Shares in German fertilizer company K+S plummeted nearly 10%, as it painted a gloomy picture of potash demand in 2016.
"A downturn in the potash market, which first became apparent in the second half of 2015, may continue this year," K+S said.
"Along with intense competition, an ongoing difficult economic situation in the emerging market countries is expected, continued low agricultural prices, and less availability of credit for farmers, particularly in Latin America."
Global potash demand is expected to remain at its low 2015 level of 64m tonnes, as "purchasing restraint" remains in place.
K+S expected "intense competition" in the fertilizer market.
"Consequently, we are expecting a significant drop in the average selling price for the year as a whole," K+S said, pinning average 2016 prices at E307 a tonne.
Canadian broker Raymond James this week saw potash prices in the US Midwest at $270 a tonne, or around E242 a tonne.
Specialist fertilizer products could be negatively affected by high stocks, and the economic slowdown, K+S said, although prices was expected to be stable in Europe.
And K+S will also see lower sales volumes, due to restrictions in production at its Hattorf site due to a restricted licence to direct saline outflow into the Werra River.
"In view of this, temporary production restrictions at the Werra plant in the coming months cannot be ruled out until we receive the final decision regarding the longer-term licence which is expected in the summer of this year," K+S said.
German prosecutors are pressing charges against K+S employees, included its chief executive, over alleged illegal waste water disposal.
Courts have yet to decide if the case will proceed.
K+S forecast earnings to be "significantly" lower in 2016, with revenues down as well.
K+S reported sales of E4.18bn in the year to December 31 2015.
This is up 9% year-on-year, but came in short of analyst expectations of 4.26bn.
Profits were up 22%, to E782.0m, at the lower end of its forecast range, and shy of analyst expectations of E796.1m
K+S lifted its dividend for 2015 to E1.15, compared to E0.90 the previous year.
The dividend was raised to €1.15 per share, compared to €0.90 in 2014.
On Thursday K+S chief executive Norbert Steiner announced that he plans to stand down in May 2017, when his contract expires.
"I assume that I will move into retirement," Mr Steiner told a press conference, when asked about his plans.
K+S last year rejected a E41-a-share takeover offer from its Canadian rival PotashCorp.
"Storms may be coming your way," warned PotashCorp boss Jochen Tilk, in a letter formally withdrawing the bid back in October.
K+S shares were down 9.9% at E19.88 in afternoon deals in Frankfurt.