ABSTRACT
This chapter summarizes the major effects of earthworms on soil properties and plant growth and the effects of agricultural management practices on earthworm populations. Earthworms can have a major impact on the rhizosphere by their feeding, casting, and burrowing activities. Different species of earthworms occupy different niches and are often grouped by their feeding or burrowing habits. The influence of earthworm burrows on water flow is greater on soils that have a low soil matrix permeability. Organic materials and mineral soil are mixed intimately during passage through the earthworm gut and are excreted as casts. Root growth can be increased, especially in subsoils or moderately dense soils, by the presence of earthworms or their burrows. Agricultural management systems affect earthworm populations and activity by affecting the amount, quality, and location of food for the earthworms and by changing the physical and chemical properties of the soil.
