CHICAGO, March 31 (Reuters) - U.S. farmers plan to plant less corn and more soybeans this year compared to last year, the Agriculture Department said, as fertilizer and fuel prices rise due to the war with Iran, in the latest blow to an already struggling agricultural sector.

The ministry on Tuesday released its first estimate of crop area for this year based on a survey, along with quarterly data on U.S. grain stocks.

Analysts cautioned that the planted area estimates, based on surveys conducted with farmers in the first half of March, could not fully account for the disruptions and price effects of the war. They said the ministry might further reduce its estimates for maize planting.

Jake Hanley, managing director and senior portfolio specialist at Tuocrium Trading, said, "Due to what's happening in the fertilizer market, and the timing of the survey, this is likely to be the highest number of maize acreage we'll see this year."

Growing corn and wheat requires more expensive fertilizers, making them less attractive to farmers compared to growing soybeans, especially with the US-Israeli war on Iran cutting off vital nitrogen supplies from the Gulf to farmers worldwide.

Rising fertilizer costs represent the latest obstacle for farmers struggling with weak grain prices, high costs for other inputs, and uncertainty about Chinese demand for U.S. crops.

The trade war launched by the Trump administration last year has significantly disrupted U.S. soybean export sales to China, the world's largest importer.

Farmers plan to plant 95.338 million acres of corn this year, down from 98.788 million acres in 2025, and 84.7 million acres of soybeans, up from 81.215 million acres last year, according to data from the U.S. Department of Agriculture.