
The once barren fields at the University of Mississippi are now bursting with research-grade cannabis. Scientists with the Marijuana Project have bred the plants to create different strains, each with varying levels of THC, the ingredient in marijuana that makes users high, and CBD, which has medicinal properties.

Today, with more studies anticipated, the farm has ramped up production and the marijuana plants are a towering 5 to 6 feet tall.

The University of Mississippi was selected in 1968 to exclusively provide the marijuana needed for government-approved studies. At first, it tested marijuana seized by the government. It wasn't until the 1970s that the farm started producing its own research-grade cannabis.

Before 2014, the last time marijuana was grown at the University of Mississippi was 2007.

The marijuana plants at Ole Miss start off in this extremely controlled and monitored grow room before they are planted in the fields outside. The plants require water, light and temperatures between 75 and 86 degrees Fahrenheit (24 and 30 degrees Celsius).

Over the past year, production at the farm has increased by 30 times, from 46 pounds (21 kilograms) of harvested marijuana to 1,400 pounds (635 kilograms).

After being harvested, the marijuana is placed on racks in a dark, climate-controlled vault to be dried.

The marijuana at the lab is dried on screens, which allows airflow from all directions.

After the plants have been thoroughly dried, they are processed to ensure that the marijuana is completely clean and devoid of seeds, stems, stalks and debris.

The final product is this processed marijuana, which accounts for 14% to 16% of the weight of the whole plant.

The marijuana produced at the University of Mississippi is then stored in a DEA-approved vault, ready to be used in federally approved studies.

Sanjay Gupta, CNN chief medical correspondent, and Dr. Mahmoud ElSohly, the director of the Marijuana Project, tour the marijuana fields at Ole Miss. ElSohly has been in charge since 1981.