Individual study: Earthworm density and biomass tended to increase with increased fertilizer input and stocking rates, in Ireland.
Curry J.P., Doherty P., Purvis G. & Schmidt O. (2008) Relationships between earthworm populations and management intensity in cattle-grazed pastures in Ireland. Applied Soil Ecology, 39, 58-64
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Reduce management intensity on permanent grasslands (several interventions at once)
A replicated, randomized study of pasture at three sites in Ireland (Curry et al. 2008) found that overall, earthworm (Lumbricidae) density and biomass tended to increase with management intensity (nitrogen fertilizer input and stocking rate), but that results varied with site. At Solohead there was no significant relationship between management intensity (N fertilizer input: 80, 175, 225 and 350 kg N/ha; stock rate: 1.75–2.5 cows/ha) and density or biomass. At Johnstown Castle, density and biomass increased with fertilizer input (0, 225 and 390 kg N/ha/year), but the effect was only significant in spring (density: 140, 235, 280/m²; biomass: 60, 115, 160 g/m² respectively). At Grange, biomass, but not density, was significantly higher in the 225 kg N and 2.4 cow units/ha treatment than the 100 kg N and 1.7 cow units/ha plots in autumn (92 vs 60 g/m²), but not spring (69 vs 58 g/m²). However, out of ten species at Grange, only two were significantly more abundant with higher inputs; species abundance did not vary with input at the other sites. Treatments were laid out as randomized blocks with five, three and four replicates (of 1-2 ha) for each treatment at Solohead, Johnstown Castle and Grange respectively. Earthworms were sampled using the formalin method within six 0.5 x 0.5 m quadrats/plot during one spring and autumn at each site from 2003 to 2005.