Earth worms?

I have been doing some thinking about earthworms.

one thing is many times said that one can tell the health of your soil by the earth worms in it,  but in some places earth worms are not native.
http://www.waldeneffect.org/blog/Do_we_have_native_earthworms__63__/

and apparently there are different types depending on there eating and living habits,
http://www.cmg.colostate.edu/gardennotes/218.pdf

apparently the night crawler type I would think would be better for my soil as there is no much on top, 

OK would you suggest to introduce them?
and is there a easy way to introduce them on a large area, and to do it cheaply?

both red wigglers and nigh crawlers have been introduced around the house, and no ill effects have been noted, in the last 30 to 40 years they have been here, but I can not see necessarily any improvements either, they do not spread much by them selfs, mostly in the garden and some grass areas,

Where do you live? 

Worms mainly eat dead vegetation, and or microbes associated with dead vegetation.  Supply plenty of mulch and the worms will multiply.  Worms forage at the surface, but if you bury some mulch it can speed things up.

In autumn, I shred the leaves using a lawnmower then haul them to my compost/worm pit area.  I also add kitchen waste throughout the year.  Dry leaves are probably not the best worm food, but they are abundant.  The worms handle leaves better if they are finely shredded.  A solid mat of wet leaves is a barrier to worms.

I recently visited Greg Judy's farm in MO.  He has 150 worms per shovel!  These worms are a native type, smaller than night crawlers.  They thrive because high density grazing gives them a buffet of fresh hay, manure, and cast off grass roots.

plains of Colorado

I would say the same - it's not so much if your area has them, or how to introduce them as it is a question of is the environment supplying/sustaining them?  Worms server a purpose, without that purpose will there be worms?

Worms will multiply and do their thing if they have what they need - lots of decaying vegetation and/or poo (depending on the type of worm).

Since you have added worms to your soil, now may be the time to concentrate on supplying them what they like - leaf piles, hay piles, piles of vegetation, manure of any kind.  Basically return everything back to your soil, and bring in clean carbon/manure to boost the return.

I always have a private chuckle when I'm collecting free carbon/manure to bring home - I think wow they have no idea what they are giving away 
As I've read - the goal is to put-back more than we use/remove - so it's a bit of a numbers game.  The worms will help to return carbon/manure to the soil as available elements.

Good.  I do not see any reason to fear introducing non-native earthworms to Colorado.  Worms can be obtained at a bait shop.  I might start them off in a prepared environment some kind of bin, rather than just dumping them on the ground.  This way you can be sure they survive and start reproducing.  Too many worms in a bait container become stressed and eventually stop moving.  If they appear active, then they should be fine.  Worms hate sunlight and they hate drying out, always keep them moist.

Once you are ready to go outside, dig a pit fill it with manure, vegetable matter and dirt, add worms, done!  Worms travel best in soft loose soil, so make sure the vegetable matter is not a barrier (soft or shredded material works best).  Kitchen rubbish works well.  Worms have a difficult time going through coffee filters.  Banana and orange peels frequently mold before the worms completely consume them, shredding these helps the worms.  Meat scraps are not good worm food, maggots will get those.  I'd add everything you eat except meat.  If the meat were mixed with spaghetti or something, then I would add it too.  Melon rinds are probably the best worm food ever, they love 'em!

You could use many small pits to cover a large area.  Worms will tunnel outward from the pit and carry nutrients to the surrounding soil.  I would dig the pits about 2' deep and 1' across.  And, I would expect the worms to travel at least 6' out from the pit within a few weeks.

If you have a mowed lawn you want the worms to travel under, you can increase the amount of dead roots.  Allow the grass to fully mature (4-8 weeks) then mow it as low as possible.  Mature grass has far more roots, which it will discard to invest the energy in new shoots.  A lawn mowed weekly will not yield very much underground organic matter.

Here are a few ebooks about worms
http://www.journeytoforever.org/farm_library/oliver/balfour_intro.html

I have a couple of theories on worms.  I don't know if I read them a long time ago, or if I came up with them.  Please let me know if you have observations which refute these.

1.  Forest environments are low on worms.  The forest soil may be dominated by fungus which are hostile to worms.  Leaf litter is among the least palatable worm forages, they seem to let microbes break up the cellulose for a while.  Also tree roots are not ingestible by worms until other microbes have totally loosened them up.

2.  Worms need to tunnel below frost level in order to survive.  If the ground prevents deep tunneling or if the temperature changes too rapidly the worms might not survive.  A good sized compost pit can insulate worms through the winter.  If you want to have worms at high altitude, you may need to help them survive cold weather.

The only thing I'd refute is the part about worms and leaves.

I would say it depends on the leaves, pine needles for example, could make the soil to acidic for worms to abound.

The city collects and shreds leaves in the fall, and I get a couple of dump truck loads.  These are filled with worms in no time, and broken down into soil inside the pile in a few months over the mild winter here in the PNW.  So leaves - they love!  I also find the roots of many plants, bushes, etc. will try to take over my leaf piles after the worms have started to break them down.  These piles do have some pine needles, but not much.

i have more worms in my leaf mold pile than anywhere else. i also use forest leaf litter as worm bedding with no problems. and actually feel it makes for better castings high in fungal activity.

I used about 100 m[sup]3[/sup] of mostly maple and mulberry leaves.  I shred them with a lawnmower before burying.  It turns into perfect compost, but it takes a while.  There is probably 60% of the leaf material right now from October.  The worm content of my pit varies between 25-75 worms per shovel, going low in winter and getting higher about now.  Wherever there is a clump of solid wet leaves, the worms have not penetrated it.  Leaves on top of the pile don't get eaten much.  In contrast, kitchen waste averages less than 2 weeks to completely decompose.

I find that forest ecosystems often have leaf litter that lasts an entire year and sometimes up to 3 years.  Think about this, the tree takes most of the nutrients out of its leaves before dropping them.  If you walk the woods right now, you will find stinging nettles and such.  How many stinging nettle remains did you see in March?  How many oak leaves?

lack of earthworms in forest duff: maybe they just haven't been introduced yet.

I've read previously that the spread of earthworms is dramatically changing temperate forest ecosystems.  prior to earthworms, duff accumulates fairly thickly and provides habitat for all manner of fungus and invertebrates on up to reptiles and mammals.  after earthworms, the organic matter is broken down much more quickly and the duff layer can fail to form entirely, removing that particular habitat.  nutrients are then cycled much more quickly.

sounds a bit alarming, but I don't know that it's really such a disaster.  ecosystems change.

Earthworms prefer pH levels of 6.5 to 7.5

http://www.wormsrus.co.nz/aboutearthworms.html

Earthworms do not like acid soils with pH (CaCl2))* less than 4.5. The addition of lime raises pH and also adds calcium. Earthworms need a continuous supply of calcium, so are absent in soils low in this element. South Australian research found that earthworm numbers doubled when pH(CaCl2) rose from 4.1 to 6.7.

http://www.dpi.nsw.gov.au/agriculture/resources/soils/biology/earthworms


Warning.  Before following this link, locate an adjacent receptacle where you can vomit if necessary.
http://www.oxfordcroquet.com/care/worms/index.asp

Paul shares about his earthworm breeding experiment in this podcast: worm podcast