Assessment of earthworms as an indicator of soil degradation: A case‐study on loess soils

Abstract

Soil degradation restricts the development of agriculture, and the degree of soil degradation is related to land use type, and efficient evaluation methods are helpful for the timely implementation of remedial measures to ensure soil sustainability. Earthworms are directly affected by the deterioration of soil properties during the degradation process. The feasibility of using earthworms to assess soil degradation, however, still needs to be verified. In our Loess Plateau study, earthworm biomass, density, and diversity (Shannon-Wiener, species richness, and Pielou's evenness) were investigated under nine different land use types (natural woodland, shrubland and grassland; planted woodland, shrubland and grassland; and cropland, orchard, abandoned land) and we analyzed their relationships with soil degradation. Our results showed earthworm biomass, density, and diversity associated with a low degree of degradation were significantly higher than those associated with a high degree of degradation. Earthworms can comprehensively characterize the physicochemical properties and biological characteristics of soils under different land use types. Linear correlations showed a significant relationship between the soil degradation index and the earthworm indices, indicating that the latter could be used to effectively evaluate and represent the degree of degradation of soils on the Loess Plateau over a certain degradation range. Nevertheless, this evaluation method requires further validation before wider use.

Effects of different earthworm ecotypes on soil nutrients distribution under straw return management in a maize agroecosystem

“…Earthworms escape from soil after inserting the electrodes into soil and running the device at low voltage. The density and biomass of each earthworm ecotype were determined before the experiment through a 30 × 30 m 2 quadrat survey in local maize fields (Li et al, 2021). The densities of earthworms in EP, EN, and EM were 25 epigeic, 17 epi‐anecic, and 12 epigeic plus 8 epi‐anecic earthworm individuals m −2 , respectively.…”

“…Straw return to the field effectively improves the abundance and diversity of soil fauna (Y. P. Li et al, 2021). Earthworms are among the most common soil macrofauna taxa and play an important role in farmland ecosystem functioning.…”

“…However, information regarding how the incorporation of earthworms and straw into cropland is limited. Li et al (2021) revealed that two species belonging to different earthworm ecotypes, Eisenia fetida (Savigny, 1826, epigeic) and Metaphire guillelmi (Michaelsen, 1895, epi‐anecic), can be found in loess soil farmlands.…”

The Shadow Values of Soil Hydrological Properties in the Production Potential of Climatic Regionalization of the Czech Republic

“…The main reasons for this include increased concentration, intensification and specialization of crop and livestock production without sufficient consideration of natural, site-specific soil and climatic conditions [16][17][18][19]. In terms of new methods for measuring soil degradation, monitoring of earthworms may also be of interest, where a correlation has been shown specifically between the number of earthworms and the degree of soil degradation [20].…”

Microarthropods and vegetation as biological indicators of soil quality studied in poor sandy sites at former military facilities

“…Biota plays a crucial role in many soil processes and functions (Pulleman et al, 2012). Any changes in properties of the soil can influence the abundance, species composition, and activity of the biota (Kladivko, 2001;Yi et al, 2021). There are several methods to access soil quality based on fauna.…”