The company cut the top end of its 2020 adjusted earnings per share forecast to $1.90 from $2.10 earlier, while retaining the lower end at $1.50.
Even as industrial utilization picked up in Asia, weak demand in Western Hemisphere hurt ammonia prices, Nutrien said.
The company said demand for urea was strong in India and expects Chinese urea exports to pick up pace in the second half, though they are lower year-on-year.
Revenue of $8.18 billion for the second quarter missed analysts' estimate of $8.35 billion, according to Refinitiv IBES.
Potash sales volumes in North America rose from an increase in U.S. planted acreage and more normal weather this spring, but prices still suffered as the benchmark was dragged by weak demand abroad.
Net potash sales outside of North America declined about 40% due to lower Chinese import demand and some short-term cautious spot purchasing in certain international markets, the company said.
The Saskatoon, Saskatchewan-based company's net income fell to $765 million, or $1.34 per share, in the three months ended June 30, from $858 million, or $1.47 per share, a year earlier.
On an adjusted basis, it earned $1.45 per share, beating expectations of $1.33, helped by lower costs.
(Reporting by Arunima Kumar in Bengaluru; Editing by Devika Syamnath and Sriraj Kalluvila)