Gypsum Lawn Treatments: Improving Soil Structure

How Gypsum Treatments Can Improve Lawn Soil Structure

Do you have a lawn that isn't looking so healthy, with a lack of greenness or unsightly patches of burnt grass? Your lawn's poor appearance could be an indication of additional problems under the surface, in the soil. One aspect of having a healthy lawn is good soil structure. Gypsum is a mineral that can amend heavy clay-like soils, enhancing drainage and root penetration. We'll walk you through how you can utilize gypsum treatments to improve your lawn.

Benefits of Using Gypsum

Gypsum is non-toxic and does not increase the pH level of your soil. Given the moniker of 'clay breaker,' gypsum is a mineral composed of calcium sulfate (CaSO₄). To explain why it's called by that name, we’ll dive into a bit of science here.

Soil structure hinges on the exchangeability of positively charged ions between soil particles. Particles with more than one positive charge (multivalent cations) help hold soil particles together due to their electrostatic attraction between two or more negative charge sites. Particles with only one positive charge (monovalent cations) degrade soil structure when large amounts of these particles occupy the icon exchange sites. Sodium (Na) is a monovalent cation, and due to its large particle size, it can seriously affect soil health if there are high amounts of it in the ground.

Gypsum helps break up excess sodium in soils, as this mineral's calcium (Ca) ions displace the sodium (Na) ions from the exchange sites. Once disturbed, water flushes the salts and Na from the soil. The soils that have this issue are clay-heavy soils and sodium-rich sodic soils. Found in more arid regions of the world, sodic soils can benefit from gypsum treatments. By improving the soil structure, you can have better water infiltration and root penetration. Other benefits that the dissolved gypsum provides to your lawn include adding more sulfur to the soil for your grass to uptake, giving it that lush green look.

Sometimes, vital nutrients needed by your lawn (e.g., iron) are present but held tightly to the clay particles due to the soil's high pH level. When you apply gypsum to your lawn, the sulfur in the mineral works to free-up the tightly held nutrients, making them available for your grass to utilize. High pH soils are commonly found in urban areas due to human factors such as construction runoff, and municipal water sources containing bicarbonates which can raise the soil pH through watering.

While gypsum mainly benefits sodic soils, it can help lawns recover from regions that use rock salt or ice-melt chemicals throughout winter. These salts can find their way into the lawn and cause problems for yards when springtime rolls around. The excessive salt that goes into the soil can displace other vital nutrients in the ground. Gypsum treatments allow the salt to leach into the soil below the grass roots.

How to Apply Gypsum On Your Lawn

To determine if your soil could benefit from a gypsum treatment, consider getting your soil tested. Reach out to your local university extension office or work with an agronomic firm about getting soil samples collected and analyzed from your lawn. If your tests come back showing high sodium levels, low levels of calcium, or that your soil is heavy with compacted clay, you could be a candidate for using a gypsum treatment on your yard.

When figuring out how much gypsum to apply to your lawn, consider using the following recommendations:

• For established lawns, use 40 lbs. per 1,000 sq. ft.
• For new lawns with heavy clay, use 300 lbs. per 1,000 sq. ft.

You can apply gypsum on your lawn two to three times per year; it doesn't matter what time of year you spread the treatment. To disperse the gypsum, use either a drop or broadcast spreader. Water the lawn immediately once you’ve finished the application.

For more information about lawn care, nutrients, and more, visit Natural-Fertilizer.com.