The complex will have capacity of nearly 3 million tons a year, including 2.4 million tons of phosphate fertilizers and 570,000 tons of nitrogen fertilizers.
The Department of Agriculture warned that a strong El Niño could cut rice production by up to 700,000 tonnes, or 3.5% of the annual target.
Corn, wheat and rice imports are expected to rise to make up the difference as the United States continues to be the main supplier for grain and feed.
This growth pushes year-end projections toward the 400,000-ton mark, according to ITALMOPA, the Italian Association of Industrial Millers.
The market expansion comes amid ongoing concerns about global food security.