Industrial hemp and its potential (original) (raw)
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Agriculture, 2020
Hemp (Cannabis sativa L.) is an emerging high-value specialty crop that can be cultivated for either fiber, seed, or cannabidiol (CBD). The demand for hemp and its products has been consistently on the rise in the 21st century. The United States of America (USA) has reintroduced hemp and legalized its production as an agricultural commodity through the 2018 Federal Farm Bill. Although there is a renewed interest in the adoption of hemp due to the emerging market, its production in the United States (US) remains limited partly because of unclear agronomic guidance and fertilization recommendations. This review article provides information on the current agronomic management practices that are available in the literature and identifies the future research needs for cultivating this multipurpose crop to address the growing market demands. Hemp production could be beneficial if managed properly. Hemp fertilizer requirements vary in accordance with the type of hemp grown (seed, fiber, or CBD), soil, environmental conditions and requires a wide range of macro-and micronutrients. Integrating management practices in hemp cultivation intended to build soil health is promising since the hemp cropping system is suitable for crop rotation, cover cropping, and livestock integration through animal waste applications. Hemp also has significant environmental benefits since it has the potential to remediate contaminated soils through phytoremediation, convert high amounts of atmospheric CO 2 to biomass through bio-sequestration, and hemp biomass for bioenergy production. This review identifies that most of the agronomic research in the past has been limited to hemp fiber and, to some extent, hemp seed but not CBD hemp. With the increase in the global markets for hemp products, more research needs to be conducted to provide agronomic guidelines for sustainable hemp production.
Industrial Hemp (Cannabis sativa L.) Agronomy and Utilization: A Review
Agronomy
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...
Open Agriculture
With the expanding hemp cannabidiol (CBD) industry in the United States, information on fertilizer recommendations for optimal production under field conditions is deficient in the literature. This study evaluates the effects of nitrogen (N) fertilization on bud biomass and CBD yield of two high-yielding CBD hemp varieties (Spectrum and Therapy) under field conditions. Four application rates of N fertilization (0, 56, 112, and 224 kg N ha−1) were supplied using 2 commercially available N fertilizers. Fresh bud biomass, dry bud biomass, and CBD yield (g plant−1) increased quadratically with N fertilization rates, with optimum rates between 140 and 190 kg N ha−1. When pooled across varieties, the tissue N concentration was linearly related to the fresh bud biomass, dry bud biomass, and CBD yield. Our findings show that N fertilization can affect CBD yield under field conditions. The resulting effect of N fertilizer rates on these varieties could serve as a preliminary guide for CBD he...
Industrial Crops and Products, 2019
The last climate change forecasting and the water scarcity scenarios in many semi-arid agricultural areas worldwide, such as the southern Spain, are promoting changes in the crop pattern of irrigated agriculture, being introduced new species characterized by its water-stress tolerance. In the last few years, there is an increasing interest in the cultivation of industrial hemp (Cannabis sativa L.) to manufacture therapeutic products derived from non-psychotropic cannabinoids and other secondary metabolites. This work evaluates the agronomical response of two industrial hemp cultivars (Carma and Ermes) subjected to different management practices. The trial was conducted during two seasons (2012-2013), from April to October. During this monitoring period, different plant densities (PD), sowing times (ST), irrigation doses (ID) and cropping systems (CS) were evaluated. At the end of each season, yield parameters (fresh and dry weight, dry weight of flowers and leaves, and the ratio between this late and total dry weight) were obtained. Moreover, the content of the most relevant cannabinoids (CBG, CBD, Δ9-THC, and CBC) were measured in both cultivars, and for the different growth conditions considered. According to our findings, both cultivars evidenced similar responses with significant improvements for the earliest ST (at the end of April) and the highest PD (33,333 and 16,667 plants ha −1). In relation to the ID, not clear responses were observed in terms of active biomass production, being the effects depending on the interactions between PD and ST. Finally, it was noticeable the improvements related to the active biomass production and cannabinoids content when plants were grown under plastic macro-tunnels (among 1.3 and 2 times higher, depending on the cultivar) in comparison to the obtained results under open field conditions.
Journal of Industrial Hemp, 2004
Hemp seed yields of the variety Fedora-19 in an on-farm scientific field experiment on small plots and in an on-farm evaluation in 11 hemp fields under practical organic growing conditions in Lower Austria were compared to give a realistic view of the variability of yields. Dry matter seed yields from the on-farm field experiment ranged from 127 to 143 g m Ϫ2 . Under practical growing conditions, yields ranged from 34 to 151 g m Ϫ2 in the sample plots. The reported hemp seed yield after combine harvesting, drying, and cleaning was between 324 kg ha Ϫ1 and 717 kg ha Ϫ1 . The results of the experiment show that harvesting by hand considerably influences yields. Yields of the manual harvest in sample plots indicate a high correlation with yields harvested by the combine harvester (R 2 = 0.91). The commercial yield is 71% of the yields recorded in sample plots in the fields. Our data questions the transfer of results and conclusions drawn from the data of scientific field experiments that employ manual harvest to that of practical circumstances, and support the notion of on-farm research.
Response of hemp (Cannabis sativa L.) to integrated application of chemical and manure fertilizers
Acta agriculturae Slovenica
The investigation of various nutrition systems in hemp plays an influential role in improving its production. An experiment was conducted in University of Birjand, Iran, during 2013-2014, in which manure (0, 10, 20, and 30 t.ha-1 of cow manure) was considered as the main plot and the combination of nitrogen (0, 50, and 100 kg N ha-1 as urea) with phosphorus (0 and 80 kg P ha-1 as triple superphosphate) fertilizers was considered as factorial in subplots. The type of soil fertility management had no significant effect on the percentage of female plants. Applying 20 t.ha-1 of manure plus 100 kg N ha-1 produced the highest biological yield, seed, and leaf extract. The highest oil content was obtained by applying a maximum of 50 kg N ha-1 without the use of phosphorus. The 30 t ha-1 manure plus 100 kg N ha-1 increased the leaf harvest index and decreased seed harvest index. Nitrogen consumption also increased the seed oil content and yield. Phosphorus increased the biomass and extracts ...
Response of hemp to plant population and nitrogen fertilisation
BACKGROUND. Hemp (Cannabis sativa L.) used to be a traditional industrial crop in many regions of Europe and of the World. After many years of aban-don the crisis of agriculture and the need for natur-al raw materials cast a renewed interest over this crop. In the frame of the EU project "HEMP", field experiments were carried out to evaluate the effect of agronomic factors over yield and fibre quality. METHODS. The effects of plant density (from 30 to 250 plants m -2) and available nitrogen (100, 160, and 220 kg ha -1) on fibre hemp were studied at Cadriano (BO) over three years 1996 -1998. These two factors were studied on different genotypes, sowing and har-vest times. Significant results for major crop para-meters are reported. RESULTS. Results confirmed that optimal production is obtained with a plant density of 90-100 plants m -2 . The weight of a single plant decreased exponential-ly as plant density increased. The same trend was ob-served in different years and with...
Agronomy
Given the growing interest in multipurpose hemp crop, eight monoecious cultivars were compared in a two-year trial for quantitative and qualitative yield in a Mediterranean environment characterized by a temperate and humid climate with hot summers. All hemp cultivars were evaluated for yield potential of (i) seed plus stem at seed maturity, and (ii) essential oil yield from inflorescences harvested at full flowering. The second goal was set to test the ability of cultivars to supply new seeds after the removal of inflorescence at full flowering. Among the cultivars, Fedora obtained the best results for seed (0.79 and 0.52 t ha−1) and vegetable oil yield (0.17 and 0.09 t ha−1) normally and with inflorescence removed plants, respectively. Futura, conversely, showed the best results for inflorescence (3.0 t ha−1), essential oil (9 L ha−1), and stem yield at seed maturity (8.34 t ha−1), as means across the two years. The cultivars studied generally reached the grain-filling stage durin...
Agronomy of fibre hemp (Cannabis sativa L.) in Europe
Industrial Crops and Products, 2000
Fibre hemp may yield up to 25 t above ground dry matter per hectare (20 t stem dry matter ha − 1 ) which may contain as much as 12 t ha − 1 cellulose, depending on environmental conditions and agronomy. Its performance is affected by the onset of flowering and seed development. Effects of cultivar and management on yield and quality were tested at three contrasting sites in Italy, the Netherlands and the UK in three years, making use of standardised protocols for experimental design and research methodology. Highest yields (up to 22.5 t dry matter ha − 1 ) were obtained in Italy when later cultivars were used. Attainable yields proved slightly lower in the Netherlands and much lower in the UK. The quality of the cellulose was relatively stable over the growing season, but lignification may proceed rapidly some time after flowering. Crop development was very rapid and crops maintained green leaf area for a long time, thus radiation interception was considerable. The radiation use efficiency changed during development. It was lower after flowering (about 1.0 g MJ − 1 PAR) than before (about 2.2 g MJ − 1 PAR). Growing earlier cultivars to obtain some seed set advanced the reduction in radiation use efficiency. Nitrogen proved to affect yield only slightly. A relatively small amount of fertiliser will be adequate to cover the crop's needs. Plant density declined during growth in a site-specific manner when it was high initially. Very low plant densities may not show this self-thinning but reduced yield and (especially) quality. Final plant densities were proven to depend more on initial plant stands than expected from literature. This was true at all three contrasting sites and in the different years. Nitrogen and plant density hardly interacted within one site. Results suggest that hemp can yield large quantities of useful cellulose when ecologically adapted cultivars are sown in proper plant densities. The cultivation is environmentally friendly with little harmful accumulation or emission of chemical inputs. More research on ideotyping is required and breeding efforts should be broadened.