam (Flagship) – 4,100mg/L
- Pymetrozine (Endeavor) – 290mg/L
- Spirotetramat (Kontos) – 29mg/L
Next time you are shopping for soluble pesticides, make sure you look for any of the above active ingredients.
How Can You Test Water for Pesticides?
One of the best practices for using pesticides is ensuring that it doesn’t permeate the ground and contaminate drinking water. If you own a private well or another source of drinking water, you should frequently taste for pesticide presence in the water. Drinking such water can lead to water poisoning.
Here are some kits you can use to test water for pesticides;
-
- PRO-LAB Pesticide in Water Test KitWATERCHECK TEST KIT (water check)
- Safe Home Ultimate Drinking Water Test Kit (amazon)
- Essieny Drinking water Test Strips (amazon)
- Varify Complete Water Test Kit (amazon)
Water Solubility Values and Definitions
Water solubility is measured in milligrams per liter that is the number of milligrams that will dissolve in one liter of water. For any pesticide with a rating of less than 10mg/L, it is categorized as low water solubility. Those ranging from 10 – 1,000 mg/L have moderate water solubility. If it exceeds more than 1,000mg/L then that is a highly soluble pesticide.
How Do Pesticides Affect Water Quality?
Pesticides though great at getting rid of pests in our plants. Excessive use affects our water quality. Soluble pesticides flow with the water in the soil and can reach groundwater. Most pesticides contain chemicals such as nitrogen, sulfur, bromine and some heavy metals like arsenic, mercury, and lead.
When these compounds find their way into water sources, it leads to contamination. And contaminated water can be poisonous for human and animal consumption. The first form of contamination starts when these compounds reach the groundwater. The contaminated water starts affecting marine life. For instance, if there is pesticide use near a river or lake, fish may start dying.
Treating contaminated water is very expensive. This is why it should be prevented instead of waiting to mitigate the problem. Sustainable use of pesticides is the only solution that can help us solve these issues.
Pesticides in Groundwater
Most pesticides that find themselves in groundwater are those that are applied directly to the soil and not sprayed on plants. The ingredients of these pesticides find their way into the groundwater through leaching and runoff. The latter mostly occurs over a running surface. The rate at which pesticides can reach groundwater depends on how closely the water table is in your location. Also, the more soluble a pesticide is, the easier it can get in groundwater.
How Do Pesticides Get into Water?
We have already described above how pesticides find their way into groundwater. However, there are other sources of water near our homes and if pesticides aren’t used correctly, they can get into that water and contaminate it.
Drains are one of the most common ways pesticides get into the water. When it rains, and there are traces of pesticides in your garden. That water is carried to the drain. And the drains direct it straight to the nearby river, stream or creek.
Wastewater treatment plans also act as another conduit of pesticides to get into the water. Most of these plants do not fully detoxify the chemicals and end up releasing them to rivers and streams. To avoid this, we must adopt the proper use and storage of pesticides.
What are the Effects of Pesticides?
As you try to combat a pest infestation on your plants, pesticides are often the number one go-to solution. However, improper use of these pesticides does more harm than good at times.
Pesticides have been known to pollute the environment for decades through leaching and volatilization. The chemicals might have adverse effects on the soil, crops, and animals.
Some ingredients found in pesticides have been linked to depleting the soil from its natural nutrients. Other chemicals are too strong for some plants.
Additionally, pesticides have been linked to several health complications amongst animals and humans. This includes cancer, Parkinson’s disease, Alzheimers and Asthma. For animals such as pets that come into contact with pesticides, they suffer from respiratory problems.
Due to all these possible effects, we are forced to adopt the best pesticide practices. This entails the use of natural pesticides in an orderly manner. Should you opt for synthetic pesticides, stick to trustworthy manufacturers only. Pesticides should be handled with care and kept away from food and water sources.
How to Prevent Pesticides from Getting into Water?
Now that you know about the dangers of pesticides getting into the water, here are tips on how to prevent such from happening.
-
- Always go through the label of any pesticide before you use it. Ensure that you understand its chemical and physical properties before applying it to your garden.
- Opt for pesticides that have a shorter shelf life, instead of those that can persist for long after being applied.
- Consider using pesticides that have an average solubility value. This will prevent the ingredients from flowing into groundwater.
- Never apply a pesticide when it is raining.
- Avoid using pesticides on sidewalks, driveways or anywhere that it can find its way into the drain.
- Ensure proper storage of pesticides. And if it’s time to dispose it, don’t flash it down sewer systems or storm drains.
Conclusion
In summary, we can conclude that there are pesticides that are soluble in water whereas others aren’t. Whether soluble or insoluble, each of these types does have its pros and cons. The soluble pesticides are great at dealing with pests because they can easily flow with water and can be absorbed by roots.
Insoluble pesticides find it harder to navigate their way into the soil, thus not as effective in getting rid of pests. The good news is, they can’t contaminate groundwater but can be washed away into dams, rivers, and creeks.
As a gardener, you should follow the best practices when using pesticides.
Let the above article guide you in ensuring you use pesticides in a way that is safe for the environment.