Hemp is known as a fiber plant for approximately 5000 years, and later as a medicinal plant. Its origin is from Middle Asia. It originate from the wild cannabis plant which was translated into cultivated plant. Hemp plant has more than 60 naturally occurring active components called cannabinoids. Cannabidiol (CBD) is one of these naturally-contained components in the hemp plant. Tetrahydrocannabinol (THC) is the most famous cannabinoid. CBD does not affect the same way as THC, which is best known as the psychoactive hemp component. The CBD has no such effect and does not affect on a different world experience and behavioral change like THC. THC is a psychoactive ingredient and will affect your brain, while the CBD won't. CBD is a non-psychotropic compound and numerous studies have shown that CBD even helps against abnormal THC effect that can cause anxiety or paranoia, while CBD has a completely opposite effect and potential for clinical usage in psychiatry. Cannabis plants are divided into two different types of a crops, known as hemp and marijuana. These two plants differ in their cannabinoid ratios but come from the same species of Cannabis sativa L.
Legal framework for hemp production
The production of industrial hemp in the Republic of Croatia is regulated by the Act on the Suppression of narcotic drugs abuse (NN 107/01, 87/02, 163/03, 141/04, 40/07, 149/09) and Ordinance on conditions for the cultivation of hemp, the method of poppy breeding and the conditions for possession and circulation of narcotic drugs in veterinary medicine (NN 18/12). It is permitted to grow industrial hemp (Cannabis sativa L.) for the purpose of producing food and feed. The content of the psychoactive substance tetrahydrocannabinol (THC) in the dry matter of the plant should not exceed 0.2%. In the type of Indian hemp, which is forbidden to sow in the Republic of Croatia, THC content ranges from 5-20%. Its purpose is limited in using for medical purposes and the production of narcotic drugs. Hemp can be grown only on the basis of the granted license for the cultivation of cannabis. Before the sowing of industrial hemp it is obligatory to submit a Request for permission to grow hemp to the Ministry of Agriculture.
Morphology and physiology
The root system is spiny and makes a thick underground root network. It can penetrate into the ground up to 2 m and in width up to 1.5 m. Of the totall weight of the plant the roots waste 8-10%, so it has a lower suction power. The root of female plants is better developed than the root of male plants. This is beacuse the male plants finish their vegetation earlier and the female plants after the fertilization feed the seed to its maturation, which requires more food and water. That is provided by stronger root system which have female plants. The stalk is upright, initially gentle and greasy, and later it gets hardener. It has intensive green color, covered with cocoon hair that later falls and leaves visible scars. The stalk is hollow, devided into nodies and internodes. The height of the stalk ranges from 50 cm to 6 m, depending on the area of production (in the north is low and high in the north), soil type, agrotechnics and breeding conditions. The stalk of male plants is slightly higher than the stalk of female plants. Of the total mass of the plant, it accounts for about 65%. The thickness is about 6 - 8 mm and the seedlings have a thick stalk several centimeters thick. At each node there are two opposing leaves, up to the upper third of the plant, from which they begin to separate in order to be thick in the flower area. Hemp is a dioecious plant which means that male flowers are on the male plants and female flowers on the female plants. The flowers are located on the top of a stalk and lateral branches and have longer flower buds. The male plants have grape shaped flowers. Female flowers have no stems, they are sitting.
The seed is two-leafed nut, roundish-shaped and flattened. Its surface is smooth and shiny and the colour is dark green, brown green, silver-gray with black primer. The weight of 1 000 seeds is about 20 g and a hectolitre weight is about 50 kg. Seed consists of a nut shell, seed shell, endosperm and germ. It is smaller, up to 2-3 mm in diameter and may be silvery to dark-brown or brown. By its chemical composition it contains between 25-38% oil, about 25% protein and a significant proportion of dietary fiber, vitamins and minerals.
1.Industrial hemp - Cannabis sativa subsp. sativa
2. Indian Hemp - Cannabis sativa subsp. indica
3. Ruderal hemp - Cannabis sativa var. ruderalis
In our conditions is grown industrial (ordinary) hemp, which is divided into European and East Asian. It is divided by geographic types that were created under the influence of climatic conditions and type of soil that changed the characteristics of hemp.
Agroecological conditions of cultivation
Normal germination is possible at a soil temperature of 7 ° C. In a phase with 1-2 leaf, it can withstand short-term frost up to -3 ° C. The optimum temperature for intense growth is between 20 and 25 ° C. For its growth hemp requires a lot of light. In good conditions the rapid growth of overground mass takes place in the first month of growth and development of hemp.The largest water needs are in the first 6 weeks of growth (up to the fourth parcel of leaves), when it begins to close the set. The next critical period is of 30 cm in height to the full flowering of male plants. Hemp grown for the seed should have enough water from the flowering to the amber. Storm rains can harm the stalk what results its fracture, less crops and difficult harvesting. The optimal air humidity for growth rises from 70 to 80%. Hemp is recommended to sow on the soils which are structural, medium-heavy, well drained and rich in nutrients (sandy-loamy, clay-sandy and alluvial with plenty of humus). Sowing on heavy cold soils with high groundwater levels should be avoided.Hemp responds to different soil fertility with different height of stalk. Successful growth requires a pH from 6 to 7.5, but not under the 5. It is susceptible to stagnant water, which can affect the lag in crop growth or decay. It is susceptible to stagnant water, which can affect the lag in crop growth or crop decay. There are no special requirements in crop rotation.Good precrops for hemp are potatoes, soy and legumes and some worse pungent grains, corn and sugar beet. Hemp tolorates monoculture for 2-3 years on fertile soils with a higher amount of nutrition, but increases the possibility of diseases and pests attacks.
Soil preparation and sowing
The main soil treatment sholud be done in autumn at a depth of 30-40cm. Closing the winter harrow with the harrows sholud be done in early spring. Soil preparation should be with seed harrow or combined machines. On solis which are weedy for many years it sholud be avoided to use soli-cutting machines for soil preparation. Hemp matches the principles of ecological agriculture because it does not require pesticides for its cultivation. Hemp works as a natural herbicide so it can suppress weeds well. It also has the ability to extract heavy metal from the soil, it protects the soil from erosion by its thick and deep roots and prevents the loss of groundwater. Hemp seeds have 20 to 30% less germinability in the field than what is shown by laboratory seed germination analyzes. Sowing should be done timely and in well-prepared soil with the processed and certified seed. Hemp is sown in the second half of March and early April with sowing machines. The fiber hemp is sown to a spacing of 10-12 cm. The density of the plant in the sowing area is 250-300 seedlings per square meter in order to obtain a crop of about 150-200 plants per square meter. The amount of seeds is 60 - 70 kg / ha. The hemp sown for seed production is in spacing of about 60 cm between rows and 20-30 cm in rows. Depth of sowing is 2 to 4 cm depending on whether it is lighter or harder soil. There is a risk of damage for young plants from frost in early sowing. Later sowing will result in shortening the vegetation and lower seed yield in case of drought. The sowing ground must be well prepared and sagging. It is recommended rolling after sowing in some cases.
Cultivation and fertilization
If a crust is formed it is necessary to suppress it with light or rotary harrows. In hemp for fiber we do not need to repress the weeds beacuse the hemp grows fast and chokes them. In the production of hemp seed 2/3 male plants should be removed when they are identified (when they develop flowers) and all are removed after fertilization. When the plant is in the phase of 3 pair of leaves it is necessary to do the soil adaptation with nutrients. In hemp seed production cultivation is necessary after the rain, when the soil is dry enough.
Fertilization should be done according to chemical analysis of the soil and feeding off the crop with the planned yield. On average fertile soils fertilization should be with 150 kg / ha of nitrogen, 120 kg / ha of phosphorus and 120 kg / ha of potassium. Hemp has a shorter vegetation so all the nutrients can be applied in deep processing and pre-soil preparation. A little more nitrogen is given in the basic processing and the rest in the soil preparation for sowing. It is good to use the urea because it has long action and does not wash away.
The problem in harvesting is that hemp plant is dioecious beacuse men's and women's plants grow and mature unequally. Male plants mature earlier so in the combine cultivation they are harvested first. Hemp grow for the seed is harvested when the largest seed amount is mature. The seed should be dried under 10% water. Hemp grown for fiber is harvested after fertilization (first half of August). Harvesting is done by special lawnmowers with lateral mowers. The stem must be drained, poured and tied into the beams (20 centimeter in diameter). They are left in the air and sun till complete dryness and then go to the processing factory.
The fiber from hemp can be separated:
Physically - from the wooden part of the stem is separated by steam or boiling water
Mechanical - by breaking stems and separating fibers with special machines
Chemical - fiber is separated by alkali and acid
Biological (wetting or maceration) - it is based on the decomposition of pectin substances that link fibers to the woody part of the stem, using microorganisms. It can be used in roasting (drying) in liquid or standing water or in specially designed pools, where water temperature (20 - 30 ° C) and maceration processes can be controlled. When the stem is immersed in water, it swells the pectin, cracks are formed, and the water penetrates into them and the fibers are disconnected. The water is released and the stems are washed and air dried when the process is completed. Dried stem is processed on the special machines and the fibers are cutted off the wooden part. Separated fiber goes to further processing.
Seed drying and storage
After harvesting the seed sholud be purified and dryed. The seed can not remain on the pile because mass and quality disturbance is occurring rapidly. Dried seed must not have a moisture content greater than 12%. Drying is done in driers with hot air at temperatures lower than 60 ° C. Well dried seed can be stored in bags or bulk in dry floor warehouses with ventilation capability. When stored in bulk, the stored seed layer should not be less than 30-40 cm long and with constant temperature control.
Usage and healing
The first records on the use of hemp in the treatment of malaria and constipation have been preserved in the herbarium of the Chinese Emperor Shen Nung in 2737 BC. Another well-known record where it is apparent that the Chinese knew its psychoactive properties is found in the Pharmacopoeia Pen Ching book from the first century BC. The plant was used in China for fiber and seeds 3000 years ago but its special importance was in paper production. Hemp have been used for many medical purposes: for treating headaches, toothache, anesthetics, anti-inflammatory drugs, antiparasitics, diuretics, in the treatment of skin infections and tuberculosis.
Hemp fiber is characterized by high strength, elasticity, longevity and water resistance and it is used for the production of ropes, ropes, sails, canvas, clothing and footwear, tents, tents, fishing nets, fire hoses and equipment, bags, horse coupling equipment etc. Male plants have a higher percentage of fiber and their fiber is better quality than the fiber of female plants. Hemp yields 250% more cotton fibers and up to 600% more fibers than flax on the same surface of the ground and is much stronger and more resistant. After getting the fibers remains woody part of the stem used for making paper, cellulose, insulating material and like firewood. From hemp we can get oil which is used in human nutrition beacuse hemp seeds have more than 30% of oil. Hemp oil has a specific green color due to its higher content of chlorophyll and its characteristic, nutty taste. There is almost an ideal ratio of essential fatty acids (ω-6: ω-3) of 2,5: 1 and its regular consumption can significantly influence the regulation of this relationship in our body. It is a rich source of tocopherols and sterols. Due to light drying the oil is used for producing paint and varnish and the seeds are used for poultry and like bird food.
Hemp seeds contain on average about 25% of nutritionally valuable proteins. Two major representatives are edestin and albumin, rich in essential amino acids and similar performances to the amino acid composition of egg whites and soy protein. Hemp proteins can be consumed in many ways. The easiest is directly from seed: minced, unminced, with or without shell. Another way is to use "hemp proteins" which are basically minced rests of the seed after the oil is compressed out of it. There is an increasing trend in the use of this product in athletic, vegetarian and vegan nutrition or in addition to preparing various bakery products or healthy snacks. Wooden part of the hemp stalk is used for paper making (cigarette paper, securities paper, Bible paper, greaseproof paper, special paper for painting, insulating tape for electric capacitors, special non-woven paper, filter paper, coffee filters and tea bags). Hemp fiber is also used for making the brake mechanism and the interior trim of the car.
Ground seed tea was used for healing urinary tract infection and like compress after insect bite and swelling. Also was used for diseases such as tonsillitis, fever, insomnia, warts and hair loss. Hemp seeds provide a range of health benefits, encourage healthy weight loss, reduce bad cholesterol and regulate blood pressure, improve circulation and immunity, increase energy, regulate optimal blood sugar control and many more. They are a great source of essential fatty acids and can be used in countless ways.
Obranović, M., Ozmec, N., Hladno prešana ulja (Praktični savjeti za zdravlje i ljepotu), Biblioteka čudotvorne namirnice, Planetopija, 2015.
Obranović, M., Ozmec, N., Konoplja (Praktični savjeti za zdravlje i ljepotu), Biblioteka čudotvorne namirnice, Planetopija, 2014.