TOP 10THINGS ABOUT EARTHWORMS

1.Increase organic matter

       Earthworms feed on soil and dead or decaying plant remains, including straw, leaf litter, and dead roots. They are the principal agents in mixing dead surface litter with the soil, making the litter more accessible to decomposition by soil microorganisms. Animal dung is also an attractive food for many species of earthworms. The following farming practices provide food for earthworms. Permanent pasture: Permanent pasture provides organic matter as leaves and roots die and decay. Pasture slashing and manure from grazing animals are also good sources of organic matter in the pasture.

2.Reduce use of some fertilizers and fungicides

       Highly acidifying fertilizers such as ammonium sulfate and some fungicides reduce worm numbers. Researchers have found that orchards sprayed with Bordeaux or other copper sprays contain few earthworms and have peaty surface mats and poor soil structure.

3.Keep soil moist

      Worms can lose 20% of their body weight each day in mucus and castings, so they need moisture to stay alive. Groundcover such as pasture or stubble reduces moisture evaporation. Decaying organic matter (humus) holds moisture in the soil. Some species burrow deep into the soil in dry times and are inactive until rain 'reactivates' them.

4.Improve drainage

      Worms need reasonably aerated soil, so you may need to drain or mound soil in wetter areas to prevent waterlogging.

5.Reduce soil compaction

     It is difficult for earthworms to move through heavily compacted soil, keeping vehicle and animal traffic to a minimum in wet conditions.

6.Reduce cultivation

      Plowing soil reduces earthworm numbers. Researchers have found that after four years, zero-tilled paddocks had twice as many worms as cultivated soils. However, shallow cultivation may not affect worm numbers.

7.Protect from climatic extremes

     Earthworms are intolerant of drought and frost and do not like dry sandy soils. They are active only when the soil is moist and are inactive when it is dry. Organic matter cover helps reduce the effect of climatic extremes and retains soil moisture.

8.Improved soil structure

     Earthworm casts cement soil particles together in water-stable aggregates. These can store moisture without dispersing. Research has shown that earthworms that leave their casts on the soil surface rebuild topsoil. They can bring up about 50 t/ha annually in favorable conditions enough to form a layer 5 mm deep. One trial found worms built 18-cm thick topsoil in 30 years.

9.Improved nutrient availability

     Worms feed on plant debris (dead roots, leaves, grasses, manure) and soil. Their digestive system concentrates the organic and mineral constituents in the food they eat, so their casts are richer in available nutrients than the soil around them. Nitrogen in the casts is readily available to plants. Worm bodies decompose rapidly, further contributing to the nitrogen content of the soil.  Worms often leave their nutrient-rich casts in their tunnels, providing a favorable environment for plant root growth. The tunnels also allow roots to penetrate deeper into the soil to reach extra moisture and nutrients. Earthworm tunneling can help incorporate surface-applied lime and fertilizer into the soil.

10.Mix and aggregate soil

     Charles Darwin calculated that earthworms could move large amounts of soil from the lower strata to the surface and carry organic matter down into deeper soil layers. As they consume organic matter and mineral particles, earthworms excrete wastes in the form of casts, a type of soil aggregate. A large proportion of soil passes through the guts of earthworms, and they can turn over the top six inches (15 cm) of soil in ten to twenty years.