How do earthworms influence soil fertility?
The accidental introduction of earthworms to North America may have been the best outcome of contact between the early settlers and native peoples. While the Indians suffered from lack of exposure and immunity to European diseases, the fertility of many North American soils was greatly enhanced through the recycling of organic matter by earthworms. The activity of earthworms is most easily appreciated by comparison with the situation in regions where they are absent: the decomposition of organic matter there is slow, such that layers of litter accumulate on the soil surface and fail to be incorporated into the soil. More specifically, the activity of earthworms is important to the agriculturist in four respects, in that they: • improve soil structure • mix and till the soil • aid in humus formation • increase the availability of plant nutrients The burrowing of earthworms improves the physical structure of the soil, creating channels through which plant roots may more easily penetrate
