Worms key to soil health

The anatomy of an earthworm is hardly exciting stuff. But, Dr Tim Jenkins, a director at the Centre for Sustainable Agricultural Technologies in New Zealand, has a way of making the bodily functions of an earthworm sound kind of interesting.

He told about 80 farmers at a biological farming seminar in Gore recently that earthworms were a key driver of soil fertility.

A good number was 2000 worms per square metre or about 40 worms per spade, but he often found worm populations around 600 to 1000 per square metre because of poor quality soils.

To improve soil biology, Dr Jenkins suggested minimal cultivation, retaining clover, using lime flour and biological fertilisers and avoiding over-grazing.

Worms thrived in soil with a high pH but if it was too high, it would restrict the uptake of trace elements such as copper, zinc and manganese. A pH of 6-6.4 was ideal for a good balance of clover, trace elements and earthworm activity.

Dr Jenkins said the ideal soil texture was "crumbly" as this allowed worms to move freely through the soil which would promote good drainage.

The mucous the worms left behind would also help hold the soil crumbs together in a wet or dry spell.

Source; Stuff.co.nl