Macrofauna Abundance and Composition in No-till and Cover Cropped Surface Soils in the San Joaquin Valley, CA.

We determined total macrofaunal abundance and taxonomic richness after fifteen years of no-tillage and standard tillage with and without cover crops at the conservation agriculture systems comparison site in the San Joaquin Valley, California as part of a broader effort to characterize biodiversity in these systems. There was an interaction between tillage and cover crop for total macrofauna abundance with the combination of no-tillage and cover crop resulting in greater abundance (632 individuals m-2 for the no-tillage with cover crop versus 224 individuals m-2 for the standard tillage without cover crop). Earthworms were predominantly present in no-tillage plots and particularly in those with cover crops. Macrafauna diversity, indicated by taxonomic richness, also seemed to be impacted by both cover crops and tillage, but to a lesser extent. Ants (Formicidae), earwigs (Forficula auricularia), and woodlice (Armadilliadium) accounted for the highest numbers of individuals. These data add to an emerging overall characterization of how these practices impact soils in this arid, irrigated region of historically high agricultural productivity.