Skip to content

How to Add Lime to Acidic Soil

How to Add Lime to Acidic Soil

The type of soil you have in your garden plot significantly affects the growth and health of plants. Some of your plants might require alkaline or neutral soil, but you only have acidic soil. To address this problem, you have to know how to add lime to acidic soil. Lime is a soil amendment utilized by many homeowners to raise the pH level of their soil.

With that in mind, check out our guide on how a lime application should be done.

Assessing Your Soil

To determine how much lime should be applied to your soil, you must first conduct a soil test. You can do this on your own using a soil test kit, but the results won’t be comprehensive. In contrast, you will get a detailed analysis if you seek the help of a local county extension service or a laboratory specializing in soil tests. Apart from identifying how acidic or alkaline your soil is, you will also learn the amount of limestone necessary.

What’s the Correct Amount of Lime to Add?

Homeowners should remember that nearly all grass varieties will grow well if the soil pH ranges from 5.5 to 7.5. If your soil pH is much lower than even 5.5, you need to apply lime.

To put it in numbers, you’ll need a minimum of 20 pounds of ground limestone to adjust the pH of 1,000 square feet of your garden plot. If the soil is more acidic, you probably have to use 50 to 100 pounds of lime for the same area. Of course, the soil type also matters. For example, 1000 square feet of sandy loam soil should be applied with 50 pounds of ground limestone. As for loamy soil and heavy clay soil, they require 70 pounds and 80 pounds of lime per 1,000 square feet, respectively.

When’s the Best Time to Add Lime?

Adding lime to acidic soil can be done whenever you want. However, the ideal period is when you are preparing the soil. This way, you can prepare all the tools for improving the soil and plan ahead to stay efficient. Apart from applying lime, you can rake debris on the soil surface away, add a layer of mulch, and/or use other amendments to improve the health of your soil. Fall is a good time since it provides the soil many months to incorporate all of the lime. By spring, the soil should be ready for planting.

Mix the Lime with the Soil

Safety is always paramount to any activity, so you should wear a face mask before you apply lime to the garden. This should protect you from inhaling the dust of finely ground limestone. Take note of the amount of lime we previously mentioned depending on the type of soil in your garden.

Now, you need to apply half of the amount first. For example, if you have 50 pounds of ground limestone, only 25 of it should be initially used. Ensure that the limestone is mixed with the first 10 inches of the soil. Afterward, put the remaining 25 pounds on the soil surface. Once you water the ground, moisture will help to reduce the acidity in your soil.

Conduct Another Soil Test

The effects of the ground limestone won’t be observable overnight. In fact, it could take several months up to a year before the soil pH finally becomes stable again. After all, the lime needs to be wholly dissolved before you can determine the efficacy of the application. Thus, you should wait for at least two months before you check the pH level of your soil. By this time, there should be some minor changes in the soil pH.

If you think that it’s still too acidic, you can apply more lime. However, if you applied too much ground limestone, you can offset this by adding compost.

Overall, adding lime to the soil isn’t that difficult. What matters is you know the amount necessary depending on the total area, the soil type, and utilize the results provided by the soil test. Lastly, be patient since the changes don’t happen immediately. We hope that you learned a lot from our guide. If you have any questions, feel free to send us a comment.

Shop Probiotics for Your Garden

But, What Happens If There’s Too Much Lime In The Soil?

Too much lime in the soil can have adverse effects on land productivity. Surprisingly, the whole picture of the total impact of excess lime can be realized after three years. You can hardly notice it in the first year. The soil becomes so alkaline that plants are unable to utilize the nutrients available. Excess salts may also amass in the soil. Consequently, there is a stunted growth of plants and leaves turn yellow, a condition known as chlorosis.

Some soil samples have to be taken to a soil testing laboratory to establish whether the yellowing of leaves and poor growth is as a result of excess lime. The soil nutrient content and pH will then be tested and analyzed for a final report. The test is essential since some pests and diseases mimic symptoms of too much lime in the soil.

Effects of Too Much Lime on Soil pH

The pH helps to establish the alkalinity or acidity of the soil. The addition of lime in acidic soil raises its pH. Phosphate levels increase with increasing pH but can be tied up when the pH is too high. Lime is commonly used to increase the pH of acidic soil which contains insufficient phosphate to support healthy crops. Additionally, other elements such as zinc, manganese, iron, and copper can be tied up because of the increased pH.

Effects of Too Much Lime on Trace Elements

The ideal pH required for most plants to sufficiently take up nutrients from the soil is between 6.0 and 7.0. Plants experience a deficiency of manganese, iron, and other minerals when the pH is too high. Iron chlorosis, also called an iron deficiency, causes the leaves to turn white, yellow or pale green. The leaf edges may also appear scorched as a result. Lack of manganese in the soil turns older leaves yellow, with the central area being green. This deficiency also causes curled leaf edges.

Excess lime leads to the increase of the calcium level in the soil, and this causes magnesium, potassium, and other trace elements to tie up to the point that plants can no longer use them. Eventually, there is poor growth of crops, and the quality of yields is also affected.

Effects of Too Much Lime on Water Use

The application of calcium in the soil enhances the soil aeration by increasing the pore space. The result is bearable until the pore spaces exceed 50% of the total soil volume. Applying too much lime leads to the expansion of the pore spaces and distracts the soil’s water retention capacity. The increased water infiltration causes the soil to dry up quickly, leaving insufficient moisture for the crops.

The countermeasures that can be taken to reduce the effects of too much lime in the soil include treating the high pH using sulfur compounds like ammonium sulfate or just the elemental sulfur. Soil bacteria transform the latter to sulfuric acid, which in turn lowers the pH. Organic matter, such as peat moss or manure, can be used to counter the increased pH.