With some of the best soil for agriculture in the world, Illinois has been looking to add a third crop to its traditional corn and soybean rotation. Cannabis, it turns out, could be a strong contender.
However, it’s currently illegal to grow cannabis outdoors commercially, even in states where it’s recreationally legal, according to state laws.
Cannabis, like corn and soybeans, is an annual plant, meaning the seed a farmer sows one year won’t spring up the following season, according to Purdue University’s Center for New Crops and Plants Products. This means cannabis could fit into a crop rotation without farmers having to get extra machinery to remove roots or left over plant.
Theresa Johnston, a lecturer in the Institute of Environmental Sustainability (IES) at Loyola, said Illinois’ amazing soil has attracted a variety of soil organisms.
“The more variety of plants you have the more variety of soil organisms you’ll have,” Johnston said. “Organisms help maintain a healthy ecosystem which helps plants thrive, so in a natural ecosystem, you don’t have to fertilize or anything like that. In a crop system, you’ll often see a lot of those nutrient inputs because [farmers] will lose that soil ecosystem.”
Olivia Niosi, a senior environmental science major who studies how different nutrients limit plant growth within a lab in the IES, said although Illinois has historically excellent soil, the land has been used for farming for so long the nutrients that used to be in the soil have diminished and farmers now rely more on fertilizers.
“Like soybeans and corn, cannabis is also sensitive to growing in low nutrient conditions, so if it were to be planted outside in the same field as the corn and soybean fields it would likely also need heavy fertilization,” Niosi said.
Cannabis is often grown indoors partly because the variables for growing it, such as temperature, acidity and nitrogen and phosphorus can be controlled. It’s also grown indoors because it isn’t federally legal yet, according to Johnston.
While growing indoors can ensure the crop is in ideal conditions, space is often limited in greenhouse growing environments, according to Johnston. Revolution Enterprises, based in Chicago, has had success growing cannabis indoors. However, Kevin Pilarski, Revolution Enterprises’ chief commercial officer, said it would be unlikely for the company to grow cannabis outdoors in Illinois in the near future.
“The current bill as it stands doesn’t allow for any outdoor growing,” Pilarski said. “The theory is that would create a nuisance, people might try to steal it or the smell might be too strong, especially around schools.”
Although medical and recreational cannabis can’t be grown outside, Congress recently passed a bill called the 2018 Farm Act which allows hemp to be grown outdoors. Hemp is cannabis with less than 0.3 percent THC — the chemical which induces the feelings associated with being high.
Niosi said as plants grow, the soil adjusts to contain more of the nutrients the specific plant needs.
“If we were to plant cannabis, the soil would likely change in a way so that it’s more reflective of what soil cannabis would want and what nutrients it’s uptaking more than other plants that are around it,” Niosi, 22, said.
Much of Illinois’ soil developed under prairies and grasslands; the plants in these areas have deep roots that survive through winters. These conditions give the soil a deep topsoil layer, which is where most of the nutrients for plant growth is stored.
The state soil is known as drummer. This nutrient-rich soil, with 40 to 60 inches of silty topsoil, covers over 1.5 million acres of Illinois, according to the Natural Resources Conservation Service (NRCS). This is the most productive soil and most abundant in Illinois, which is why the state is so agriculturally productive, according to the NRCS.
Some areas of Illinois, including the Southern regions and areas of intensive farming, have clay-heavy soils. This means the soil is more compact and therefore makes it more difficult to absorb water. Soils that can’t remove water are more saturated; this is not preferred by cannabis crops and often results in crop loss.
However, up to 85 percent of Illinois farmland has tile drains installed to move excess water off the fields, according to a 2017 report by the American Society of Landscape Architects. Tile drains are clay, plastic or metal piping that sits below the soil surface and deposits water into nearby drainage ditches or water sources.
Cannabis, unlike corn and soybeans, must be grown without most pesticide applications since it can’t be washed the same way as the other crops. However, all plants have natural repellants of pests, and cannabis likely has these deterrent qualities as well, according to Johnston.
“If [the farmer] is maintaining good soil health, it shouldn’t be a problem,” Johnston said. “A lot of times the chemical we’re seeking in the plant is there to defend the plant against pests.”
Niosi said despite the potential benefits, Illinois farmers might face challenges with Illinois’ climate. She said cannabis can be sensitive to mold, acidity and cold temperatures which are almost impossible to regulate outdoors in Illinois.
Specifically, the cold temperatures and early winter could cut the cannabis growing season short which would mean farmers wouldn’t be able to harvest as much product, according to Niosi.
“It would be hard to [grow cannabis] organically outside in Illinois,” Niosi said. “I think that it would have to be in an indoor greenhouse operation in order to grow enough for the demand of Chicago and other large cities.”
Johnston said while temperature can limit or hurt growth, cannabis, like tomato plants, could use shades to cover from extreme temperatures and high sun exposure to avoid injury to the plant.