Earthworms are commonly called “ecosystem engineers” due to their ability to modify soil structure, digging the soil and contributing to the flow of oxygen, water and carbon dioxide. Moreover, earthworms eat organic matter and break down the soil. This, allow bacteria and fungi to release nutrients on soil, which are an essential feeding source for plants.
Considering the current challenges in food production and agriculture, it is important to study earthworm possible effects on plant production. Some studies have stated that earthworms can stimulate plant production by controlling pests and diseases; stimulating microbial plant symbiosis; producing plant-growth regulating substances; increasing nutrient availability and producing changes in soil.
A recent study shows that earthworm presence in agriculture lands leads to a 25 % increase in crop yield and 23% increase in aerial biomass. These effects vary depending on the crop residues, the earthworm density and of course the kind and intensity of fertilization. An interesting finding suggests that earthworms help releasing nitrogen from crop residues and so they could be of increased importance for farmers who do not use fertilizers.