How to Lower pH in Soil

You can lower the pH of the soil by adding things like elemental sulfur, aluminum sulfate, and iron sulfate that you can buy, or you can use natural soil acidifiers like peat moss and compost.

Is your soil’s pH too high? Do you know that when the pH of the earth is high, it makes too much of some nutrients that are bad for plants?

The pH of sand tells you how acidic or basic it is by measuring how many hydrogen ions are present. The pH scale goes from 0 to 14, with 7 being neutral. 

If the pH is less than 7, the soil is acidic. If it is above 7, the soil is alkaline. “Master soil variable” or “soil reaction” are other names for pH.

What Is pH?

How to Lower pH in Soil

In simple words, pH tells you how acidic or basic a substance is. It goes from 0 to 14. The lower the number, the more acidic the material is, and the higher the number, the more alkaline it is.

A pH of 7.0 is thought to be normal. An acidic substance is one that is less than 7.0 on the pH scale. An alkaline substance is one that is greater than 7.0 on the pH scale.

PH measures the number of free hydrogen ions in the solution. This is how the number is found. It is more acidic when there are more hydrogen ions than when there are not.

It’s important to remember that when the pH level changes, it goes up or down by a number of 10. This is shown in the image below. What this means is that a difference of 1 unit is not as important as a difference between pH 5 and 4.

pOH is another thing you might see when you look at pH tools. This is kind of like pH, but it measures the amount of OH ions present. It works the other way around, with low numbers meaning the substance is alkaline and high numbers meaning it is acidic. This is a less important number, but it might come up when you look at acidity and alkalinity.

How To Test Your Soil

A small fee will be charged by your cooperative extension office to do a basic test on soil from your yard. The results show the pH level as well as the main and secondary nutrients and micronutrients that your sample may not have enough of.

You can also buy a test kit in stores, online, or at garden centers. For a simpler test, you can use things you already have in your house.

When To Lower Soil pH

If you want to make a new flower bed, you should test the soil as soon as possible. Soil bacteria react with sulfur to lower the pH, but the soil has to be above 55 degrees Fahrenheit for this to work. After adding sulfur, you should wait about a month before planting. Adding sulfur in the fall or winter won’t work as planned.

Before you plant, it’s also easiest and most effective to change the way the soil is made up. Even though this isn’t always possible, be sure to use the best tools and methods to keep the roots from getting hurt.

NOTE: When dealing with chemicals, you should always be careful. Gloves, safety glasses, and protective clothes can keep your hands and eyes from getting burned or irritated in other ways.

Decreasing The pH In Soil

What you use to lower the pH of soil varies on the type or size of plant you are growing and how quickly you want the pH to change.

Adding elements like sulfur, aluminum sulfate, and iron sulfate that can be bought in stores is the best way to lower the pH of soil.

Elemental Sulfur

Most people use elemental sulfur to lower the pH of their soil because it is safe, not too expensive, and easy to find at most garden stores and agriculture suppliers in their area. One bad thing about it is that it takes a long time to react with soil. Elements of sulfur need to go through two steps in order to lower the pH of soil: a slow organic process and a fast chemical process. It might take 3 to 6 months to finish this process.

Aluminum Sulfate

On the other hand, aluminum sulfate reacts with soil very quickly because it only needs to finish the chemical process. Two bad things about using aluminum sulfate are that it is harmful to plants and a lot of it is needed to lower the pH.

Iron Sulfate

Iron sulfate, also known as ferrous sulfate, reacts quickly in soil. It costs more than basic sulfur because it takes eight times as much of it to lower the pH in soil. Soil’s pH drops when iron sulfate breaks apart the salts into iron and sulfuric acid. This binds iron to clay or precipitates, which neutralizes the soil.

Because aluminum sulfate and elemental sulfur are stronger ways to lower the pH of soil, you must use the right amounts.

You can also lower the pH of your soil over time by adding things like peat moss, rotted manure, or organic leaf compost. If your land is sandy, peat moss will work especially well.

How To Lower pH Naturally

Using natural materials to lower the pH takes time and needs to be done more than once, but it is one of the easiest ways to do it in flowerbeds and gardens that are already there.

Organic materials like manure and compost can be added to vegetable fields before they are planted or as side dressings that are raked or hoed in after the plants have grown.

But all types of manure should be aged before they are put to garden soil. Chicken manure works best for making soil more acidic. Mulches, bark, and leaves made from pine all lower pH but break down very slowly.

How To Lower pH After Planting

Over time, the soil loses its acidity, which makes the pH level grow. Keep the best balance for plants is a constant process because of this. Ammonium nitrate works quickly, but it also runs out quickly, so it needs to be used again and again.

When added to the soil around plants, it needs to be worked in. Adding too much can hurt the roots and their ability to take in nutrients. Adding organic mulches and well-composted material every year is the best way to keep the pH level of your flowers, fruits, and veggies at a neutral level.

What Can Affect Soil pH?

Because soil was made from rocks, its natural pH is set by those rocks. It is also changed by time, vegetation, dry or wet climates, and the land’s shape. As time goes on, nitrogen fertilizers with ammonium and ammonium sulfate in them lower the pH.

A slow drop in pH can also happen with some organic fertilizers. Hard water has minerals and salts that raise the pH of the earth. A lot of wood ash also does this.

Factors Affecting Soil pH

The types of parent materials that a soil was made from affect its pH value. Most of the time, soils that formed from basic rocks have higher pH levels than soils that formed from acid rocks.

Soil pH is also changed by rain. Basic nutrients like calcium and magnesium are washed out of the soil when water flows through it. They are swapped out for acidic elements like iron and aluminum.

Because of this, soils that formed when it rained a lot are more acidic than soils that formed when it was dry.

Using nutrients with ammonium or urea speeds up the process of soil becoming acidic. Soil becomes more acidic when organic matter breaks down.

Frequently Asked Questions

Q: What Fertilizer Will Lower pH Of Soil?

A: Soil pH will go down when you use ammonium and sulfur fertilizers. Some of these nutrients are urea, ammonium sulfate, and ammonium nitrate. Nitrogen fertilizers, on the other hand, will make the soil more acidic.

Q: Can You Use Vinegar To Lower pH In Soil?

A: Even though vinegar is acidic, it doesn’t work as well as the other methods in this piece.

Q: Why Is My Soil pH So High?

A: There are a few reasons to explain this. One could be just the place where you live. Soils that don’t get as much water and have more sand naturally have a higher pH. The constant use of wood ash and alkaline supplements could be another reason.