Original article Earthworm assemblages as affected by field margin strips and tillage intensity: An on-farm approach S.J. Crittenden a, * , E. Huerta b , R.G.M. de Goede a , M.M. Pulleman a a Department of Soil Quality, Wageningen University, P.O. Box 47, 6700 AAWageningen, The Netherlands b El Colegio de la Frontera Sur, Unidad Campeche, Av. Rancho Polígono 2-A, Col. Ciudad Industrial, Lerma, Campeche, Campeche c.p. 24500, Mexico article info Article history: Received 24 February 2014 Received in revised form 10 November 2014 Accepted 26 November 2014 Available online 3 December 2014 Keywords: Earthworm species Field margin strips Non-inversion tillage Non-cropped landscape elements abstract Earthworm species contribute to soil ecosystem functions in varying ways. Important soil functions like structural maintenance and nutrient cycling are affected by earthworms, thus it is essential to under- stand how arable farm management influences earthworm species. One aim of arable field margin strips and non-inversion tillage is to enhance agrobiodiversity, however their influence on earthworm species assemblages remains unclear. In particular, on-farm studies conducted over multiple years that capture variability across the landscape are rare. The current study monitored earthworm species assemblages on 4 farms in Hoeksche Waard, The Netherlands, from 2010 to 2012. It was hypothesised that arable field margin strips (FM) and non-inversion tillage (NIT; a reduced tillage system that loosens subsoil at 3035 cm depth) would have higher earthworm species abundances (epigeics and anecics in particular), soil organic matter, and soil moisture than adjacent mouldboard ploughing (MP) fields, and that earthworm numbers would decrease with distance away from FM into arable fields (MP only). FM contained a mean total earthworm abundance of 284 m 2 and biomass of 84 g m 2 whereas adjacent MP arable fields had only 164 earthworms m 2 and 31 g m 2 . Aporrectodea rosea, Lumbricus rubellus, Lumbricus terrestris, and Lumbricus castaneus were significantly more abundant in FM than adjacent arable soil under MP. However, no decreasing trend with distance from FM was observed in earthworm species abundances. A tillage experiment initiated on the farms with FM showed that relative to MP, NIT significantly increased mean total earthworm abundance by 34% to 275 m 2 and mean total earthworm biomass by 15% to 51 g m 2 overall sampling dates and farms. L. rubellus, A. rosea, and L. terrestris were significantly more abundant overall in NIT than MP. FM and NIT positively affected earthworm species richness and abundances and it is noteworthy that these effects could be observed despite variation in environmental conditions and soil properties between samplings, farms, and crops. Higher top-soil organic matter and less physical disturbance in FM and NIT likely contributed to higher earthworm species richness and abundances. The anecic species L. terrestris (linked to water infiltration and organic matter incorporation) was more abundant in FM, but densities remained very low in arable soil, irre- spective of tillage system. © 2014 Elsevier Masson SAS. All rights reserved. 1. Introduction Functional agrobiodiversity (FAB) programs are being imple- mented to reverse negative impacts of agricultural land-use intensification. Practises such as non-crop areas (i.e., field margin strips), reduced tillage, and crop diversification aim to promote above and/or below-ground biodiversity and function [1]. Earth- worms play important roles in soil nutrient and organic matter dynamics, and soil structure formation [2] and are strongly affected by soil pH, organic matter, and soil moisture [3]. Arable cropping and soil tillage affect earthworms through mechanical damage, reduction and vertical redistribution of organic matter, changes in soil water regime, and habitat disruption [3e6]. Ecological groups of earthworms [7] play important roles in determining certain soil functions [8]. Epigeic earthworms live and feed at the soil surface and contribute to organic matter incorporation and decomposition, anecic earthworms also feed at the soil surface but create deep vertical burrows and are considered most important for continuous soil pore formation and water infiltration [8,9]. Endogeic * Corresponding author. E-mail address: Steve.Crittenden@gmail.com (S.J. Crittenden). Contents lists available at ScienceDirect European Journal of Soil Biology journal homepage: http://www.elsevier.com/locate/ejsobi http://dx.doi.org/10.1016/j.ejsobi.2014.11.007 1164-5563/© 2014 Elsevier Masson SAS. All rights reserved. European Journal of Soil Biology 66 (2015) 49e56