Plant Growth and Root Morphology Are Affected by Earthworm-Driven (Eisenia sp.) Changes in Soil Chemico-Physical Properties: a Mesocosm Experiment with Broccoli and Faba Bean

• Published in: Journal of soil science and plant nutrition 2023-09, Vol.23 (3), p.4078-4090
• Main Authors: Reyes, Francesco, Sorgonà, Agostino, Briones, Maria J. I., Crecchio, Carmine, Sofo, Adriano
• Format: Article
• Language: English
• Subjects: Aeration; Agriculture; Biomass; Biomedical and Life Sciences; Bioturbation; Broad beans; Broccoli; Carbon; Climate change; Ecology; Eisenia; Environment; Experiments; Flowers & plants; Leaves; Life Sciences; Macroporosity; Mesocosms; Microorganisms; Moisture content; Morphology; Nitrogen; Nutrient content; Oligochaeta; Original Paper; Parameters; Physical properties; Plant growth; Plant Sciences; Plant species; Plants; Plants (botany); Population studies; Soil chemistry; Soil fertility; Soil improvement; Soil properties; Soil Science & Conservation; Soil water; Species; Stomata; Vegetables; Worms
• ISSN: 0718-9508; 0718-9516
• DOI: 10.1007/s42729-023-01325-0

Earthworms are “ecosystem engineers” that improve soil water and nutrient content, soil macroporosity, and aeration, and provide suitable habitats for microbial populations. This study aimed at defining if the presence of epigeic earthworms ( Eisenia sp.) affected the growth and development of two plant species ( Brassica oleracea and Vicia faba ) via the modifications of soil chemico-physical properties. A mesocosm experiment, in which plants were grown outdoors for 4 months with or without earthworms, was performed. The two plant species were selected based on their different habitus and root architecture and morphology. Soil macroporosity ( M soil ) and water holding capacity ( WHC soil ) were determined. Earthworm-driven bioturbation ( B soil ) was measured by filling mesh bags with artificial soil. Earthworm abundance and biomass, together with plant morphometric parameters (root and leaf morphology by imaging and microscope techniques), were measured at the end of the trial. The presence of earthworms increased M soil (on average +16%) and WHC soil (on average +9%) and this was accompanied by a remarkable degree of B soil . In most of the cases, earthworms enhanced plant growth in the two plant species studied, with a significant positive influence on the majority of the shoot and root traits. A significant increase of stomatal density (on average +24%) occurred in the leaves of both the plant species in the presence of earthworms. Our results confirmed the hypothesis that bioturbation by Eisenia sp. had a significant positive effect on plant growth, independently from the plant species cultivated, and that these growth-promoting effects were mediated by changes in soil chemico-physical parameters. By taking into account the essential role of earthworms in maintaining healthy soils and the vegetation they support, soils can become more resilient against environmental perturbations and climate change.