|KORUCU, TAYFUN - Kahramanmaras Sutcu University|
Submitted to: Encyclopedia of Soil Science
Publication Type: Book / Chapter
Publication Acceptance Date: 1/11/2016
Publication Date: 2/22/2017
Citation: Shipitalo, M.J., Korucu, T. 2017. Structure and earthworms. In: Rattan, L., editor. Encyclopedia of Soil Science. Third edition. Boca Raton, FL: CRC Press. p. 2212-2215. doi: 10.1081/E-ESS3-120053787.
Technical Abstract: Earthworms are an important part of the soil ecosystem and an indicator of soil quality. Sometimes referred to as ecosystem engineers, they play a pivotal role in maintaining soil productivity. Their burrowing, feeding, and casting activities alter the physical, chemical, and biological properties of soil. As a result, earthworms can increase aeration, infiltration, aggregate stability, pH, porosity, and plant available nutrients. Their abundance and species composition can be affected by soil properties such as pH, texture, water content, and temperature as well as management practices such tillage, crop rotation and manure, fertilizer, and pesticide applications. The availability of crop residues and other organic materials, which serves as their food source, is usually the most important management factor affecting earthworm abundance. The 3000+ known species of earthworms can be classified into three ecological groups based on feeding and burrowing habits: litter-dwelling epigeic species, shallow-burrowing endogeic species, and deep-burrowing anecic species. Burrows created by anecic species can play a critical role in facilitating preferential flow of water and agrochemicals through the soil profile. Endogeic and anecic species can accelerate mineralization of plant residues while simultaneously enhancing aggregation and stabilizing organic matter within soil aggregates. Consequently, their net impact on carbon sequestration is uncertain. Earthworm populations and their contributions to soil structure can be maximized by keeping tillage to a minimum, retaining or adding crop residues and manures to soil and limiting the use of pesticides that are toxic to earthworms.