69. Consider the following statements about Gypsum
1. It is a naturally-occurring substance
2. It is used as a soil amendment for agricultural purposes
3. Plaster of Paris is made by heating it to high temperatures
Which of the above statement(s) is/are correct?
Gypsum is used as a fertiliser; it is a moderately soluble source of the essential plant nutrients, calcium and sulphur, and can improve overall plant growth. Gypsum amendments can also improve the physical and chemical properties of soils, thus reducing erosion losses of soils and nutrient concentrations (especially phosphorus) in surface water runoffs . Gypsum is the most commonly used amendment for sodic soil reclamation and can be included as a component in synthetic soils used in nursery, greenhouse, and landscape applications. These multiple uses of gypsum represent potential benefits to agricultural and horticultural users.
PoP is made by heating gypsum at temperatures in the range of 300°F. When it comes in contact with water, the material regains the form of gypsum. Since gypsum is a naturally occurring substance, and is used as a soil-conditioner to reclaim saline-sodic soils, it has been argued by idol-makers’ associations that it is harmless to the environment. This argument, however, is trashed by activists who argue that PoP idols are non-biodegradable. A test carried out at the Centre for Environmental Science and Engineering at IIT-Mumbai, showed that these idols remain intact for several months in still water, as compared to clay idols which dissolve within 45 minutes.