With fertiliser supply in Bangladesh in turmoil — road blockades in some districts and looting at dealers' godowns in others — agricultural scientists are pointing to nano fertiliser as a way out. Their argument is that if the technology is used effectively, the country could cut its fertiliser imports by up to 30 percent by 2030.

Feeding roughly 180 million people means fertiliser use on Bangladeshi fields rises every year. Scientists say the use of conventional chemical fertilisers such as urea, TSP and MoP has multiplied over the past two decades, forcing the country to import at rising cost while excessive application damages the soil. Waste, production cost and environmental pollution have all climbed with it.

Nano fertiliser means nitrogen, phosphorus and potassium, along with micronutrients such as zinc, iron and boron, manufactured at nano scale — between 1 and 100 nanometres. Ordinary fertiliser granules are visible to the naked eye; nano fertiliser particles are so small that up to 500 million of them can be mixed into a single litre of water.

Scientists describe three properties that set it apart. The small particle size gives far more contact area with a crop's leaves or roots. The particles are coated with polymer or clay, so the fertiliser feeds the plant slowly over 40 to 50 days and a single spray is enough. Sprayed on leaves it enters the plant directly through the stomata, and applied to soil it is drawn up easily by the roots.

The two most discussed products are nano urea and nano DAP, usually sold as a liquid in bottles. Many agricultural scientists reckon that 500 millilitres of nano urea can supply as much nitrogen as one 45-kilogram sack of urea. India, China and other countries have already begun using nano fertiliser in crop production.

Bangladesh's work on the technology began after the country's first international seminar on nanotechnology in 2012. That was reflected in the National Agriculture Policy framed in 2018, which included the use and spread of nano fertiliser, nano pesticide and nano sensors. But despite its place in national policy, the technology has barely reached the field, according to Professor Dr Md Tofazzal Islam of the agricultural university at Gazipur.

For a grower the calculation is simple: when the fertiliser supply is uncertain, the aman or rabi harvest is what is at risk. Since the start of the Iran-United States conflict, many farming economies have been hit on fertiliser as well as on energy, and they are now trying to build domestic production capacity. In that race, Bangladesh is still behind.

Source: BBC Bangla