DAP ‘shortage’

DAP ‘shortage’

Subject – Agriculture

Context – An acute shortage of di-ammonium phosphate (DAP) in Haryana has seen desperate farmers pelting stones at the police, blocking roads in protest, and even resorting to “loot” the fertilizer from a private dealer’s outlet in Mahendragarh district of south Haryana.

Concept –

Why is DAP so important for farmers?

• Being a basic nutrient for Rabi crops, the DAP fertiliser has to be sprinkled at the time of sowing crops like mustard and wheat.
• The farmers say they need a bag of at least 45 kilos for sowing an acre of land. Any delay in its supply could adversely impact the sowing of crops.

What is DAP?

• Diammonium phosphate is one of a series of water-soluble ammonium phosphate salts that can be produced when ammonia reacts with phosphoric acid.
• When applied as plant food, it temporarily increases the soil pH, but over a long term the treated ground becomes more acidic than before upon nitrification of the ammonium.
• It is incompatible with alkaline chemicals because its ammonium ion is more likely to convert to ammonia in a high-pH environment.
• The average pH in solution is 7.5–8.
• DAP can be used as a fire retardant. These are important effects in fighting wildfires as lowering the pyrolysis temperature and increasing the amount of char formed reduces that amount of available fuel and can lead to the formation of a firebreak.
• DAP is also used as a yeast nutrient in winemaking and mead-making; as an additive in some brands of cigarettes purportedly as a nicotine enhancer; to prevent afterglow in matches, in purifying sugar; as a flux for soldering tin, copper, zinc and brass; and to control precipitation of alkali-soluble and acid-insoluble colloidal dyes on wool.

Natural occurrence

• The compound occurs in the nature as the exceedingly rare mineral phosphammite. The related dihydrogen compound occurs as the mineral biphosphammite. Both are related to guano deposits.