Biological mixture of brown algae extracts influences the microbial community of Lobivia arachnacantha, Lobivia aurea, Lobivia jojoiana and Lobivia grandiflora in pot cultivation

Research goal: Based on the information found in the literature, it has been verified that the use of biofertilizing algae can definitely improve plant quality, growth, and blooms. In this work, studies were conducted to evaluate whether the use of algae in the cultivation of ornamental cacti in pots can improve the growth, ornamental qualities and resistance to salt stress of plants that normally grow in environmental conditions different from our latitudes.

Materials and Methods: The experiments, started in September 2020, were conducted in the greenhouses of CREA-OF in Pescia (PT), Tuscany, Italy (43°54′N 10°41′E) on Lobivia arachnacantha, Lobivia aurea shaferi, Lobivia jojoiana and Lobivia grandiflora herzogli. The experimental groups were: i) group control, irrigated with water and substrate previously fertilized; ii) group control1, irrigated with water and substrate previously fertilized + 50 mM of NaCl once every 7 days; iii) group with algae, irrigated with water and substrate previously fertilized; iv) group with algae, irrigated with water and substrate previously fertilized + 50 mM of NaCl once every 7 days. On July 28, 2021, plant height and circumference, suckers’ number, number and length of thorns, vegetative and roots weight, flowers number, flowers life, plants dead from salinity stress, substrate microbial count, pH were analysed.

Results and Discussion: The test showed a significant increase in agronomic and quality parameters analyzed in plants treated with algae extracts on Lobivia arachnacantha, Lobivia aurea shaferi, Lobivia jojoiana and Lobivia grandiflora herzogli. In fact, the trial showed in agronomic terms an increase in plant height and circumference, number of new suckers, vegetative and roots growth, number and length of thorns and flowers number. In qualitative terms, theses treated with algae extracts have shown a significant increase in the flower’s life and greater resistance to salt stress. The trial also showed an increase in the microorganism’s number in the theses treated with algae and a lowering of the pH in the substrate. The results therefore suggest the presence of additional sources of carbon and energy in particular nitrogen and phosphorus that ensure the increase of microbial populations and influence their behavior.

Conclusions: This research paper highlights the potential of biofertilizer technology in terms of cost, environmental sustainability, and saline soil improvement. As in other experiments in the literature, the application of algae not only resulted in significant effects on plant growth but also influenced the development of microbial communities in the soil.