Aug 5 (Reuters) - Fertilizer producer Mosaic MOS.N reported second-quarter adjusted earnings below Wall Street estimates on Tuesday, as higher costs weighed against gains from stronger potash prices and robust sales in Brazil.

Shares of the company fell about 7% in after-hours trading.

Prices for key nutrients such as potash and phosphate have started to stabilize after earlier volatility driven by geopolitical disruptions.

However, broader headwinds in the agricultural chemicals sector, which continues to be affected by U.S. tariffs and crop price volatility, impacted Mosaic's quarterly performance.

The company reported that total operating expenses rose to $107 million in the second quarter, up from $32.3 million a year earlier.

Additionally, it faced an increase of $66 million in idle and turnaround expenses, reflecting higher maintenance and downtime costs.

Net sales in the potash segment rose by 7.2% to $711 million, compared to $663 million in the prior year's quarter, while phosphate segment sales held steady at $1.2 billion.

Betting on strong demand in Brazil and Asia, Mosaic raised its full-year potash production forecast to between 9.3 million and 9.5 million tonnes, up from the previous forecast of 8.7 million to 9.1 million tonnes.

The Tampa-based company reported an adjusted profit of 51 cents per share, missing analysts' average estimate of 73 cents per share, according to data compiled by LSEG.

(Reporting by Khusbu Jena; Editing by Mohammed Safi Shamsi)

((Khusbu.Jena@thomsonreuters.com;))