Growing industrial hemp may seem like a novel practice in agriculture but Missouri actually has a history as a leader in hemp production. That history, however, doesn’t mean there isn’t much to learn about the crop with its resurgence in the state.
At the Barton County Soils and Crops Conference held last week in Lamar, Missouri, the history and agronomics of hemp production were discussed by Greg Luce, University of Missouri small grains specialist.
“The First Battle of Lexington is often called ‘The Battle of Hemp Bales,’” Luce said. “There was a lot of hemp grown in Missouri in the 1800s, starting from about the 1830s until about the 1880s. Missouri and Kentucky were the two leading states in hemp production, and at that Civil War battle, the Confederates fought behind baled hemp.”
Today, hemp may be found where it was grown in the 1800s as a crop, Luce said, explaining Missouri phased out of hemp production as cotton grew in popularity for textiles. Despite the U.S. Department of Agriculture’s prediction in 1916 that hemp would become a major source of wood pulp for paper, the 1930s saw a marijuana act that outlawed the crop.
“During World War II, there was somewhat of a resurgence of growing hemp for fiber for the war effort,” Luce said. “We couldn’t get hemp rope from other parts of the world during the war so they started growing it again. Missouri did grow some hemp back in the 1940s but then that was just a little blip in terms of production.”
The Controlled Substance Act of 1970 then made it completely illegal, he added. However, when the lieutenant governor signed an act to allow research to be done on industrial hemp last June, it opened a new door.
“All of the hemp that’s a true cannabis hemp is Cannabis sativa,” Luce said, “and that would include marijuana.”
The differentiator between marijuana and the legal hemp, he explained, is the THC level. “[Industrial hemp] needs to be below 0.3 percent THC content, which is a very low percent,” Luce said. “It’s safe and would have no effects in terms of any drug effect.”
Industrial hemp can be used for grain, processed for oil, used for fiber and many other purposes, Luce said.
“The issue as far as where we’re at is that although it’s kind of a ‘new-old crop’ — it used to be grown in Missouri but we haven’t done it in a long, long time — we haven’t got experience with growing industrial hemp in Missouri and what kind of agronomic practices would be best.”
An example is the lack of chemicals available for use in the crop.
“Weed control will be a consideration,” he warned producers interested in potentially growing the crop.
“There’s no pesticides labeled for it right now so we’re working around trying to control weeds and other pests without pesticides and that’s a challenge, especially for weed control,” the specialist said. However, he did state that should change as weed scientists know some pesticides that will work in the crop but they are not yet currently labeled for it.
Luce also explained hemp has sensitivity to some soybean herbicides and the residual carryover can really impact the crop.
Another consideration is the Missouri Department of Agriculture is working on standards for the crop and is currently accepting applications from producers interested in growing the crop.
“They’re going to have in place very soon a procedure for sampling and they’re going to require certified sampling be done,” he said, “so there would be an opportunity for folks in the ag industry who want to become a certified sampler to do that.
“They’ve already had a number of people apply to be growers for this coming year,” he added.
Agronomically, Luce compared industrial hemp to other crops.
“It’s a summer annual so it’s like a soybean,” he explained.
“It’s very photoperiod sensitive like soybeans. It’s day-length sensitive but even more so than soybeans,” he continued, so a late planting will have an effect on the plant when compared to planting at the ideal time. He also said hemp is mostly dioecious, or it has male and female plants.
Though many people are interested in growing industrial hemp for cannabidiol, or CBD, Luce said growing industrial hemp for grain, fiber or both grain and fiber is probably a better fit when considering how agricultural producers currently operate.
“Growing hemp for fiber is more like a hay production system,” he explained, adding he expects 6 to 8 ton yields with possible yields of up to 10 tons. CBD-type production requires much more labor, care and investment than grain and fiber crops.
“Even in the species, there’s a lot of variation in the growth habits,” he said. Different types of plants will be suited for different types of production.
Fertility requirements, he said, will be similar to wheat or corn with a desired pH in the mid-sixes. Nitrogen requirements will vary depending on what type of industrial hemp is being grown.
“If we’re raising it for grain, we want a higher nitrogen level,” he said. “Just to raise it for the fiber, 50 to 60 pounds of nitrogen is probably going to be sufficient.”
Potassium and phosphorus will need to be applied according to soil test results. “If we’re taking that forage off of the field, one nutrient we’re going to take a lot out of is potash, so that’s something we’ll have to watch.
“I’ve heard it said that hemp will grow anywhere,” Luce said. “Well, that doesn’t seem to be the case.
“It doesn’t like poorly drained fields. It doesn’t like wet feet — it doesn’t do well in those situations at all.”
Additionally, producers will need to sow hemp into a clean seedbed, making no-till production difficult.
Hemp seed is small and fairly hard, and Luce recommended seed germination testing.
“The seed depth is really critical,” he said. “If you’re planting seed for grain or fiber, you don’t want it very deep. You want it really shallow — a quarter to half-inch deep is about all you want — and a good, firm seedbed.”
Seed-to-soil contact is essential so Luce said rolling the seedbed might be a recommended. He also said he saw better emergence with a planter than a drill because of better seed-to-soil contact.
A high seeding rate, about 50 pounds to the acre for a fiber-type crop, is also essential to get a good canopy to help with weed control, Luce explained. For grain, he said 15-inch rows might be an option.
Overall, Luce stated he sees potential in industrial hemp for Missouri.
“I think it’s got a place,” he said. “I think there’s a lot of opportunities.”