Hemp was an important industrial crop in the US until the 1938 Marijuana Tax Act deemed it an illegal crop. Recent regulations have now authorized hemp production on a restricted basis and many are interested in its use as a forage crop. First, Hemp is not marijuana. Hemp must have <0.3% THC, the main psychoactive compound in marijuana (average street marijuana will have around 10% THC). Hemp is also similar to kenaf, a crop that has been used as a forage crop in the past.
Dr. Ben Goff, UK forage agronomist, recently presented the results of a study evaluating hemp and kenaf as forage crops at the AFGC annual meeting in Roanoke, VA. Grain, fiber and dual-purpose varieties of hemp and one variety of Kenaf were planted at two planting dates (late May and late June) and evaluated for forage quality and yield. Both planting dates resulted in crude protein values greater than 12% DM for the first 90 days after planting suggesting that both hemp and kenaf could be viable forage crops.
Although it will never become a major forage crop, hemp may be able fill a niche role as a warm season annual forage. Additional research is needed to determine the best agronomic practices and feeding trials are needed to evaluate animal performance. Seed availability and costs, heavy regulations and public perception will likely hinder wide-spread use of this crop in the near future. ~Ben Goff and Krista Lea