Gypsum vs. Lime: What’s the Difference?

Using Gypsum for Soil 

Gypsum is commercially available in granular or powder form, with some brands now offering it in a liquid suspension for ease of application, however LawnPride’s Granular Gypsum is typical of most Gypsum products on the market. It’s applied at between 5-10 kg per 100sq.m of lawn, spread over the surface of the lawn and then thoroughly watered in.

As well as its commonly-known applications as a clay breaker, the LawnPride team are quick to point out Gypsum’s two other uses – correcting calcium levels, and reducing crusting of the soil layer.

It’s common for home lawn owners to apply Gypsum at the start of Spring, coinciding with their annual lawn renovation in an effort to help combat clay in the soil, but also to assist with the uptake of any other fertilisers and supplements they’re applying at the same time.

Using Lime for Soil 

Much like Gypsum, Lime can be sourced as a granular, powder or suspended liquid supplement for use on home lawns, however a granular product like LawnPride’s Granular Lime is easy to source, spread and store.

It’s spread evenly over the lawn at between 5-10 kg per 100sq.m, before being watered in to do its best work in the soil layer.

We’ve mentioned how similar these two naturally-occurring lawn supplements are, but we can hone in on three important differences between Gypsum and Lime:

Functionality

Both minerals address issues with soil composition, however Gypsum is more concerned with what’s in the soil (namely, clay) whereas Lime is used to address soil acidity. Lime neutralises hydrogen ions whereas Gypsum merely displaces ions to address compaction.

Chemical Composition

Lime is a carbonate, oxide or hydroxide of Calcium which allows it to alter a soil’s pH, whereas Gypsum is merely a sulphate, allowing it to make sulphur more bioavailable in the soil (but not so much sulphur that it affects a soil’s pH).

pH Adjustment

Lime can be used to adjust a soil’s pH, whereas Gypsum cannot. While they both contain Calcium, the Calcium in the Gypsum isn’t enough to alter the soil to the point where it can raise a soil’s pH like Lime.

Best Soil Types for Gypsum

While it’s best known as a clay breaker and should definitely be used on clay-heavy soils to help change their composition over time, Gypsum is safe to use on all lawns thanks to its calcium-correcting properties and its ability to deposit sulphur to assist with the bioavailability of other nutrients.

Gypsum is safe for clay-based soils or those needing calcium, without altering the soil’s pH.

Best Soil Types for Lime

Lime on the other hand is best used in applications where a soil’s acidity needs to be brought under control. Like Gypsum, it can be used to make other nutrients more available for overall soil and plant health, but you should know your soil’s pH range before applying Lime because of the effect it can have on this delicate balance.

Because they have vastly different functions it’s difficult to rate which is more effective, but in terms of timeliness, Lime can change a soil’s pH much quicker than Gypsum can break down clay, so in that sense Lime is a more effective nutrient.

The fact that they can be used together (pending a soil test to determine pH) makes them both extremely versatile.

By using Gypsum and Lime appropriately, you can enhance soil quality, promote better nutrient uptake, and create the ideal growing environment for a lush, healthy lawn. For a wide selection of lawn care products for your lawn, check out myhomeTURF’s online store.