Benefits of Using FGD Gypsum in Agriculture
Quantitatively, the use of FGD gypsum in agriculture is third only to wallboard production and as a raw feed for cement clinker.
There are a number of potential benefits of applying FGD gypsum to agricultural soils. These can be either chemical or physical.
Chemical benefits result from supplying essential plant nutrients calcium (Ca) and sulfur (S) for crop production or by modifying the subsoil to create a more favorable medium for plant root development (e.g., decreasing aluminum (Al) toxicity, promoting clay flocculation, enhancing root penetration, increasing water extraction from subsoil layers, etc.).
The physical benefits include the promotion of clay flocculation and aggregation of the soil, reduction of surface crusting which leads to increased water infilitration. These changes result in reduced runoff and erosion. For example, application of FGD material improves soil chemistry and increases water availability and crop yield as a result of reduction of subsoil chemical restrictions on rooting depth, while at the same time increasing water infiltration into the surface soil. A number of soil physical and related properties have been positively affected by the use of FGD gypsum such as reduced strength of suboil hardpan layers. Improved soil aggregation leads to improved soil aeration and reduced bulk density.
Of course, the use of FGD gypsum as a beneficial agricultural amendment must involve a well characterized study of the soil before application.