A simple and effective method for linking field investigations of earthworms and water infiltration rate into soil at pedon‐scale

Abstract

AbstractEarthworm density and activity may significantly contribute, amongst others, to soil physical properties such as water infiltration rate and permeability, and thus provide a desirable ecosystem service. In environmental field studies, investigations of the two soil physical properties are highly recommended. In practice, they are carried out separately in terms of time and space and, therefore, are typically closely connected. Therefore, the aim of this study was to test the feasibility of a combined investigation of earthworm population and infiltration rate in soil in field studies. The idea was to use an aqueous solution of allyl isothiocyanate (AITC) and a double‐ring cylinder for simultaneous measurements at the same pedon and, thus, without any spatio‐temporal deviation. Tap water was used as a control for the infiltration measurements with AITC. Another aim was to evaluate the plausibility of earthworm data received from those combined investigations. This was tested for some arable and grassland soils derived from various parent materials in W‐Germany differing in soil chemical and physical properties. Infiltration rates of AITC in soil were not significant different from tap water, neither for the different soils nor different land‐uses and at the different study sites. Earthworm population data revealed from AITC application with a double‐ring cylinder equipment were realistic and in line with previous investigations in the respected study area. Pearson correlation coefficient between earthworm biomass and infiltration rate of AITC was medium (R2 = 0.363).