Soil biodiversity in dairy pastures: a pilot study in 2005 Maria - PDF document

Soil biodiversity in dairy pastures: a pilot study in 2005 Maria Minor Centipede Flatworm Slug Spider Slaters

Millipede Snail Harvestman Predatory Ground beetle Ground beetle head Earwig

Why soil animals? • Soil health is critical for ensuring the long- term sustainability of agricultural production systems • Management practices, which positively or negatively impact soil biota, similarly impact soil structure and fertility Earthworms Pilot Study Soil mites: Feed on soil fungi and bacteria • The diversity of soil micro arthropods in dairy pasture soils • Comparison of soil biodiversity in two dairy farmlets with conventional and organic management Soil mites in organic and Soil mites: conventional farmlets Predators • Sampling – 2 dairy farmlets (organic + conventional), 5 paddocks, 1 sample/paddock • Objectives: – what are population density and biodiversity of soil 400 µ mites – is sampling size sufficient? – are the two farmlets different?

Sampling 5 cm Data summary • 10 samples • 129 mites • 38 species Average species richness of soil mites in Average density of soil mites in organic and organic and conventional dairy farmlets. conventional dairy farmlets. 10.0 20000 Average no. species/ sample Mite Density (ind. / m2) 8.0 16000 6.0 12000 4.0 8000 2.0 4000 0 0.0 Organic Conventional Organic Conventional

Conclusions Average density of soil mites Oribatida in organic and conventional dairy farmlets. • Soil biodiversity was different in two farmlets 20000 Mite Density (ind. / m2) • Soil biodiversity was higher in organic farmlet 16000 12000 • Observed differences may be attributed to differences in management 8000 • need more than 1 pair of sites to be sure 4000 • One group – soil mites Oribatida – are particularly promising as indicators 0 Organic Conventional Funding: Massey University Organic-Conventional Dairy Systems Trial