Skip to Content

How Much Lime to Apply Per Acre (And When to Apply It)

How Much Lime to Apply Per Acre (And When to Apply It)

Share this post:

This post may contain affiliate links. If you click an affiliate link and make a purchase, I may earn a commission. Also, as an Amazon Associate I earn from qualifying purchases.

So, you’ve tested your soil pH and found it more acidic than you’d like it to be, right? Well, this is where limestone comes in handy. Lime, or calcium carbonate, works its magic by neutralizing soil acidity and getting things back to normal.

But liming itself isn’t exactly a walk in the park. Overdo it, and you’ll only be hurting the soil quality.

So, how much lime should you apply per acre? And when is the best time to do so?

The short answer is you’ll need 1.2 tons of agricultural lime per acre to pump up the pH of loam soil by one point, ideally around spring or fall. Of course, things are a bit more nuanced than that.

Don’t worry, though. In this article, I’ll answer all your questions regarding limestone, its types, and how to apply it like a pro!

Liming Basics: Why Bother Using (and Measuring) Lime?

Kentucky Bluegrass Sod

Before diving into the details, I want to cover why it might be handy to use the exact right amount of lime in the first place.

If you’re already familiar with the benefits of liming, feel free to skip to the next section.

Getting Closer to the “Ideal” pH

For most types of grass, the ideal pH level for your soil is between 5.8 and 7.0, which is slightly acidic. However, that doesn’t apply to all types of grass.

For example, warm-season grasses prefer a more acidic (lower) pH. Since you’re here, I assume that’s not the case at all.

But Kentucky bluegrass, ryegrass, and fescues are cool-season grasses and do better with slightly higher pH.

Balancing the Soil Nutrients

As it happens, soil pH affects the nutrient availability. Some nutrients are more readily available in low pH levels and vice versa.

But if you leave your soil acidic, odds are, magnesium, potassium, phosphorus, and calcium levels will start going downhill. Unfortunately, this means your grass won’t grow properly.

Luckily, lime takes the pH closer to the neutral range, so your plants can have a balanced mixture of nutrients.

Plus, some manufacturers actually sell pellets that contain lime with nutrients/micronutrients. But I’ll go over the different types and how to choose the right one in a minute!

Understanding the Risks of Over-Liming

Just because acidity might be bad for your plants doesn’t mean it’s okay to go overboard with the lime.

In fact, you’ll be depriving your plants of trace elements like iron and manganese if you do.

As a result, you’ll start seeing pale spots that start at the leaf edges and take over the midvein area—that would be lime-induced chlorosis.

You might be able to salvage the soil with some sulfur or organic matter (like conifer needles), but that’s a hassle.

So, hopefully, you’ll be able to get the amount right from the get-go.

How to Calculate the Right Lime Amount

Now that you know why your soil needs a specific dose of lime, let’s see how you can figure out what this “dose” should look like.

1. Test Your Soil pH Level (Or Get Experts to Do It for You)

The first thing you need to do is test your soil pH level. Don’t worry, as it’s easier than you think!

You can buy do-it-yourself soil test kits or soil pH meters. The problem is that these tools won’t tell you how much lime your soil needs. You’ll have to calculate the amount based on the difference between the ideal and current ranges.

Alternatively, you can take the easy way out.

Most state or county cooperative extension agencies come out and test your pH. Then, they analyze your soil to recommend how much lime you should apply.

Not only do you receive accurate test results, but it’s helpful to have advice from experts!

2. Do the Math Based on Acreage and pH Difference

If you didn’t ask for help from the expert agencies, you’ll want to do the math yourself.

In general, it takes 1.2 tons of agricultural lime per acre to raise the pH of the loam soil by one point. On the contrary, you might use around half that value for sandy soil and almost double for clay soil.

I’d say that 1.2 tons of lime is the equivalent of 48 standard 50-pound bags of ground agricultural limestone.

It’s worth noting that the test will likely give you a recommendation in pure calcium carbonate.

So, you’ll want to look at the bag label to find the calcium carbonate equivalent. Then, you can divide the requirement (from the test results) by the equivalent value.

3. Factor in the Plow Depth

Usually, you’d plow the lime in with around 5–6 inches of soil. But if you go deeper for one reason or the other, you’ll need to use even more lime.

Thankfully, there’s a way to calculate the adjusted amount.

The Department of Agriculture at the University of Minnesota recommends using a factor of 0.17 plus one for depths greater than 6 inches.

For instance, if you plow 9 inches, you’ll want to multiply the depth difference (3 inches) by 0.17 and add one. This would leave you with a value of around 1.5.

Now, take this 1.5 and multiply it by the recommended agricultural lime amount per acre.

4. Split Larger Portions Into Two

You won’t always be able to dump the whole amount in one go.

If your soil needs more than 50 pounds of lime per 1000 square feet, it would be best to apply half in the spring and half in the fall.

Liming Best Practices: How and When to Apply Lime

By now, you should have a better idea about how much lime your soil needs.

But before you rush in and start mixing in the lime, let’s first check out some tips to make the most out of the treatment.

The Best Time to Lime

Mixing Dolomitic Limestone Powder Into Garden Soil

It can take several months for lime to break down and change the pH level of your soil. 

With that in mind, the best time to test your soil is in the spring, just as the soil begins to get warm. You can apply lime at this time or during the fall.

The reason why I recommend the fall is that the cycle of freezing and thawing, along with plenty of rain and snow, can be quite beneficial. They’ll help break down the lime.

Choosing the Best Type of Lime

There are different types of lime, and they all have the same goal of raising the pH of the soil to the neutral range so that the nutrients in the soil will be available to your plants and grass.

However, some are more convenient than others.

Here are the three most popular types of limestone:

  • Ag Lime: This type of lime is best for agricultural uses rather than a garden. It’s coarse, so it takes a long time to break down.
  • Pulverized Lime: This powder is made by crushing limestone rock. As a result, it breaks down quickly and raises the pH level in no time. However, it tends to be dusty and difficult to transport.
  • Pelletized Lime: To solve the transportation problem of pulverized lime, some brands make a pelletized form. There are also enhanced forms of pelletized lime with added polymers, organic acids, and micronutrients.

All in all, if you’re looking for an easy and fast solution, I’d recommend going for pelletized lime.

Liquid vs. Dry Lime

Liquid lime is used for industrial applications. Think sides of roads or golf courses. Its form makes it more convenient for spreading across large areas, but it doesn’t necessarily give the soil exactly the amount of lime it needs.

On the other hand, I find dry lime more reliable and easier to distribute evenly.

Calcitic vs. Dolomitic Lime

There’s one more way to classify calcium. This time, it’s by the chemical composition rather than the form.

Calcitic lime has calcium, as the name suggests. So, it’s generally better for the lawn because calcium benefits plants.

Still, dolomitic lime is a good option for a soil that lacks magnesium.

The Best Way to Apply Lime

Core Aeration Of Warm-Season Turf With Ride On Aerator

The first application tip to keep in mind is that lime should only be applied to a dry lawn. The second? The lawn should not be dormant or stressed.

Naturally, it’ll be easier to change the pH before you plant grass seed or lay the sod. So, if that is possible, mix the limestone with the top five inches of the soil. By doing that, you may not need to add lime again for several years.

But suppose you want to add lime to an existing lawn. In this case, you’ll need to aerate the lawn with a core aerator. Then, you can use a rotary spreader to apply the limestone to your yard.

Pro tip: You should cross the yard in perpendicular directions to ensure it’s entirely treated with lime!

Once you apply the lime, be sure that you water your lawn to remove excess particles from the grass.

The Golden Key: Regular Testing

Healthy Lawn With Lawnmower In Background

After several months, I’d highly recommend that you test your soil again. If the pH is where it needs to be, you won’t have to do anything else. Otherwise, you might need to add more lime.

Once you get the pH level of your soil where it should be, you can check it once every year or two to make sure that it’s staying within range.

Remember: Always test your soil before adding limestone!

Final Thoughts

You can always use a DIY kit to figure out how much lime to apply per acre.

However, the easiest way is to send a sample over to your cooperative extension agency. In this case, you’ll just need to check the calcium carbonate equivalent on the bag of lime you’ll use.

Just stick to the recommended amounts. Too much alkalinity can backfire!


If you want more backyard tips including recipes, how-tos and more, make sure you subscribe to my youtube channel

Share this post: