Which Fertilizer Increases The Acidity Of Soil? – And How To Use Them

For gardeners and lawn owners, checking their soil before they plant anything is very crucial, and then making the soil suitable. And to make the soil suitable there is one thing you need to keep in mind and that is soil pH level. The pH level is very important for growing anything in your backyard.

Sometimes you need to grow a plant that loves acidic soil but unfortunately, your backyard is alkaline and you need to increase the soil acidity. So which fertilizer increases the acidity of the soil?

Fertilizers containing ammonium nitrate, ammonium sulfate, or sulfur-coated urea can increase the acidity of the soil very quickly. So just look for Ammonium-based fertilizers on the pack. If you take a nitrogen-rich fertilizer then it is certain that one of these 3 is included in that fertilizer to increase the soil acidity.

Let’s look further at what pH level and soil acidity are and whether it is good or bad for the soil.

What is the pH level?

Soil pH is crucial for soil health and to grow plants in it. What soil pH does is measure the alkalinity or acidity levels of the soil. The pH level is in the range between 0 to 14 scale, where 0 to 7 is considered to be acidic and 7 to 14 is considered alkaline, and 7 is considered to be neutral.

The changes in the pH level of the soil occur when certain types of nutrients are added or removed from the soil with the help of chemicals or plantations or by leaching of nutrients. These occurrences can make the soil more acidic or more alkaline which then can cause some issues. 

What is soil acidity? 

Soil acidity or soil acidification is a natural process when leaching happens slowly in a high rainfall area. Soil also becomes acidic when intensive agriculture happens and it can increase leaching in the soil. 

Adding chemicals like ammonium sulfate-based fertilizer is also a reason for soil becomes acidic. But the most common reason for soil becoming acidic is nitrogen. Different types of nitrogen can affect the soil differently and make it more or less acidic. 

Is soil acidity good or bad for the lawn?

Most gardens and lawns prefer slightly acidic soil to grow as acidic soil helps the plants to take up nutrients very easily. So it can be said that having acidic soil is good for the plants. But maintaining a pH level around 5.5 to 6.5 is recommended as going below that is also not good for the plants when the lawn is too acidic and will not be able to help the plant to take nutrients very easily from the soil.

Which fertilizer increases the acidity of the soil? 

All nitrogen fertilizers have their chemical composition to provide nutrients to the soil. These fertilizers have different pathways as they break down in the soil and release different amounts of hydrogen ions to the soil. 

Ammonium-based fertilizers are the most common and widely available fertilizer which increases the acidity of the soil. All the nitrogen these fertilizers provide to the soil can’ be taken up and absorbed by the plants and due to that, it begins to leach.

Some of this ammonium fertilizer also makes the soil acidic if the nitrogen is taken up by the plants. So ammonium nitrate and ammonium sulfate fertilizers are the ones that increase the soil acidity. 

List of acidic fertilizers to increase soil acidity

  • Ironite plus plant food 12-10-10
  • Pennington epsom salt
  • Coffee ground fertilizer 
  • Eggshell fertilizer 
  • Fish manure fertilizer 
  • Compost fertilizer 

How to increase the acidity of the soil?

There are many ways of increasing the acidity of the soil, some are organic and some are synthetic. 

  • Using sphagnum peat – adding a layer of sphagnum peat to the soil is a good way to increase the acidity of the soil quickly. Add 1 to 1.5-inch layer of peat to the soil and water it thoroughly. 
  • Vinegar – adding vinegar to the soil is also a very good way to increase the acidity of the soil. Add 1 small cup of vinegar to 1 gallon of water and then apply this to the soil. This method increases the soil acidity quickly and very effectively without having any negative effect. Just don’t add too much vinegar and don’t over water an area.
  • Acidic fertilizer – using an ammonium-based fertilizer in your lawn is also good for increasing the acidity of the soil. Ammonium nitrate and ammonium sulfate are very effective in providing nutrients and increasing the acidity of the soil.
  • Add sulfur – adding sulfur to your alkaline lawn can also be a very safe way to increase the acidity of the soil. Sulfur increases the acidity of the soil very slowly over several weeks. Add chips or dust to the soil and water it thoroughly. The effectiveness of sulfur depends on what type of soil you have. If it is clay soil then it will require more sulfur to increase the soil acidity and much more time than in sandy soil.

How to decrease the acidity of the soil? 

So if you have tested your soil and found out that the soil is too acidic and want to increase the pH level of the soil. The best way to do this is by adding garden lime into the soil. Garden lime helps the soil to become less acidic slowly and restore the pH of the soil. An idol of the soil should be in between 5.5 to 7

There are several types of garden limes available, and all are good in restoring the pH level. Read the label properly and add the suggested amount of lime in the soil and then after that water it thoroughly so that the lime can go into the soil and start the process. 

How do you increase soil acidity organically?

Increasing the acidity of the soil organically is very easy. Adding vinegar into the water and then applying it into the soil or using organic compost or homemade compost can increase the acidity of the soil. Just the downside of organically doing it is it takes time to change the pH level of the soil and you need to wait a long time before it shows results.