This includes 700,000 tonnes of Sulphate Amonium (SA) and 900,000 tonnes of potassium. Potassium and SA are not made in Viet Nam and have to be imported.

The total demand this year is expected to be around 9.6 million tonnes while domestic producers can only supply 7.26 million tonnes.

To ensure adequate supply, especially of important fertilisers such as urea, manufacturing plants should operate at full capacity, the ministry said.

They have to step up inspection of urea quality and prices in the market, especially during the peak demand period when the winter-spring rice crop is grown, it said.

The fertiliser industry needs to soon adopt advanced technologies and large-scale production, and set up an efficient distribution network to ensure adequate supply of quality and reasonably priced fertilisers, it added.

The demand for urea in the first quarter is around 570,000 tonnes, the PetroVietnam Fertiliser and Chemicals Corporation (PVFCCo), the country's largest producer, said.

PVFCCo will produce around 300,000 tonnes of urea in the period and has stocks of 250,000 tonnes.

The Viet Nam Fertiliser Association said earlier this month domestic urea supply would stabilise when some large plants start operating regularly in the last quarter.

When the Ca Mau and Ninh Binh fertiliser plants, with an annual capacity of 800,000 tonnes and 560,000 tonnes respectively, begin operation, the annual national output will top 2.36 million tonnes.

With the full-year demand at around 1.8 million tonnes, the country does not have to depend on imports, the association said.

At the end of this year, the country can even become an exporter, it added.