Leaders of the country’s largest corn and soybean groups last week said farmers need a new farm bill to provide a financial safety net as they prepare for another year of planting with low crop prices and tight profit margins.

“The skies are cloudy financially. It’s getting harder for farmers regardless of age to secure funding for their operation,” Ron Moore, an Illinois farmer and chairman of the American Soybean Association, said last week at the Commodity Classic in Anaheim, California. “The rocky farm economy underscores the need for a strong safety net....