The production cut, due to maintenance at its German plants, amounts to 200,000 tonnes and follows one announced in September of 300,000 tonnes due to weak demand for potash, which is used to fertilise crops.
The world's largest producer of salt for food and de-icing said it now expected 2019 earnings before interest, tax, depreciation and amortisation (EBITDA) of 650 million euros (£560 million).
The two production cuts together resulted in a total cut in its full-year EBITDA guidance of 130 million euros from a previous estimate of 730-830 million euros.
Third-quarter EBITDA rose to 81 million euros, above a consensus forecast provided by the company of 78.4 million.
"Higher prices and increased sales volumes in the agriculture customer segment were decisive for the positive development" said the company in a statement.
K+S, which owns the Morton Salt brand, said revenue rose 8% to 905 million euros, beating a consensus forecast of 866.7 million.
It confirmed its free cash flow would turn positive this year for the first time since 2013 after posting a positive adjusted free cash flow of 204 million euros at the end of September.
That beat a consensus forecast of a negative adjusted free cash flow of 79.2 million euros.
(Reporting by Silvia Recchimuzzi in Gdansk; editing by Mark Potter and Jason Neely)