Earthworm community ecology

Earthworms are a significant component of below-ground systems. They are ecosystem engineers and provide ecosystem services, such as increased soil fertility, soil porosity and crop productivity (Spurgeon et al. 2013).

Eight pasture mixtures were selected using a constrained simplex-centroid design with three functional groups; grasses, legumes and herbs. There was a constraint imposed on the design so that there was at least 40% grass in each mix, therefore no more than 60% legume or herb (after Cornell 2002). This was repeated at three levels of species richness, with 1, 2 or 3 species per functional group (24 mixtures). Earthworms were sampled at one nitrogen rate in the experiment (90 kg/ha N).

The response of earthworms to varying plant species and functional group richness will be monitored for two years.

Cornell, J.A. (2002) Experiments with Mixtures: Designs, Models, and the Analysis of Mixture Data, 3rd edition. Wiley, Chichester.
Spurgeon, D.J., Keith, A.M., Schmidt, O., Lammertsma, D.R., Faber, J.H. (2013) Land-use and land-management change: relationships with earthworm and fungi communities and soil structural properties. BMCEcology, 13, 46.