A natural claybreaker. An annual application will improve texture and add valuable calcium and sulphur. Use 125g per sq.m. heavy soils 500g per sq.m. Gypsum is chemically calcium sulphate or sulphate of lime, this is a little confusing, as its action is neutral. It is a natural rock, which is quarried, crushed and bagged. Another source of gypsum is as a bi-product of superphosphate which is approximately 50% each calcium phosphate and gypsum. Gypsum is an excellent soil conditioner and is the active ingredient in the commercial clay treatment products. It causes the fine particles in soil, and particular in clay soils, to stick together to improve drainage. Several applications each of 500gms. per sq. m. plus applications or organic matter and sand, will greatly improve soil texture and productivity. Gypsum is an excellent way of adding calcium to soil, which is an essential plant food, without radically altering the pH of the soil.
(Sulphate of Lime)