THE ENVIRONMENTAL PERSPECTIVE OF CANNABIS CULTIVATION
Author: Luke Khoury, Senior Scientist
As the California cannabis industry approaches the end of its’ second legal year, it becomes appropriate to examine the environmental impacts of this burgeoning industry. Beyond the industry’s economic developments are the numerous environmental effects caused by the rapid pace of agro-industrial progress. As production accelerates, so will the need to optimize processes that directly impact the environment. Factors such as resource usage and maintenance of environmental integrity must be addressed appropriately. Cultivation strategies encompass a wide range of approaches, including a variety of indoor and outdoor harvest cycles. However, due to prohibitive federal policies and the symptomatic, quasi-legal status of domestic cannabis production, it is difficult to ascertain a true understanding of impacts across all cultivational environments. A requisite for policy that lends support for environmental regulation is generally well accepted. By understanding practices involved in cannabis production across various environments, suitable directives can be implemented to enhance best practices for the cannabis industry.
A substantial portion of legal cannabis cultivation is conducted inside of tightly controlled grow facilities. Many inherent benefits may arise from this practice, including stringent quality control over maintaining optimal grow conditions for temperature, water, and nutrient application. The high degree of influence over these conditions does come at a price, generally in the form of resource use. For example, a 2017 study estimated that the power density of cannabis cultivation facilities is equal to that of data centers in the United States and accounts for approximately 1% of the national average energy use.1 Considering this metric was obtained for illicit national production and not specifically California’s legal market, there is incomplete data to define the true electricity demand, though it is certainly revealing of the great potential impact. Ultimately, this study concluded there are considerable possibilities to reduce both the energy consumption and carbon footprint through informed decisions regarding grow conditions, strategies, and the power source that drives production.
There are significant ecological benefits from approaching cannabis cultivation in an entirely different manner, through coexistence in natural environments suitable for compliant, outdoor harvests. Researchers report these benefits to include enhanced biodiversity with co-occurring crops, favorable influence on soil structure and typically lower nutrient level requirements compared to other major crops.2 Additionally, seasonal photoperiods may be utilized to drive production, reducing energy demand. Certain geographic locations allow for dry farming techniques, in which little to no additional water is required throughout crop growth, further reducing dependence on natural resources. Environmentally conscious organizations are developing principles and best practices for creating sustainable, regenerative cultivation of high-quality products.3,4 A central principle is polyculture, which involves the simultaneous cultivation or implementation of several crops or kinds of animals. These diverse systems create opportunity for localized, closed loop nutrient cycling among farm production
and relaxes dependence on inputs from the marketplace. A fundamental practice is Hügelkultur, a horticulture technique designed to intentionally allow wood debris and other compostable plant biomass materials to naturally decay in a mound for later use as a raised bed for crop production. These biodynamic strategies can improve both nutrient cycling and diversity of the soil microbiome over time, which can lead to healthier ecosystems overall. The principles of regenerative agriculture may even be applied to indoor, controlled settings for crop production through the form of no-till, living soils which can be built and maintained through similar processes. Providing cultivators educational opportunities for better understanding regenerative principles and best practices yields a method for improving the environmental impacts associated with cannabis production.
Existing regulatory framework has addressed many environmental concerns that researchers, activists and growers alike have considered, especially the maintenance of environmental integrity.5 These include potential effects on sensitive ecosystems due to nutrient runoff, water diversion, and introduction of contaminants. The compliant market is largely devoid of these negative impacts due to the quality systems in place by state law. By incorporating regenerative, sustainable practices, cultivation may positively impact environments. Education of these practices for industry operators is crucial to protecting the integrity of the environment. As cannabis cultivation is more widely recognized by the public as agriculture, essential research, both fundamental and applied, will help define critical aspects of both agronomy and plant physiology. Areas of focus include determining optimal growth rate conditions, identifying strategies for minimizing irrigation and chemical application, defining ideal agronomic systems to reduce waste stream contamination, measuring plant volatiles emission rates at different developmental stages, and quantifying risk to workers exposed to conditions at various cultivation sites. Fulfilling these open areas of research will advise environmental policy decisions pertaining to the growing sector of cannabis agriculture. To create long-term solutions for cannabis cultivation, incentivizing best practices through regulatory framework improvements will aid growers in reducing potential impacts on the environment.
1. Ashworth, K., & Vizuete, W. (2017). High Time to Assess the Environmental Impacts of Cannabis Cultivation. Environmental Science & Technology, 51(5), 2531–2533. doi:10.1021/acs.est.6b06343
2. Piotrowski, S., Carus, M. (2013). Ecological Benefits of Hemp and Flax Cultivation and Products. Nova Institut.
3. “Pure Farmer Blog.” Pure Farms RSS, http://dempurefarms.com/.
4. “Sun Earth.” Sun Earth, https://sunandearth.org/.
5. Butsic, V., & Brenner, J. C. (2016). Cannabis (Cannabis sativa or C. indica) agriculture and the environment: a systematic, spatially-explicit survey and potential impacts. Environmental Research Letters, 11(4), 044023. doi:10.1088/1748-9326/11/4/044023