Effects of Eisenia fetida population size on Lactuca sativa growth and productivity in model ecosystems
T.I. Zyubanova, O.M. Minaeva, E.E. Akimova, N.N. Tereshchenko
Section: Methodology and research methods. Models and forecasts
Artificial ecosystems are a convenient tool for studying the environmental effect on the functioning and interrelation between different elements in a model biosphere. An increase in the productivity of artificial ecosystems can be associated with the introduction of natural decomposers (earthworms), which alter the qualitative and quantitative composition of the soil microbiota, accelerate the processes of organic matter mineralization, increase the suppressive activity of substrates, and positively affect plant growth and development. In laboratory experiments, we evaluated the effect of a biotic factor (Eisenia fetida population) on model system productivity (Lactuca sativa plants). Earthworms were introduced at 6, 12, 25, 37, and 62 individuals per kg substrate (peat and 10 % of cattle manure). At the experiment’s finish, each plant’s height, leaf area, biomass (fresh and dry), photosynthetic pigment content, and photosystem II photochemical activity parameters were measured; earthworms and cocoons were counted; and the earthworms were weighed as well as worm cast. It was found that earthworms reproduced successfully in all microcosms, increasing their population. The earthworm population’s size in the microcosm affected the lettuce plants’ vegetative growth and physiological and biochemical parameters. The earthworms also significantly affected lettuce productivity and photochemical quenching coefficients. The effect of earthworm population size had a classical ecological form and could be described by an optimum curve (Shelford’s law of tolerance). Maximum plant productivity and vegetative growth were achieved with 25 and 37 earthworms per kg substrate. These data can be extrapolated to the biosphere’s natural elements and can be used to develop artificial ecosystems and increase greenhouse system productivity.
Keywords: earthworm, lettuce, microcosm, photochemical activity of photosystem, photosynthesis, productivity, Shelford’s law of tolerance
Article published in number 1 for 2026 DOI: 10.25750/1995-4301-2026-1-027-035
ISSN 1995-4301
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