Potash has emerged as a saviour for crops that faced heat wave as its sprays have helped farmers minimise yield loss, according to a report by scientists of Indian Council of Agricultural Research (ICAR). However, retail prices of potash are the highest among the all fertilisers in the recent subsidy announced by the Centre for the kharif season).

In Uttar Pradesh, about a 5-degree rise from the normal temperature in March this year resulted in mango flowers dropping and issues of poor pollination. Similarly in the Vidarbha region, citrus orchards witnessed fruit drop in several areas due to high temperature. ICAR’s research institutes had issued advisories for orchard growers to be followed during the months of April-May.

Among the recommendations, scientists had suggested two foliar sprays of 1-1.5 per cent potassium nitrate at an interval of 15 days during April-May. Similarly, in a village in Bihar, spraying of potassium nitrate at 0.5 per cent at boot leaf and flowering stages has significantly minimised yield loss caused by terminal heat stress, an ICAR report said.

Retaining moisture

“Potash helps in osmo-revolution process in plants. Due to osmotic pressure, turgidity in plants is maintained and regulates the opening of stomato. And when evapotranspiration does not happen due to it, plants retain the moisture level. Potash also helps in translocation of nutrient from leaves to grains,” said Vinod Kumar Singh, Director of Central Research Institute for Dryland Agriculture, Hyderabad. As potash use got neglected for a long time, it also had impacted moisture level in plants, added Singh, one of the authors of the report on heat wave.

However, the Cabinet approval on nutrient-based subsidy announced in April for the kharif season had pegged the price for muriate of potash (MoP) at ₹1,700/per 50 kg bag, against ₹1,350 for DAP and ₹242 for 45-kg urea bag. In June last year, MoP was about the same level as DAP. The average maximum retail price of complex fertiliser (N, P and K combined) is about ₹1,400 per 50 kg bag.

Hike in subsidy

However, officials said the subsidy on potash has been increased by 150 per cent to ₹25.31/kg from ₹10.11/kg as against a 60.5 per cent increase in DAP to ₹72.74/kg from ₹5.32/kg. In the case of urea, the subsidy has gone up five-fold to ₹91.96/kg from ₹18.78/kg.

In 2021-22, import of DAP increased by almost 12 per cent to 54.62 lakh tonnes (lt) whereas urea import declined 7 per cent to 91.36 lt, MOP (for agricultural use) dropped by 45 per cent to 17.68 lt and that of complex fertiliser fell by 16 per cent to 11.70 lt, data show.