Mosaic will invest an additional $1.35 billion to further develop a large potash mine in Saskatchewan.

The Plymouth-based company said Monday it plans to accelerate the mine's production ramp-up, which will entail more investment over the next eight years.

Mosaic is one of the world's largest fertilizer companies, mining potash and phosphate and processing those minerals into crop nutrients. Mosaic's largest potash operations are in Saskatchewan; its biggest phosphate mines are in south central Florida.

The new $1.35 billion earmarked for the K3 project near the town of Esterhazy follows an earlier investment of $1.2 billion. The K3 mine is expected to begin producing potash ore in 2017.