Hemp Production Research Articles

Optimizing Industrial Hemp Production with Dr. Josh Freeman

Optimizing Industrial Hemp Production with Dr. Josh Freeman

The reintroduction of hemp in the USA: a content analysis of state and tribal hemp production plans

BackgroundThe reintroduction of Cannabis sativa L. in the form of hemp (< 0.3% THC by dry weight) into the US agricultural sector has been complex and remains confounded by its association with cannabis (> 0.3% THC by dry weight). This has been further exacerbated by inconsistent hemp regulations in the US since the 2014 Farm Bill’s reintroduction.MethodsA content analysis was performed to analyze the terms and definitions presented by state and tribal hemp production plans, the USDA Hemp producer license, and the 2014 state pilot plans. A total of 69 hemp production plans were analyzed.ResultsResults suggest significant discrepancies between hemp production plans, which have been exacerbated by extending the 2014 Farm Bill language into the 2018 Farm Bill timeframe.ConclusionsFindings from this study point to areas in need of uniformity and consistency as the regulatory framework is modified and provides a starting point for change for federal policymakers. The results may also be useful to companies attempting to market products across state boundaries. Suggestions for how to mitigate these inconsistencies are provided based on the content analysis findings.

Are adverse effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?

Cannabidiol (CBD)-containing products are widely marketed as over the counter products, mostly as food supplements. Adverse effects reported in anecdotal consumer reports or during clinical studies were first assumed to be due to acid-catalysed cyclization of CBD to psychotropic Δ 9tetrahydrocannabinol (Δ 9-THC) in the stomach after oral consumption. However, research of pure CBD solutions stored in simulated gastric juice or subjected to various storage conditions such as heat and light with specific liquid chromatographic/tandem mass spectrometric (LC/MS/MS) and ultra-high pressure liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC-QTOF) analyses was unable to confirm THC formation. Another hypothesis for the adverse effects of CBD products may be residual Δ 9-THC concentrations in the products as contamination, because most of them are based on hemp extracts containing the full spectrum of cannabinoids besides CBD. Analyses of 362 hemp-based products of the German market (mostly CBD oils) confirmed this hypothesis: 39 products (11%) contained Δ 9-THC above the lowest observed adverse effect level (2.5 mg/day). Hence, it may be assumed that the adverse effects of some commercial CBD products are based on a low-dose effect of Δ 9-THC, with the safety of CBD itself currently being unclear with significant uncertainties regarding possible liver and reproductive toxicity. The safety, efficacy and purity of commercial CBD products is highly questionable, and all of the products in our sample collection showed various non-conformities to European food law such as unsafe Δ 9-THC levels, hemp extracts or CBD isolates as non-approved novel food ingredients, non-approved health claims, and deficits in mandatory food labelling requirements. In view of the growing market for such lifestyle products, the effectiveness of the instrument of food business operators' own responsibility for product safety and regulatory compliance must obviously be challenged, and a strong regulatory framework for hemp products needs to be devised.

Nitrogen fertilization impact on hemp (Cannabis sativa L.) crop production: A review

AbstractRegained interest in hemp cultivation has created opportunities and challenges, especially regarding crop management, for example, fertilizer application rate. Most of the literature on nitrogen (N) management in hemp production is from Asia and Europe, with more established cropping systems than in North America. Through our review, we found evidence that N fertilizer has a noticeable positive impact on basic crop morphology and physiology parameters, or at least the crop responds to such infield fertilizer applications. Some physiological parameters that show positive response include photosynthetic pigments, N and nitrate concentration, and water use efficiency. N fertilizer has been demonstrated to increase stem and fiber yield but reduce fiber quality. Increasing N also appears to increase seed yield and protein content. Both excess and low rates of N fertilizer are detrimental to floral hemp. There is little evidence that Δ9‐tetrahydrocannabinol concentration is more affected by N fertilization than genetics. The impact of fertilizer source and timing remains a critical area for research. There is still a need for research on developing a sustainable nutrient management program for hemp.

Identification of Characteristic Parameters in Seed Yielding of Selected Varieties of Industrial Hemp (Cannabis sativa L.) Using Artificial Intelligence Methods

Currently, there is a significant increase in interest in hemp cultivation and hemp products around the world. The hemp industry is a strongly developing branch of the economies of many countries. Short-term forecasting of the hemp seed and grain yield will provide growers and processors with information useful to plan the demand for employees, technical facilities (including appropriately sized drying houses and crop cleaning lines) and means of transport. This will help to optimize inputs and, as a result, increase the income from cultivation. One of the methods of yield prediction is the use of artificial intelligence (AI) methods. Neural modeling proved to be useful in predicting the yield of many plants, which is why work was undertaken to use it also to predict hemp yield. The research was carried out on selected, popular hemp varieties—Białobrzeskie and Henola. Their aim was to identify characteristic factors: climatic, cultivation and agrotechnical, affecting the size and quality of the yield. The collected data allowed the generation of Artificial Neural Network (ANN) models. It has been shown that based on a set of characteristics obtained during the cultivation process, it is possible to create a predictive neural model. Modeling using one output variable, which is seed yield, can be used in short-time prediction of industrial crops, which are gaining more and more importance.

Characterization of aerosols from hemp-derived pre-roll joints

Objective Availability and consumer use of hemp products is rapidly increasing, but little work has been done to assess aerosol emissions of hemp pre-rolls. The objective of this research was to characterize the aerosol of pre-rolled joints from hemp material enriched for production of cannabigerol (CBG) that were smoked on a test system mimicking human use patterns. Materials and methods Aerosol emissions were collected and analyzed using glass microfiber filters and charcoal cartridges. The aerosol was screened for nine phytocannabinoids and 19 terpenes. Results Three phytocannabinoids (CBG, cannabichromene (CBC), and delta-9-tetrahydrocannabinol (THC)) were detected and quantified at a mean (SD) concentration of 19.4 (4.7), 0.48 (0.01), and 0.40 (0.04) mg per pre-roll, respectively. Five terpenes ((–)-α-bisabolol, (–)-guaiol, β-caryophyllene, nerolidol, and α-humulene) were detected and quantified at an average concentration of 352.7 (112.0), 194.3 (66.4), 106.0 (50.4), 28.3 (9.3), and 27.7 (11.2) µg per pre-roll, respectively. Particle size distribution testing via aerodynamic particle sizer and inertial impactor showed that average size of emitted aerosols was 0.77 (0.0) and 0.54 (0.1) µm, respectively. Conclusions This study describes methodology for characterization of cannabinoid and terpene dose in emitted aerosols and aerosolization efficiency from hemp pre-rolls. It also presents these data for one of the marketed products.

A recent Cannabis pollen increase on the Iberian Pyrenees

The continuous, varved and absolutely dated sedimentary record of Lake Montcortès (Iberian Pyrenees) has provided evidence for a distinct and characteristic 20th century (1980s) increase in Cannabis pollen (20C) that persists today. This event was coeval with the geographical shift of the hemp production center in the Iberian Peninsula from east to northeast (where Lake Montcortès lies), which was accompanied by a significant production increase. This increasing trend was fostered by the renewed interest of the paper industry in hemp and was promoted by the onset of European Union subsidies to hemp cultivation. Illegal cannabis crops could have also contributed to the Cannabis pollen increase, but sound evidence is still lacking. These preliminary conclusions should be reinforced by increasing the resolution of the current palynological record and modeling the dispersal of Cannabis pollen around the Montcortès region. More similar high-resolution records are needed to verify the geographical extent of the 20C event. Additionally, Lake Montcortès varved sediments are proposed as a suitable candidate to characterize the onset of the “Anthropocene” epoch (mid-20th century), as currently defined by the Anthropocene Working Group.

Qualitative Analysis of Industrial Hemp Production, Markets, and Sustainability in North Carolina, United States

The North Carolina hemp industry has fallen short of its projected success despite its potential economic benefits and opportunities for farmers. The floral hemp sector specifically has been struggling due to excessive production and decreasing prices. The objective of the research was to examine the experiences and obstacles faced by early adopters and stakeholders of the hemp industry in NC. Through structured focus group discussions and interviews, data were collected and analyzed to gain insight into the industry’s direction. The results revealed that many floral hemp farmers have abandoned the crop because of financial setbacks, leading to a reduced interest in cultivation compared to five years prior. The floral hemp industry’s rapid growth and decline have tempered farmers’ expectations of the crop’s potential. The findings will provide a foundation for further research into NC’s hemp production and economy, enabling the provision of necessary information and extension services for profitable hemp farming in the state.

The Sustainability of Industrial Hemp: A Literature Review of Its Economic, Environmental, and Social Sustainability

Industrial hemp is a versatile, sustainable plant with several applications of its various forms, including fiber obtained from hemp stalks, food obtained from hemp seeds, and oil obtained from hemp flowers and seeds. Industrial hemp has the potential to offer a solution to the crisis of climate change, since it is a viable energy source that satisfies the three pillars of sustainability, namely economy, environment, and society. Although industrial hemp has been growing as an agricultural commodity in different parts of the world for decades, its production was banned until recently in the U.S. because of its association with marijuana. We conducted a literature review to explore some of the reasons why the U.S. production of industrial hemp has increased significantly since the ban was lifted. Our findings revealed that hemp’s rapidly increasing popularity in the U.S. since 2018 can be attributed, in part, to its sustainability potential (defined as the potential to positively impact the sustainability of products, using hemp as a renewable raw material). This study fills a gap in the knowledge regarding hemp’s potential as a sustainable crop.

A One Health perspective on comparative cannabidiol and cannabidiolic acid pharmacokinetics and biotransformation in humans and domestic animals

The goal of pharmacokinetic (PK) studies is to provide a basis for appropriate dosing regimens with novel therapeutic agents. With a knowledge of the desired serum concentration for optimum pharmacological effect, the amount and rate of drug administration can be tailored to maintain that concentration based on the 24-hour PK modeling (eg, every 24 hours, every 12 hours) to achieve therapeutic ranges. This dosing and PK information are tailored to maintain that concentration. Typically, these optimum serum concentrations pertain across species. Single-dose PK modeling provides fundamental parameters to suggest dosing regimes. Multiple-dose PK studies provide information on steady-state serum levels to assure that desired therapeutic levels are maintained during chronic administration. Clinical trials using dosing suggested by these PK determinations provide proof that the compound is producing the desired therapeutic effect. A number of PK studies with cannabinoids in humans and domestic animals have been conducted with the goal of determining appropriate clinical use with these plant-derived products. The following review will focus on the PK of cannabidiol (CBD) and the lesser-known precursor of CBD, cannabidiolic acid (CBDA). Although Δ9-tetrahydrocannabinol (THC) has profound pharmacological effects and may be present at variable and potentially violative concentrations in hemp products, PK studies with THC will not be a major consideration. Because, in domestic animals, hemp-CBD products are usually administered orally, that route will be a focus. When available, PK results with CBD administered by other routes will be summarized. In addition, the metabolism of CBD across species appears to be different in carnivorous species compared with omnivorous/herbivorous species (including humans) based on current information, and the preliminary information related to this will be explained with the therapeutic implication being addressed in Currents in One Health by Ukai et al, JAVMA, May 2023.

Cultivar and management effects on industrial hemp yields in Wisconsin

AbstractAfter decades of heavy regulation, growers across the United States were able to begin growing industrial hemp (Cannabis sativa L.) again in 2014. The 2014 and 2018 Farm Bills made it legal for research and production to resume and removed hemp from the list of controlled substances. Because of the long prohibition of hemp production, many questions surrounding best management practices still exist. In 2019 and 2020, studies were conducted in Arlington and Chippewa Falls, Wisconsin to evaluate the effects of cultivar, seeding rate, and nitrogen rate on hemp yield. Two cultivars (X‐59 and CRS‐1), seeded at three seeding rates (22, 34, and 45 kg ha−1) and three nitrogen rates (0, 67, and 134 kg ha−1), were evaluated. At Arlington, nitrogen did not impact fiber yield; however, an interaction among cultivar, seeding rate, and nitrogen rate effected grain yield. At Chippewa Falls, fiber yield increased by 20% when nitrogen rate increased from 0 to 67 or 134 kg N. Similarly, grain yield increased by 52% when the nitrogen rate increased from 0 to 67 or 134 kg ha N. The effect of seeding rate alone was highly variable with no consistent pattern on response variables measured. Therefore, the overall effect of nitrogen rate was more consistent than the effect of seeding rate on response variables measured. Ultimately, management recommendations will be dependent on local conditions; however, hemp does respond to the addition of nitrogen fertilizer.

Industrial Hemp (Cannabis sativa L.) Agronomy and Utilization: A Review

Currently, there are increased interests in growing grain and fiber hemp (Cannabis sativa L.) as well as in large-scale hemp products. Cannabis has been grown/utilized for thousands of years as a fiber, grain, and drug/medicinal plant. However, the strict control of cannabis cultivation to combat illegal use, the spread of new yarns and oilseeds, and the advent of cheap synthetic fibers caused a decreased/eliminated hemp production. Hemp has been banned in most of the world for more than seven decades; it missed out on the Green Revolution and the adoption of new technologies and varieties, creating a knowledge gap. After the 2014 and 2018 Farm Bill in the USA, hemp became legal and the land grand universities launched research programs. The ability to utilize the entire plant for multiple purposes creates opportunity for the market to value hemp products. Hemp production technology varies depending on the type of hemp cultivated (grain, fiber, or cannabinoids), soil characteristics, and environmental factors. Hemp has the potential to be a very sustainable and ecologically benign crop. Hemp roots have a significant potential for absorbing and storing heavy metals such as lead, nickel, cadmium, and other harmful substances. In addition, hemp has been proven to be an excellent carbon trap and biofuel crop. Hemp has the ability to successfully suppress weeds, and it is generally regarded a pesticide-free crop. The purpose of this paper is to examine historic and recent industrial hemp (grain and fiber) literature, with a focus on hemp agronomy and utilization.

Microbial consortium inoculant and rock mineral fertiliser differentially improved yield and nutrient uptake of industrial hemp (Cannabis sativa L.) varieties

Industrial hemp (Cannabis sativa L.) production is attracting widespread attention in agriculture but is facing cultivation challenges in nutrient-poor sandy soils. The crop has a fibrous deep taproot system known to have a good association with the rhizosphere soil microbiome. However, there are few reports on incorporating microbial inoculants with or without rock mineral fertilisers to facilitate nutrient mineralisation and stimulate growth of industrial hemp. To test whether microbial consortium inoculant with or without fertiliser improves the growth and yield of industrial hemp by increasing root biomass and nutrient uptake, we assessed the impact of microbial inoculant and rock mineral fertiliser in two hemp varieties (Morpeth and Han FNQ). The experiment was conducted in a randomised complete block design with four treatments: control (CTRL), consortium microbial inoculum (MI), rock mineral fertiliser (MF) and combined microbial inoculum and mineral fertiliser (MI+MF). Plants were grown in compost in a controlled-environment phytotron and harvested 30 and 70 days after sowing (DAS). Han FNQ had higher root dry weight, shoot length, leaf chlorophyll, Mn and Zn uptake than Morpeth at 30 DAS, and Han FNQ in the MI+MF treatment also had greater root volume than Morpeth in all treatments at 30 DAS. At 70 DAS, Morpeth had a higher seed yield than Han FNQ and Morpeth in the MI treatment had greater shoot and root dry weight, leaf chlorophyll, root length and volume, and higher uptake of all macro- and micronutrients in shoots and seeds than Han FNQ in all treatments. These findings suggest that the resource stoichiometry and trade-balance model in plant-microbes symbiosis govern the effectiveness of MI on industrial hemp. The application of MF and the initial nutrients abundance in the compost might suppressed MI activity at 30 DAS whereas, the nutrient limiting condition at 70 DAS might triggered MI activity and symbiotic trade of nutrients between plant and microbes which facilitated root growth and nutrient uptake particularly, in the variety Morpeth.

What factors make consumers in the USA buy hemp products? Evidence from Nielsen consumer panel data

This study aims to identify critical consumer-demographic characteristics associated with the consumption of products containing hemp and investigate their effect on total expenditure in the USA. To estimate the likelihood of market participation and consumption level, the Heckman selection model is employed utilizing Nielsen consumer panel data from 2008 to 2015. Using a Heckman selection model, this study finds that socio-demographic characteristics, especially income, age, and education, play an important role in explaining purchases of and demand for different categories of hemp products. Noteworthy is the finding that the role of the age of the household head is mixed with respect to consumption decisions and consumption level across the products. In most cases, higher education and income households are more likely to buy hemp products, and those are associated with significantly higher consumption levels. The hemp products used in this study are made of hemp seeds, and our findings show that the hemp seed market could be segmented based on the forms. Results provide a basic understanding of a consumer profile and overall hemp market that has had double-digit growth over the last six years. As the industry continues to move forward, policymakers will need a deeper understanding of the factors driving the industry to create regulations supporting the development of the hemp industry.

Multi-environment assessment of a yellow hemp (Cannabis sativa L.) cultivar’s eco-physiology and productivity under varying levels of nitrogen fertilisation

Yellow stalked cultivars of hemp (Cannabis sativa L.) were reported to have a superior fibre processability than green cultivars, but the effects of the yellow trait on productivity and ecophysiology of hemp remain unexplored. It is hypothesised that yellow stalked cultivars are characterised by a low Nitrogen Uptake Efficiency. Three field scale experiments involving a yellow cultivar ('Fibror 79') and a green one ('Futura 75') grown under varying levels of nitrogen fertilisation were conducted in Northern Italy and in Wales, to investigate the effects of the yellow trait on hemp productivity and eco-physiology. The results showed that 'Fibror 79' displays a slightly lower biomass productivity than 'Futura 75' under nitrogen-limiting conditions, owing to lower Leaf Area Index and light interception capacity during the early growth phase, and potentially due to a lower radiation use efficiency. However, the productivity was not significantly different between cultivars under non-limiting nitrogen conditions. The Nitrogen Uptake Efficiency did not differ between the two cultivars, which failed to support the hypothesis of this work. Instead, Nitrogen Use Efficiency and Nitrogen Utilisation Efficiency were significantly higher for 'Futura 75' than for 'Fibror 79' under nitrogen-limiting conditions. 'Futura 75' appeared better suited than 'Fibror 79' for dual- and multi-purpose production in Italy, while the reverse was true in Wales. 'Fibror 79' better suits a strategy of single-use fibre production owing to its higher bast fibre content and fibre yield.

Hemp-Based Sustainable Slippery Surfaces: Icephobic and Antithrombotic Properties.

With the passage of the 2018 Farm Bill that removed hemp from the Controlled Substances Act altogether, production of hemp is experiencing a renaissance. Building on this revival and re-emergence of hemp, we designed and fabricated hemp-based sustainable and robust slippery surfaces by coating hemp paper with beeswax and subsequently infusing it with hemp oil. A wide variety of aqueous liquids and beverages easily slide on our hemp-based sustainable slippery surfaces, without leaving a trace. We also fabricated hemp-based sustainable slippery surfaces using different textured metals. Our hemp-based sustainable slippery metal surfaces display good icephobic and antithrombotic properties. With these attributes, we envision that our hemp-based sustainable slippery surfaces will pave the path to more safe, non-toxic, and biodegradable or recyclable slippery surfaces for applications in food packaging, anti-icing or de-icing coatings, and antithrombotic medical devices.

Hemp seed-based food products as functional foods: A comprehensive characterization of secondary metabolites using liquid and gas chromatography methods

Despite hemp has a long history as food, in the last years the interest in cannabis cultivars, including new varieties, requires a deeper investigation of hemp seed-based food products as a precious source of biomolecules. In the present work, a comprehensive characterization of the minor components occurring in hemp seed-based food products i.e. oil, flour and flour by-product, is reported. For this goal, volatile (i.e. terpenes, hydrocarbons, furans and ketones) and non-volatile (i.e. tocopherols, cannabinoids and phenolic compound) metabolites were investigated by means of different chromatographic techniques. HPLC in combination with PDA, fluorescence, and MS detection was employed to analyse non-volatile fraction. Furthermore, GC coupled with FID and MS detectors were used for the analysis of volatiles and unsaponifiable compounds, the latters after conversion into more volatile trimethylsylil derivatives. Terpenes represented the most abundant compounds among volatiles. A total of 58 compounds belonging to the unsaponifiable matter was identified only in hempseed oils. Among tocopherols, γ-tocopherol was quantified at the highest level. Phenols and cannabinoids were also investigated, and a total of 52 compounds were identified and quantified. To the best of our knowledge, this is the first study providing a thorough chemical characterization of minor fraction of hemp products.

Cannabis sativa: Release of Volatile Organic Compounds (VOCs) Affecting Air Quality

This review paper highlights about the emission of volatile organic compounds (VOCs) of Cannabis plants. Volatile organic compounds (VOCs) are a large group of chemicals harmful to human health that are readily released into the atmosphere and participate in atmospheric photochemical reactions. Floral Volatile organic compounds (VOCs) are often involved in defence and pollinator attraction. Cannabis cultivation and consumption may lead to additional environmental impacts. Studies found out that Cannabis plants emit a significant amount of biogenic volatile organic compounds (BVOCs) which could cause indoor air quality issues. Indoor Cannabis cultivation is energy-consuming, mainly due to heating, ventilation, air conditioning, and lighting. Energy consumption leads to greenhouse gas emissions. Common compounds to all the tested hemp cultivars include β-myrcene, ϒ-caryophyllene, α-pinene, β-pinene and limonene, reflecting species specificity in the emission of these compounds. β-Myrcene was the most abundant compound in most of the outside hemp cultivars. The terpenes had an earthy musky, and fruity smell may contribute to the odour in Cannabis samples at the vegetative stage, flowering stage, and drying/curing stage. All hemp cultivars are the prolific emitters of terpenoids. The oxidation of highly reactive Biogenic Volatile organic compounds (BVOCs) from Cannabis plants can lead to the formation of ozone and secondary Volatile organic compounds (VOCs) (e.g., formaldehyde and acrolein). In hemp production, considerable odorous emissions occur during field retting. However, more research is needed to address how outdoor air quality is influenced by Cannabis cultivation facilities (CCFs) emissions.

Producers marketing a novel crop: a field-level view of hemp market channels

Abstract We assess emerging relationships between production decisions and market channel selection among a small sample of hemp growers (22) in Colorado and Kentucky using qualitative interviews. We found producers differences by market channel, product and state. For instance, producers who relied on intermediated marketing strategies cultivated more acres on average and used fewer distinct market channels and strategies than those relying on direct markets. Product differences were found regarding processing, storage and perishability. Respondents identified four factors critical to their choice of market channels for their hemp products: research, profitability, trust and knowledge. The findings can help inform public and private decision-making regarding best hemp marketing practices and future needs of the hemp industry.

Fusarium Species Recovered from Postharvest Hemp Materials from Kentucky Fields

As hemp becomes established as a commodity in the United States, continued cultivation demands a greater understanding of the pathogens that affect the consumable portions, such as flowers and grain. Four Fusarium spp. have been confirmed to cause Fusarium head blight on hemp in Kentucky. Several Fusarium species, including F. graminearum, that are known to produce mycotoxins have been confirmed pathogenic on hemp. Fusarium mycotoxins are regulated in grains used for human and animal consumption. Determining which Fusarium species infect hemp is the first step to producing safe material. Although field disease is under investigation, there have been no studies regarding stored hemp. Harvested and stored floral material for production of cannabidiol (CBD) were collected from seven Kentucky producers from 2019 and 2020 harvests. The material was screened using a Fusarium-selective medium and DNA sequencing. At least 12 different species were isolated, most from the Incarnatum-equiseti species complex (75.6%). Species from the Sambucinum (16.3%), Oxysporum (0.8%), Fujikuroi (5.7%), and Solani (1.6%) species complexes were also identified. Additional research is essential to determine whether these Fusarium species are pathogenic or saprophytic and whether they can produce toxins dangerous for humans and animals. Such information is crucial to determine how to store hemp, manage infected material, and promote successful production of hemp products.