Lime vs. Gypsum – Is Gypsum The Same As Lime?
Author/Reviewed By: Josh Miller, Sales Manager: Baker Lime & North America Minerals
Published 1/05/2022 Updated 10/25/2023
Lime and gypsum for soil can both work to improve the health of your soil, but they work in different ways. Before deciding which is best for your fields, lawn, or garden, it’s important to understand what lime and gypsum are, how they work and how they differ from each other. It’s also important to understand your soil so you can choose the best option for its health.
What Is Gypsum & What Does Gypsum Do For Soil?
Gypsum is also known as calcium sulfate (CaSO4). It’s a natural element that provides sulfur and calcium to soil.
Gypsum for lawns comes from sedimentary rock and is formed by the evaporation of water that contains sulfates and calcium, such as saltwater. When the water evaporates, the minerals are left behind. Over time, they condense and form gypsum.
Common Gypsum Questions
What Is Gypsum Used For?
Gypsum has many uses, but one of its primary uses is in lawncare and agriculture. Farmers, gardeners and homeowners can use gypsum for soil to improve the health of their farmland, gardens and lawns. How conservatively do you have to use it, and what are the benefits and the drawbacks?
Can You Use Too Much Gypsum For Soil?
It is possible to use too much gypsum. Adding too much gypsum to your soil can damage it by removing necessary nutrients. An abundance of gypsum can remove elements such as iron, aluminum and manganese from your soil and cause them to contaminate other areas, harming plant growth.
Before applying gypsum to your soil, you should perform a soil analysis to determine if the soil truly needs it. Some types of soil, such as soil in coastal environments, need gypsum to reduce salt levels. Other soil types with lower sodium levels can suffer salt deprivation if you spread too much gypsum.
It’s important to avoid over-application of gypsum, but in most cases, you can apply 40 pounds of gypsum to every thousand square feet of soil at any time of the year. That number will be a little lower — about 20 to 30 pounds per every thousand square feet — if you plan to plant flowers, shrubs or vegetables. Once you apply the gypsum, you can wait three years to apply it again.
What Are the Benefits of Gypsum For Lawns?
Using gypsum for soil can improve soil structure, decrease soil compaction, decrease acidity, prevent water run-off, increase airflow and dislodge salt. It is a source of calcium and sulfur, which are essential for healthy plant growth. It’s natural and non-toxic, so it’s pet-safe and safe for you to handle without protective equipment like masks or gloves.
Gypsum contains calcium, which helps to improve soil structure. It aids in the flocculation process, which groups soil particles into clusters and improves air and water movement through the soil for healthy root growth.
Ice-melting chemicals such as salt damage lawns because they displace other elements necessary to a lawn’s health. Salt can prevent plants from absorbing the water they need and create drought-like effects in a lawn even when significant moisture is present. Gypsum can help to leach salt from the soil. Leaching is a process that uses water to drain salt from the root layer of a lawn to deeper layers of soil that do not interfere with plant growth.
Gypsum supplies calcium to the soil. The calcium displaces sodium so it can be leached with rainfall or irrigation water. The best way to use gypsum for the leaching process is to apply it after lawn aeration. Aeration creates small holes that make it easier for gypsum to enter and work within the soil.
Gypsum can also neutralize your lawn when pet urine threatens its health. Pet urine can damage your lawn and produce an unpleasant odor, but gypsum can resolve these issues by neutralizing the mineral salts in urine.
What Are the Cons of Gypsum For Soil?
While gypsum can effectively remove salt from your soil, it can also remove essential nutrients such as manganese, aluminum and iron. Gypsum can remove these nutrients during the salt-leaching process, leading to deficiencies that threaten plant and lawn health. Gypsum can add calcium to soil quicker than lime does, decreasing the levels of magnesium and potassium.
Another downside to using gypsum for soil is that it works slowly. After application, it takes many growing seasons to see total soil improvement.
Gypsum cannot adjust soil pH as lime does. In addition, you may harm your plants if you apply gypsum when the soil pH is too low. If the pH level of your soil is lower than 5, gypsum can damage your plants.
Lime vs. Gypsum For Lawns
Lime and gypsum both work to add calcium to your soil. Gypsum can also remove sodium and add sulfur to soil, but it can’t balance pH levels like lime can. Both gypsum and lime can help improve various nutrient levels that can damage your garden or lawn, but it’s important to understand your soil before deciding which is best for its health.
Should I Use Lime or Gypsum For Soil?
When determining if you should use lime or gypsum, it’s crucial to test the pH levels of your soil.
Measuring the pH level will help you determine if you should apply gypsum to your soil and how much you should use. If the pH level is less than seven, the soil is acidic. If the pH level is higher than seven, the soil is alkaline. If your soil’s pH is under seven, lime can help balance the pH levels and make your soil less acidic.
Gypsum can add calcium and sulfur to your soil while removing sodium, but it can’t increase the pH of your soil.
Leaching, erosion and decomposition can cause high soil acidity, significantly damaging plants and crops. Adding lime to your soil can reduce its acidity, allowing it to produce healthy crops and plant growth.
Can You Apply Lime and Gypsum To Soil at the Same Time?
You can apply lime and gypsum at the same time to improve the health of your lawn. Lime is water-insoluble, which means that it has low mobility in soil and can cause the surface level of the soil to harden, preventing water from entering deeper levels. Gypsum is water-soluble, so it has greater mobility and can help lime better infiltrate the soil.
Improve Your Soil With the Right Lime Products
Lime works effectively to balance the pH level of your soil. We provide high-quality limestone products that improve the health of your soil and keep your grass, plants or crops growing strong. Find your local Baker Lime distributor or contact Baker Lime to learn more about how our products can help you keep your lawn, garden or farm healthy.
