Impact of Nitrogen Nutrition on Cannabis sativa: An Update on the Current Knowledge and Future Prospects

Abstract

Nitrogen (N) availability represents one of the most critical factors affecting cultivated crops. N is indeed a crucial macronutrient influencing major aspects, from plant development to productivity and final yield of lignocellulosic biomass, as well as content of bioactive molecules. N metabolism is fundamental as it is at the crossroad between primary and secondary metabolic pathways: Besides affecting the synthesis of fundamental macromolecules, such as nucleic acids and proteins, N is needed for other types of molecules intervening in the response to exogenous stresses, e.g. alkaloids and glucosinolates. By partaking in the synthesis of phenylalanine, N also directly impacts a central plant metabolic ‘hub’—the phenylpropanoid pathway—from which important classes of molecules are formed, notably monolignols, flavonoids and other types of polyphenols. In this review, an updated analysis is provided on the impact that N has on the multipurpose crop hemp (Cannabis sativa L.) due to its renewed interest as a multipurpose crop able to satisfy the needs of a bioeconomy. The hemp stalk provides both woody and cellulosic fibers used in construction and for biocomposites; different organs (leaves/flowers/roots) are sources of added-value secondary metabolites, namely cannabinoids, terpenes, flavonoids, and lignanamides. We survey the available literature data on the impact of N in hemp and highlight the importance of studying those genes responding to both N nutrition and abiotic stresses. Available hemp transcriptomic datasets obtained on plants subjected to salt and drought are here analyzed using Gene Ontology (GO) categories related to N metabolism. The ultimate goal is to shed light on interesting candidate genes that can be further studied in hemp varieties growing under different N feeding conditions and showing high biomass yield and secondary metabolite production, even under salinity and drought.

Effect of Vermicompost Doses on Canabis Sativa Photosynthesis-Related Parameters, Growth and Yield

“…As far as mineral nutrition of hemp plants is considered, mainly nitrogen fertilization effects have been studied so far [1], [17], [18] [20], [28]. In contrast, vermicompost as a form of organic fertilizer contains significantly higher proportion of plant-available P and K (Table 1).…”

“…Biology, and uses and cultivation techniques of hemp have been thoroughly reviewed recently [3], [4]. More recent reviews on other important aspects of hemp cultivation emphasize large scientific and practical interest on this crop [17], [21].…”

“…In respect to mineral nutrition of hemp, mainly effect of nitrogen has been studied so far [17], [18], [20], [26], [28], supporting the nitrophilous status of the crop [25]. However, due to growing concerns for environment protection and increased agricultural sustainability, more environment-friendly means of fertilization needs to be proposed and approved also for hemp production.…”

Silicon‐induced mitigatory effects in salt‐stressed hemp leaves

“…In textile hemp, after 2 weeks of salt stress (200 mM NaCl), smaller xylem vessels in the hypocotyl have been observed (Guerriero et al 2017a) as a response to lower the incidence of cavitation. In addition, a decrease in the number of bast fibres, especially secondary ones, was observed (Landi et al 2019).…”

Can Manipulation of Soil Microbiota Enhance, Stabilize and Sustain Cannabinoid Production?

“…In addition to the sex and maturity of the plant, biotic and abiotic stresses also affect cannabinoid biosynthesis (Doorenbos et al 1971;Fetterman and Turner 1972). In addition, photoperiod (Valle et al 1978), temperature (Bazzaz et al 1975;Chandra et al 2011), nutrients (Bócsa, Máthé, and Hangyel 1997;Coffman and Gentner 1977;Landi et al 2019) and ultraviolet light (Lydon, Teramura, and Coffman 1987;Magagnini, Grassi, and Kotiranta 2018;Pate 1994), are among the factors that impact cannabinoid biosynthesis. However, as Cannabis is widely grown in indoor conditions with diverse growing substrates, artificial light and temperature control, these factors are not sufficient to stabilize ratios of THC and CBD in the plants, which brings another level of complexity to cannabinoid production and standardization.…”