Overview of Hemp Flour, Fiber, and Oilseed Production in Russia
For effective crop production development, it is essential to maintain a balanced crop rotation, which helps improve soil quality and control its phytosanitary condition. In this context, hemp—a once-forgotten crop that was widely cultivated in the Kurgan region in the 19th and early 20th centuries—has regained interest.
Hemp is a crucial industrial crop, serving as a raw material for thousands of products, including fiber, textiles, oil, paper, and medicines. Hemp oil is especially valued as a source of essential unsaturated fatty acids, and hemp fiber (tow) is also significant.
History and Breeding of Hemp in Russia
Russian hemp breeding (Cannabis sativa L.) has gone through several stages:
- Development of dioecious varieties with high fiber content
- Creation of high-yielding monoecious varieties
- Breeding of productive, non-narcotic varieties
Each stage resulted in new varieties with improved quantitative and qualitative traits, meeting the needs of processing industries. By the late 1990s, breeding was concentrated in three centers: the Krasnodar Research Institute of Agriculture (southern dioecious hemp), the Penza Research Institute, and the Chuvash Research Institute (central Russian monoecious hemp). Currently, breeding continues in Krasnodar and Penza.
Hemp Cultivation Conditions and Challenges
Hemp has a wide geographic range and can grow in active temperature ranges from 900 to 4000°C. In the Kurgan region, the annual sum of active temperatures is 2300–2350°C. This adaptability results in a wide variety of geographic forms with different biological and morphological traits.
Despite its value, hemp is barely cultivated in the Kurgan region today. According to the Kurgan Department of Agriculture, only 50 hectares were sown in Makushinsky and 8 hectares in Tselinny districts in 2021. The main reasons are lack of awareness, absence of adaptive cultivation technology, and incomplete information on documentation requirements.
Research on Hemp Cultivation in the Kurgan Region
From 2014 to 2016, initial field trials were conducted to develop effective cultivation techniques for monoecious hemp. The research aimed to:
- Assess the growth and development potential of cultivated hemp in the Kurgan region’s climate
- Determine optimal sowing times
- Evaluate the phytosanitary status of hemp fields
- Assess the possibility of producing high-quality seeds
- Evaluate the potential for producing oil with good fat content and low acidity
- Assess the potential for producing high-quality fiber
Two dual-purpose hemp varieties (for seed and fiber)—Rigs and Diana, bred by the Chuvash Research Institute—were studied. Experiments were conducted at LLC “Rus” in Makushinsky district. The results showed that the region’s climate is optimal for hemp growth. Hemp requires fertile soils and produces stable oilseed yields with plant heights of 200 cm or more on leached chernozems with high moisture retention.
Early sowing times are optimal for quality oilseed production. Fusarium (Fusarium oxysporum) is a major threat, causing root rot and seed wilt. Gray and white mold also cause significant damage, especially in wet weather during the second half of the growing season.
Despite challenging weather in 2014, hemp plants produced high-quality seeds, which were used in subsequent years. The harvested seeds yielded high-quality edible oil, even in unfavorable years, with high oil content and low acidity.
Stems of the studied varieties contained 28–32% fiber and 40–50% cellulose. Processing was done on a flax retting line, which proved inadequate for hemp; specialized hemp retting equipment is needed.
It was found that hemp is best grown in a separate crop rotation.
Further Research and Technological Improvements
In 2017, multi-factor experiments were conducted at LLC “Engineering and Production Center ‘Profservice'” in Makushinsky district using the Surskaya variety. The studies examined the effect of seeding rates on plant height, technical stem length, inflorescence length, stem diameter, seed oil content, oil yield, and total fiber content. Weed control was tested using a tank mix of Lontrel Grand and Furore Super. The effect of mineral fertilizers (azofoska) was also studied, applied before sowing at a rate of N60P60K60.
Sowing took place on May 16 in well-prepared soil, with harvest at full maturity (September 24–29). Results showed that higher seeding rates reduced stem diameter and height but increased total fiber content (25.1–32.9%), with the highest at 2.5 million viable seeds per hectare. Seed oil content ranged from 30.4% to 32.6%, decreasing with higher seeding rates. The highest oil content was at 1.7 million viable seeds per hectare, with full mineral fertilization and weed control. Thousand-seed weight increased with more space per plant, ranging from 15.6 to 18.1 g, highest with full mineral fertilization.
Variety Trials and Cellulose Quality
In 2020, trials continued with Vera and Nadezhda varieties (Penza Research Institute). The main goal was to study the effect of seeding rate and row spacing on plant survival. Laboratory tests measured cellulose yield, alpha-cellulose content, and residual lignin in technical hemp samples. The best delignification was observed in samples grown with wide-row sowing, but alpha-cellulose content was higher in samples from standard row sowing. For the Vera variety, standard row sowing was preferable for target product yield.
The Nadezhda variety grown with standard row sowing had the highest cellulose quality, with alpha-cellulose content 1.7% higher than Vera. Residual lignin content was similar between the two. Overall, alpha-cellulose content was higher in samples from standard row sowing, while residual lignin was lower in wide-row samples. Cellulose yield was similar across all samples (33.5–35% for standard row, 33.9–34.5% for wide-row). The best cellulose quality was from Nadezhda in standard row sowing, with 92.9% alpha-cellulose.
Economic Efficiency of Hemp Production
The economic efficiency of hemp seed, oil, cake, and flour production was assessed. Profitability increases with higher planned yields. At 0.30 t/ha oilseed yield, production is unprofitable; at 0.80 t/ha, profitability reaches nearly 130%. For oil and cake production, seed oil content scenarios of 28%, 31%, and 34% were analyzed. The most profitable was oil and cake from seeds with the highest oil content (over 90% profitability).
Hemp flour is a valuable food product, containing three times more protein than wheat or rye flour, and higher levels of calcium and magnesium. It has twice the lipids, 7.2 times more fiber than wheat flour, and three times more than rye flour, with four and 2.5 times more ash, respectively. It is also richer in minerals like calcium, magnesium, and iron. Its energy value is 290 kcal. The calculated profitability of hemp flour production was 13%.
Hemp Flour in Bread Production
Research was also conducted to develop a recipe for wheat bread using first-grade flour with a 5% functional hemp flour additive. The physical and chemical properties of the bread were tested for compliance with GOST R 58233-2018 “Wheat Flour Bread. Technical Specifications.” The sample met all requirements: moisture (41.1% vs. max 45%), acidity (0.9°N vs. max 3.0°N), and porosity (77% vs. min 65%). The economic efficiency of bread production with hemp flour was high, with profitability at 58.3%.
Conclusions
Long-term research has produced reliable results and refined hemp cultivation techniques. Five technical hemp varieties—Diana, Rigs, Surskaya, Vera, and Nadezhda—were tested, and their cultivation technologies were developed.