Efficiently use low quality irrigation water: Use of reclaimed municipal wastewater is important for conservation of natural resources. Reclaimed water can be satisfactorily used if amended with gypsum and water-soluble polymers.
Improves fruit quality and prevents some plant diseases: The quality of fruit depends on the amount of calcium. Calcium is nearly always only marginally sufficient and often deficient in developing fruits. Calcium moves very slowly, if at all, from one plant part to another and fruits at the end of the transport system get too little. Calcium must be constantly available to the roots. In very high pH soils, calcium is not available enough; therefore, gypsum helps. Gypsum is used for peanuts, which develop below ground, to keep them disease free. Gypsum helps prevent blossom-end rot of watermelon and tomatoes and bitter pit in apples. Gypsum is preferred over lime for potatoes grown in acid soils so that scab may be controlled.
Decreases loss of fertilizer nitrogen to the air: Calcium from gypsum can help decrease volatilization loss of ammonium nitrogen from applications of ammonia, ammonium nitrate, urea, ammonium sulfate, or any of the ammonium phosphates.
Keeps clay off tuber and root crops: Gypsum can help keep clay particles from adhering to roots, bulbs and tubers of crops like potato, carrots, garlic and beets.
Helps Earthworms to Flourish: A continuous supply of calcium with organics is necessary for the habitat of earthworms that improve soil aeration, improve soil aggregation and churn the organic matter with inorganic fraction of soil.
Dr Sarvesh Kumar Shah
Department of Agricultural Sciences,
The Fertiliser Association of India, New Delhi