A bipartisan group of lawmakers introduced legislation in the U.S. House and Senate last week to restrict eligibility for the 45Z tax credit to renewable fuels derived from domestically sourced feedstock. The proposed legislation would also extend the credit for seven additional years.

The Farmer First Fuel In­centives Act is co-led in the Senate by U.S. Sens. Roger Marshall (R-Kan.) and Sherrod Brown (D-Ohio). Companion legislation was introduced in the House by U.S. Reps. Tracey...