Credit Suisse forecast potash prices to fall until at least 2018, as it warns on "false hope" in the agricultural sector.
"It remains too early to call the cycle bottom and we remain cautious on the sector," Credit Suisse said.
"In our view, potash markets are the most at risk," the bank warned.
Credit Suisse warned of "false hope for an ag cycle rebound".
And even in crop prices do rise, the bank remains bearish on crop nutrient prices, due to long term oversupply of the market, and heavy inventories.
Although fertilizer inventories have been shrinking, Credit Suisse argues that this was "more of a structural shift in purchaser behaviour".
Credit Suisse said lingering volatility in emerging market was impeding growing, with headwinds to demand likely to continue.
"Despite the Brazilian real and other currencies stabilizing, we note that credit and end market demand for fertilizers remain an issue," said the bank.
The bank was most bearish on prospects for potash prices, suggesting that a price recovery "will elude us for years, not quarters".
"We maintain our view that persistent market oversupply is the primary culprit for weaker prices."
The bank forecast falling prices across all major potash markets over the next two years.
Credit Suisse sees potash prices in China falling to $263 a tonne in 2016, from $313 a tonne in 2015.
And prices are seen falling further, to $200 a tonne in 2017 and $190 in 2018.
Last month the Belarusian miner Belaruskali signed a potash supply deal with Indian buyers at $227 a tonne.
But no deal has so far been struck between the major potash suppliers, Belaruskali, Uralkali, and Canpotex, and China.
These Chinese contracts, which usually set the floor for world potash prices, are more normally signed at the start of every year, but have been delayed in 2016 due to hard Chinese bargaining.
"We now see any 2016 contract being signed no higher than $210 a tonne, given global price pressures, "Credit Suisse said.
"The longer producers wait to sign a contract, the more pricing pressure evolves in key regional markets, which in turn gives the Chinese more bargaining power," Credit Suisse said.
Thanks to heavy Chinese port inventories, domestic producers are "under little pressure to secure product as the spring application window has now diminished".
The potash price outlook remains bearish in the US as well.
"We continue to believe US prices will remain at lower levels, particularly as "La Nina" euphoria continues to wane in the form of corn and soy price declines," the bank said.
Prices were forecast to fall $46, to $250 a tonne in 2016, down to $225 in 2017, and $220 in 2018.
Credit Suisse was more upbeat on prospects for nitrogen nutrients, such as ammonia and urea.
"As expectations remain the lowest for nitrogen, we still believe it is the best house in a horrible neighbourhood, but stress the entire sector will likely remain volatile for the balance of 2016 and into 2017" Credit Suisse said.
US ammonia prices were seen falling $150 a tonne, to $304 a tonne in 2016, before recovering to $325 a tonne in 2017, and $340 a tonne in 2018.
"Despite some investor optimism, we remain cautious on phosphates," Credit Suisse said.
Phosphate prices in the US were forecast to fall to $344 a tonne in 2016, down $115 a tonne from 2015 prices. Prices were seen falling to $340 a tonne in 2017, before recovering a little to $350 in 2018.