Q: I’ve heard that applying gypsum to my turf will help reduce salts in the soil. Is that true?

A: That is partially true. Many would be surprised to know that gypsum (calcium sulfate) is actually a salt. It’s a “good salt” that contains calcium to support turf growth.

Surface-applied gypsum or gypsum added to the irrigation water increases salinity and aids in water penetration. When combined with a deep watering cycle (leaching), the gypsum helps to flush excessive salts from the soil and also helps to counteract the negative effects of excess sodium (which is a completely different animal that negatively impacts soil structure).

So gypsum alone will not reduce the level of soluble salts in the soil. It has to be combined with deep watering to be effective. If sodium levels are not a concern, wetting agents in combination with deep watering does an effective job of reducing soil salinity.