SOIL MICROBES, ORGANIC CARBON PROTECTION AND PLANT PRODUCTION IN CONSIDERATION WITH EARTHWORMS: A REVIEW

Earthworms have been well demonstrated to have beneficial effects on soil microbes, soil structure, water retention and plant growth in different terrestrial ecosystems. However, the interactions between environmental stressors and various species of earthworms and the subsequent effect on soil microbes, organic matter, soil structure and plant growth are still uncertain. The purpose of this analysis was to test 1- the impact of environmental stressors on earthworm behaviour. 2- the effect of various earthworms on soil microbes, plant growth, soil structure and the carbon cycle. We noted that less fatal temperatures are generally not known, but higher fatal temperatures range from 25 to 48°C. Earthworms have a role to play, depending on the nature of organic residues, in both the formation and degradation of soil aggregates. Improvements in microbial biomass and plant growth have been established according to temperature, soil toxicity, soil type, earthworms abundance, organic residues types and field conditions. While a great deal of analysis has been carried out on the role of earthworms within the soil ecology, such a review identifies important knowledge gaps, particularly in the determination of the impacts of earthworm species on the soil structure, microbial biomass and plant productivity, in particular since most papers focused on European species and overlooked the role of earthworms in the arid landscape. Further research is recommended to compare the impacts of different earthworms species on soil microbes and plant growth in various soil types, earthworm abundance, field conditions, organic residues locations, inorganic fertilizers, pesticides, fertile or non-fertile soils and diverse conditions of drought and moisture.