Obtain a soil test kit from your county extension office and send in the soil samples for a full nutrient analysis. If the results state that your soil is deficient in iron, magnesium or manganese, do not use gypsum, as it will further leach the soil of these nutrients. If the soil has a high soil salt concentration, gypsum will benefit the soil.
Purchase granular grade gypsum for your soil at a rate of 40 lbs. per 1,000 square feet.
Place the gypsum into a seed disperser and disperse it throughout the yard.
Work the gypsum into the soil to a depth of 1 foot using a trowel. While the gypsum can be simply applied to the surface, it will incorporate at a faster rate when properly added into the soil.
Water the soil immediately after working in the gypsum. Irrigate the entire area with at least 2 inches of water for optimal absorption.