How to Use Gypsum on Lawns | Hunker
Determine how much gypsum you need for your lawn. A soil test can help determine the amount of clay in your lawn. Higher amounts of compacted clay in your soil will require a greater level of gypsum to produce the desired results. For heavily compacted soil, use 40 pounds of gypsum to cover 200 square feet, according to The Family Handyman website.