Loosen Clay Soils

• The main benefit of gypsum is that it helps to loosen heavy clay soils. This provides more pockets for the air and water to travel to the plant roots. Yearly application of gypsum to a clay soil can increase water flow 100 percent.
  
  

Nutrient Source

• Gypsum is an ample source of calcium and sulfur. Gypsum is sought after because it is highly soluble, and readily releases calcium and sulfur into the soil. Acid soils are usually deficient in calcium, which makes gypsum excellent for acid-loving crops.
  
  

Detoxification

• Gypsum can be used to balance and adjust the ill effects of a few toxic soil chemicals. Gypsum offsets the effects of a toxic amount of aluminum in soils with a low pH. Gypsum can also be used, according to soilsolutions.net, to help "curb phosphorus runoff from soils." Gypsum can also be used to decrease the ill effects of too much magnesium in soils.
  
  

Application Rate

• For established lawns, 40 to 50 lbs. of gypsum should be applied for every 1,000 square feet, twice a year. New lawns should have 100 to 200 lbs. for every 1,000 square feet. These quantities should be doubled for soils with extremely high clay content. Lawn should be watered after gypsum is spread.
  
  

Increase Nitrogen Efficiency

• According to research performed by Ohio State University, the presence of gypsum increases the efficiency of nitrogen. The study concluded that in a silt loam soil with a neutral pH, low-rate nitrogen mixed with gypsum had a significantly higher yield than a high-rate nitrogen by itself.