Gypsum how does it work

Gypsum should also not be used in soils with low sodium levels as the mineral may deprive the soil of the existing saline content. If you want to plant some veggies or flowers, then for every square foot, 20 to 30 pounds of gypsum is sufficient. For existing plants, 40 pounds per one thousand square feet is adequate. Liquid gypsum is a form of fast-acting gypsum or rapid gypsum that helps prevent waterlogging, loosens clay, improves soil drainage, and removes excess saline content from the soil.

Powdered gypsum is in the form of a fine powder and is more beneficial for new garden beds. If you have a lawn that has already been set up, then you should apply gypsum after lawn aeration. Hopefully, you now have adequate information about what gypsum is, its uses, advantages, and how to use it. With this knowledge of how, when, and how often to apply gypsum to your garden, you can go ahead and reap the benefits of gypsum for all your gardening needs.

Author: Matt Hagens. I love to be outside working on my lawn, planning my next project. I created this website to help people like you find the best products for yard care and great advice. Learn more about me and find me on Facebook. It contains calcium ions and sulfate ions, both of which are plant nutrients.

Gypsum is a favorite amendment for soil, especially clay soil where it is claimed to do all kinds of wonderful things.

From my book, Soil Science for Gardeners :. These soils become difficult to till, have poor seed germination and make it difficult for plants to grow. Soil in costal regions can be sodic, as can agricultural land that has been watered with sea water.

Arid regions with very low rain fall can also be sodic because the salt migrates from lower levels to the surface where evaporating water leaves the salt sodium behind. A SAR lab test determines if soil is sodic.

In sodic soil, the sodium ions disrupt the clay structure. The soil drains poorly, is sticky when wet, hard when dry, and contains very little air for plant roots. In such a situation, the calcium in gypsum knocks the sodium ions off the clay and replaces them with calcium ions. The sodium gets washed deeper into the soil profile by rain and irrigation. The result is soil with much better structure. But here is the problem.

Gypsum does NOT improve the structure of most clay soil, nor does it make it less sticky or improve root growth.

For the reason just discussed, gypsum will improve drainage on sodic soil, but it does nothing to help drainage on non-sodic soil. This is a very common myth that is simply not true. It probably stems from the use of lime to raise pH. Lime is calcium carbonate which sounds a lot like calcium sulfate gypsum , but they are very different.

The calcium in both of these does increase pH, but the sulfate in gypsum reduces pH. The net effect is that gypsum does not change pH. Many garden soils are not deficient of calcium, in which case adding any form of calcium is a waste. How do you know your calcium level? G et a soil test done. Gypsum has three typical uses in the home lawn or garden.

It can help reclaim sodic soils, it may enhance soil structure especially in sodic soils , and it may also be used as a calcium and sulfur fertilizer. Sodic soils are soils which are very high in sodium, to the point that it effects plant growth and development as well as the physical condition of the soil. On a soil test, a sodic soil would be classified as having an electrical conductivity value below 4, a sodium absorption ratio above 13, and an exchangeable sodium percentage above 15 along with a dispersed lacking significant soil structure or aggregates physical condition.

There is a Pacific Northwest Extension publication, which is a collaborative effort between Oregon State University, University of Idaho, and Washington State University, available that well outlines reclamation steps in salt effected soils. How does it work or help reclaim sodic soils?

The sodium also often pulls on the water more strongly the plants can, causing them to wilt. Ultimately, we need to get the sodium out of the root zone of our lawn or garden. When we apply gypsum, and water it in, the calcium and sulfur break apart chemically; then calcium replaces the sodium on the soil particles and actually pulls them together to function as larger particles that will then let more water move in and through the soil. In summary, gypsum is an excellent fertilizer source of Ca and S.

If application of these plant-essential nutrients is needed, then it works well. However, for Iowa soils both Ca or S are in good supply. Iowa soils inherently have a capacity for providing adequate levels of exchangeable Ca and S for crop production. Thus, more is not necessarily better.

Table 2. Corn and soybean yield response to gypsum and elemental S application, average across six sites in Iowa. You are here Home. Gypsum: an old product with a new use Encyclopedia Article. Gypsum as a fertilizer? Gypsum as a soil amendment Soil structure is impacted by exchangeable cations positively charged ions.