WASHINGTON — The number of acres of hemp licensed in the United States reached 511,452 acres in 2019, up from 78,176 acres in 2018, according to the 2019 U.S. Hemp License Report from Vote Hemp, a Washington-based hemp advocacy organization. The increase came after the farm bill removed hemp from the Controlled Substances Act.

“We are seeing cultivation dramatically expand in the U.S. in 2019, with over quadruple the number of acres licensed in hemp compared to last year and the addition of 13 more states with hemp programs,” said Eric Steenstra, president of Vote Hemp. “Now that we have lifted federal prohibition on hemp farming, it’s time to build the infrastructure and expand hemp cultivation and the market for hemp products across the country so that all can reap the benefits of this versatile and sustainable crop.”

This year 16,877 state growers’ licenses were issued, which compared with 3,546 in 2018.

President Donald Trump signed the farm bill into law on Dec. 20, 2018. It defined hemp as cannabis that contains no more than 0.3% tetrahydrocannabinol (T.H.C.). If the plant has more than 0.3% T.H.C., it is classified as marijuana, which is a controlled substance.

The food industry is waiting to see how the Food and Drug Administration will regulate hemp. The F.D.A. has approved Epidiolex, which contains cannabidiol (C.B.D.) extracted from hemp, as a drug. The F.D.A. thus concluded dietary supplements and/or foods with C.B.D. cannot be sold because C.B.D. is an active ingredient in a drug product. The F.D.A. is exploring potential pathways that would allow dietary supplements and/or conventional foods containing C.B.D. to be marketed lawfully.

Hemp seed contains both omega-3 and omega-6 fatty acids along with protein, fiber, vitamins and minerals, according to Vote Hemp. Besides foods and beverages, hemp extracts may be used in batteries and packaging materials. “Hempcrete” may be used to build houses, according to Vote Hemp.