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

Earthworms

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

Pilot Study

• 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:

Feed on soil fungi and bacteria

400 µ

Soil mites:

Predators

Soil mites in organic and

conventional farmlets

• Sampling

– 2 dairy farmlets (organic + conventional), 5 paddocks, 1 sample/paddock

• Objectives:

– what are population density and biodiversity of soil mites – is sampling size sufficient? – are the two farmlets different?

Sampling

5 cm

• 10 samples
• 129 mites
• 38 species

Data summary

Average species richness of soil mites in

• rganic and conventional dairy farmlets.

0.0 2.0 4.0 6.0 8.0 10.0 Organic Conventional Average no. species/ sample Average density of soil mites in organic and conventional dairy farmlets. 4000 8000 12000 16000 20000 Organic Conventional Mite Density (ind. / m2)

Average density of soil mites Oribatida in

• rganic and conventional dairy farmlets.

4000 8000 12000 16000 20000 Organic Conventional Mite Density (ind. / m2)

Conclusions

• Soil biodiversity was different in two farmlets
• Soil biodiversity was higher in organic farmlet
• Observed differences may be attributed to

differences in management

• need more than 1 pair of sites to be sure
• One group – soil mites Oribatida – are particularly

promising as indicators

Funding: Massey University Organic-Conventional Dairy Systems Trial