Assessing the Possibility to Cultivate Industrial Hemp (Cannabis sativa L.) in Sandy Agricultural Soils of Brandenburg under Water Scarcity and Nutrient Deficiency

Abstract

Industrial fiber hemp (Cannabis sativa L.) is an annual crop that requires minimal agricultural inputs and has a high potential to improve soil organic matter (SOM) accumulation in sandy soils, including soil fertility and yields. Hemp cultivation, due to rapid growth and high biomass production, in addition to its deep-seated and entrenched roots, has vast potential in carbon (C) sequestration and nitrogen (N) accumulation. The research aims to analyse industrial hemp species Santhica 27 feasibility for fiber cultivation and biomass production in water-scarce and nutrient-deficient sandy soils of Brandenburg. The impact of high (142 plants·m− 2) and low (71 plants·m− 2) planting densities on hemp´s morphological development and productivity, expressed as yields, is also assessed. The results showed that the dry condition with a water deficit of 168.9 mm during the growing period was the main factor significantly impeding hemp`s morphological development and fiber yields. Control treatments with the precipitation sum of 242 mm planted in a lower planting density had on average, significantly taller plants of 122 cm with greater total biomass yield of 3.74 t·ha− 1 dry weight compared to simulated water-scarce dry treatments, with the lowest plant height and total biomass of 69 cm and 1.91 t·ha− 1, respectively, when planted in high density. Although the N content in the original sandy soil was below 1 g·kg− 1, the dry environmental conditions had prompted N accumulation up to 35 N g·kg− 1 in hemp biomass, 18 N g·kg− 1 in lateral roots, and 13 N g·kg− 1 in tap roots. High calcium (Ca) content was found in hemp biomass and lateral roots, whereas potassium (K) content was greater in tap roots. The results suggest that a lower hemp planting density for hemp cultivation should be considered in a water-scarce and nutrient-deficient environment. Moreover, the elemental analysis showed that hemp parts contain considerable amounts of macronutrients, which could be of great importance to the sandy soil´s total nutrient-pool enrichment.