Effects of dairy cow treading pressures and food resources on invertebrates in two contrasting and co-occurring soils

Abstract

It is often difficult to compare the effects of land use on soil invertebrates across different soil types, as management practices are often adjusted to compensate for soil differences. A mosaic of two contrasting and co-occurring soils offered a unique opportunity to examine the influence of common management practices on soil invertebrates (macrofauna, mesofauna, and nematodes). Treatments established on a well-structured Andosol soil and co-occurring poorly structured Gleysol included a legume-based pasture grazed at 2.3 cows/ha and nitrogen (N) fertilised pastures grazed at 3 and 3.8 cows/ha, with the 3.8 cows/ha treatment also receiving maize supplementation. Low abundance (<13 000 individuals/m2) and diversity (four species) of Oribatida was a feature of both soils, reflecting the low porosity of the two contrasting, co-occurring pastoral soils, despite the Gleysol soil being more susceptible to treading than the Andosol. The lack of difference might reflect the ongoing disturbance from livestock treading on both soils. Nematode trophic groups behaved most predictably across both soils, with plant-feeding and bacterial-feeding nematodes increasing with the use of N fertiliser. Despite potentially more organic material available for incorporation into the soil profile with increasing inputs of N fertiliser and use of feed supplement, lower abundances of anecic earthworms, Collembola, and Oribatida are reported. Both direct and indirect effects of livestock treading on the decomposer community in intensive systems might be factors limiting the incorporation of organic matter from the soil surface into the profile to sustain soil carbon.