Optimisation of Nitrogen, Phosphorus, and Potassium for Soilless Production of Cannabis sativa in the Flowering Stage Using Response Surface Analysis

Abstract

Following legalisation, cannabis has quickly become an important horticultural crop in Canada and increasingly so in other parts of the world. However, due to previous legal restrictions on cannabis research there are limited scientific data on the relationship between nitrogen (N), phosphorus (P), and potassium (K) supply (collectively: NPK) and the crop yield and quality. This study examined the response of a high delta-9-tetrahydrocannabinol (THC) Cannabis sativa cultivar grown in deep-water culture with different nutrient solution treatments varying in their concentrations (mg L–1) of N (70, 120, 180, 250, 290), P (20, 40, 60, 80, 100), and K (60, 120, 200, 280, 340) according to a central composite design. Results demonstrated that inflorescence yield responded quadratically to N and P, with the optimal concentrations predicted to be 194 and 59 mg L–1, respectively. Inflorescence yield did not respond to K in the tested range. These results can provide guidance to cultivators when formulating nutrient solutions for soilless cannabis production and demonstrates the utility of surface response design for efficient multi-nutrient optimisation.

Nitrogen Source Matters: High NH4/NO3 Ratio Reduces Cannabinoids, Terpenoids, and Yield in Medical Cannabis

“…The remaining N was supplied as N-NO 3 – , to a final uniform level of 200 mg L –1 N in all treatments. This level was previously demonstrated to be within the optimal range for medical cannabis cultivation ( Bevan et al, 2021 ; Saloner and Bernstein, 2021 ). Throughout the remainder of the experiment, the plants were cultivated under a short photoperiod (12/12 h light/dark) for the induction of inflorescence development.…”

“…Boron and Mo were added from the fertilizers B-7000 and Bar-Koret, respectively (Israel chemicals, Tel-Aviv, Israel). The concentrations of the three major macronutrients used for fertigation in the present study (200 mg L –1 N, 60 mg L –1 P, and 100 mg L –1 K), were selected to be within the optimal range for medical cannabis plant development and function, following on previous studies that reported plant responses to a range of supply rates ( Saloner et al, 2019 ; Bevan et al, 2021 ; Saloner and Bernstein, 2021 ; Shiponi and Bernstein, 2021b ). The irrigation solution was made once weekly and the pH of the solution was adjusted to 5.6–6.0.…”

“…We have recently identified a sensitivity of cannabinoid and terpenoid production in drug-type (medical) cannabis to mineral nutrition, including N ( Saloner and Bernstein, 2021 ) and P status ( Shiponi and Bernstein, 2021b ), and humic acid supplementation ( Bernstein et al, 2019b ). Progress was also made in understanding the nutritional requirements of the cannabis plant at the vegetative phase of development ( Saloner et al, 2019 ; Saloner and Bernstein, 2020 ; Shiponi and Bernstein, 2021a ), plant response to organic fertilization and interaction between nutrients ( Caplan et al, 2017 ; Bevan et al, 2021 ), plant architectural manipulation ( Danziger and Bernstein, 2021b , c ), and drought stress ( Caplan et al, 2019 ). The current study was undertaken to study the effects of N assimilation from an ammonium (NH 4 + ) vs. nitrate (NO 3 – ) N source on medical cannabis morpho-development, physiology, and secondary metabolism.…”

Impact of Harvest Time and Pruning Technique on Total CBD Concentration and Yield of Medicinal Cannabis

“…The importance of optimizing indoor systems has increased due to the demand for yield maximization and improved efficiency of growing systems [ 13 ]. Final yield quantity and quality of inflorescences are highly variable and depends on numerous factors such as genotype [ 14 , 15 , 16 ]; the agronomic practices, such as irrigation and fertilizer regimes [ 17 , 18 , 19 , 20 ], light spectra [ 14 , 21 ], intensity [ 22 , 23 ] and photoperiod [ 24 ]; plant density [ 25 ]; environmental conditions (humidity and temperature) [ 12 ] and the influence of biotic and abiotic stresses [ 26 , 27 ]—including pruning and defoliation techniques [ 28 , 29 ]—and finally, the duration of the vegetative and generative period. Thus, so many differences can be found for reported yield of medicinal cannabis currently in literature.…”

Extraction of Radix trichosanthis Polysaccharides for Potential Antihyperlipidemic Application

“…It was simple and easy to implement but could not be comprehensive enough to investigate the interaction of each factor [ 19 ]. RSM is another empirical modeling technique that allowed simultaneous optimization of multiple factors on a larger scale with fewer test units than traditional designs [ 22 ]. It not only saved lots of times and resources but also accounted for the interaction of experimental factors.…”